Consumer Guide to the Best Diet Pills 2023

Buying diet pills can be a confusing process, but we are here to help.

The aim of this website is to help you find the best diet pill for your needs. We review all of the popular weight loss supplements that are around at the moment, asking the important questions such as: Does it work? Is it safe for me to take? And will I get my money back if things go wrong?

With a dedicated team of full-time writers, researchers and consumer experts, we uncover all the secrets around diet pills, including the facts that the manufacturers and marketers don’t want you to know about.

We check out the good, the bad, and the ugly, so you can be confident that when you buy a supplement you know exactly what you are putting into your body. We also uncover the scams that are sadly a part of the modern-day supplements industry.

We understand how hard it can be for the consumer to get to the truth about diet pills, which is why we are here to guide you through it.

To do this, we use a star rating system to assess how good (or bad) a product is. To help us make our decision we follow strict criteria based on key principles, such as the effectiveness of the diet pill, safety, price, guarantee, and trustworthiness of the seller.

It’s important to note that all our reviews are 100% independent and unbiased. We do earn a small commission from the products that we recommend, but this is essential for the smooth running of the website – and so we can keep the lights on. Rest assured that we would never approve a product that we feel is dangerous or useless in any way.

All good diet pills should conform to the following key points:

  • Reputable manufacturer that adheres to good manufacturing practice
  • Country of origin clearly marked
  • The supplement must work as claimed by the advertising
  • Contains only safe ingredients that have been tested
  • Does not cause dangerous or toxic side effects
  • Money-back guarantee for dissatisfied customers
  • Has genuine reviews from consumers
  • Clear instructions on how to take
  • Clear labelling showing the full ingredients list
  • Reputable sales policy – no dodgy strings attached or auto-billing scams

Not many supplements conform to our exacting criteria, but every now and then we find a gem of a diet pill that ticks all, or most, of these boxes.

It should also be noted that all supplements are different, so there are certain products that may not suit some customers but may be very effective for others. Our job is to provide you with the information you need so that you can decide on what is best for you.

So now you know what we look for in a diet supplement, let’s take a look at some products we like.

9 Best Products We’ve Seen



Best product for fat burning

What we like:

  • Over 300,000 customers
  • Active ingredients are in the correct, optimum doses
  • Active ingredients have significant clinical support
  • Vegan-friendly capsules.
  • 60-day money-back guarantee

What’s not so good:

  • May need smaller serving if you’re sensitive to caffeine

>> Read the full Watchdog review here

Phentaslim is a thermogenic weight loss supplement that boosts the metabolism for easier fat loss. It also provides extra benefits, such as decreased hunger cravings, increased energy levels, and improved mental performance. Very much an all-rounder that gets results, and an established winner, having now been on sale for nearly a decade.

Phentaslim contains some fantastic ingredients. Green tea is rich in antioxidants, and research has shown that when combined with caffeine, as it is here, it increases thermogenesis and fat oxidation in the body. The caffeine content of 190mg per serving is roughly the same as two cups of coffee, so you can expect a healthy energy boost to fire you up.

It also contains some useful amino acids, and vitamins and minerals for improving overall health and vitality levels. Other herbal ingredients are aimed at improving mood and energy, such as Panax ginseng that helps the body manage stress and improves wellbeing. All servings are in safe but effective quantities that compare well to vitamin supplements.

The ingredients have proven clinical research supporting them that is referenced on the official website, and the ingredient information is clearly listed, both on the bottle and online. Phenutra (previously Optimum Nutra) has clearly done their homework and found an effective formula.

Side effects are not an issue for most users. Unless you’re sensitive to caffeine, this is a superb product to take.

Customer feedback for Phentaslim is excellent too. According to Phenutra, thousands of customers have used these supplements and opinion is overwhelmingly positive. Results from independent review sites confirm this, with high ratings from customers and reviewers.

The price won’t break the bank either, particularly if you opt for a multi-bottle order – the more you buy, the more you save. You can mix and match as well, you don’t have to stick to just one of the products for the deals to apply. For both Phentaslim and Phentatrim the prices are:

  • 1 bottle of 90 capsules (30-day supply) costs £39 (39€/$49)
  • 3 month’s supply (buy two get one free) costs £78 (78€/$98)
  • 5 month’s supply (buy three get two bottles free) costs £117 (117€/$147)

Shipping is free worldwide too, which is a real bonus. The Phentaslim website is safe to buy from and there is a 60-day money-back guarantee.

Phentaslim is definitely our pick of the bunch. The premium formula will get your body burning the weight off. The pricing is good, there’s a guarantee, and shipping is free.


Hourglass Fit

What we like

  • Detailed website
  • Uses natural ingredients
  • Contains effective fat-burning ingredients

What we don’t like

  • Claims that it is specially formulated for women is just marketing hype
  • No money-back guarantee

As the name suggests, the claim behind Hourglass Fit is that is will help women get an “hourglass figure”. It is predominantly aimed at athletes and women who work out. It contains vitamins, herbal extracts and the appetite suppressant glucomannan.

Hourglass Fit comes from Roar Ambition, a supplements company with a range of well-known products to their name, including TestoFuel, Instant Knockout, and Prime Male. All supplements are manufactured in a GMP-approved facility, and the overall impression is of safety and good quality.

Hourglass Fit contains a concentrated capsicum extract called Capsimax, which has a thermogenic effect. The additional contents include B vitamins, zinc, and chromium for helping the body regulate glucose. Finally, there is black pepper extract Bioperine, which enhances the absorption of the other ingredients, and 5-HTP for boosting serotonin and counteracting hormonal hunger pangs.

This has recently been reformulated to contain more glucomannan, now 3000mg a day, which is double what it contained before. Suppressing the appetite is only part of the function of Hourglass Fit (as it’s predominantly a fat burner). The increase in glucomannan means it now meets the recommended and proven amount required to effectively reduce cravings.

There is not much in the way of independent customer feedback yet (just the customer testimonials on the product website), and unfortunately there is no money-back guarantee, so you are unable to claim a refund if things don’t work out.

Hourglass Fit costs £35.00 for a month’s supply of 120 capsules. Two month’s supply costs £70. Three bottles (3-month supply) comes with a free bottle and costs £105.

Shipping is free worldwide and sent from either the USA or the UK, depending on which is closest to you. If you are dissatisfied with the supplement you return the product to the same location.

We like that this product has the full ingredients information listed and that the supplement is aimed at boosting general health as well as the metabolism. Despite being marketing solely at women, it’s an overall good choice that should help most people with weight loss.


Boombod 7-Day Achiever

Boombod 7 Day Achiever

What we like

  • Delivered in post-box-friendly packaging
  • Contains glucomannan, a recognized weight loss ingredient
  • Does not cause bloating

What we don’t like

  • No money-back guarantee
  • Expensive if not on offer
  • Clearer directions are needed

A slightly different product this one. Boombod 7-Day Achiever is a powder that you add to a small glass of water and drink as a shot three times a day. It contains glucomannan, plus vitamins and minerals for a boost to health and energy levels.

As well as being available online, Boombod have got their products into Holland & Barrett, so you can actually buy it in-store if you are in the UK. Customers outside the UK can only buy directly from the Boombod website at present. It is delivered in post-box friendly packaging for added convenience.

Boombod 7-Day Achiever claims to help you lose a noticeable amount of weight in just seven days. The supplement is sold as sachets containing glucomannan as the primary ingredient. This natural fibre is effective as an appetite suppressant and has been approved by health authorities, including EFSA (European Food Standards Agency).

Each shot contains the recommended serving size of 1 gram of glucomannan, plus vitamins and minerals. You drink it three times a day, before meals, and the sachets are marked for morning use, lunchtime, and nighttime. Each has slightly different ingredients that are deemed suitable for the time you take it.

Although you are instructed to drink Boombod like a shot, it is very important to follow this up by immediately drinking a large glass of water. Glucomannan is an extremely safe ingredient, but because it works by expanding in your stomach it is crucial to wash it down properly, otherwise it could pose a choking risk.

This instruction is not really made clear enough and is a slight mark against what is otherwise a good looking supplement. The other ingredients are an impressive blend of vitamins and minerals to help you through morning, noon, and night.

Boombod is unlikely to cause side effects, but it may increase bowel movements or cause mild gastric discomfort for some users.

Feedback is generally positive on the official website and also on the Boombod social media pages.

Although Boombod costs a hefty £39.99 for one week’s supply, you can sometimes pick up a 2-for-1 offer from the official website and from Holland & Barrett.

This is an incredibly original, but pricey, product and a very good supplement that will help with weight loss.


Evolution Slimming Green Coffee

Evolution Slimming Green Coffee Pure

What we like

  • Clinical study showed 5.7% weight loss in 2 months
  • Minimal side effects, unless you’re sensitive to caffeine
  • Cost effective supplement

What we don’t like

  • Relies on caffeine – won’t suit everyone
  • No money-back guarantee

Evolution Slimming Green Coffee is a straightforward and inexpensive supplement that contains just one ingredient. Evidence suggests that green coffee bean extract has numerous benefits for health and weight loss, so it looks like a safe way to support any weight loss plan.

Evolution Slimming is a British company based in Kent. Their supplements can be purchased directly from the official website or via third party sites, such as Amazon.

Evolution Slimming Green Coffee contains only one ingredient: green coffee bean extract. But as single ingredients go, this isn’t a bad choice – it can boost metabolism without causing the jitteriness associated with other stimulants, and has minimal, if any, associated side effects.

The extract is in a powerful form of 10:1 strength, meaning that each 200mg capsule is the equivalent of 2000mg of pure green coffee extract per serving. As you take three pills per day, this delivers the equivalent of 6000mg of green coffee bean extract – so it’s pretty strong compared to other green coffee supplements on the market.

Green coffee bean extract is formulated from unroasted coffee beans. This means it retains high levels of chlorogenic acid, which, in combination with the natural caffeine contained in the coffee, increases the speed of the metabolism. Green coffee is also rich in antioxidants, so it has a general health-boosting effect too.

One month’s supply of 90 capsules costs £19.99 and there are savings on multiple orders. Prices are available in local currencies, including Euros and USD, and the company ships worldwide for very little cost.

Overall we think this is a top quality supplement that is worth a try if you are looking for a boost to your weight loss plan.



Astral Nutrition Thermaxin

What we like

  • Contains some good ingredients
  • Reputable looking company – safe to buy from
  • Money-back guarantee

What we don’t like about Thermaxin

  • Caffeine content is pretty high

Another fat burner on our list, Thermaxin was made to be used alongside an exercise program. It contains caffeine, green tea, and green coffee bean extract as the key ingredients. It seems to be the most popular product in the Astral Nutrition range.

Thermaxin is designed to increase the speed of the metabolism, burn fat, and improve energy levels. The ingredients profile looks effective – it contains green tea extract and caffeine, which can improve the results of resistance training, as well as help with fat loss.

There is also green coffee bean extract, which is high in chlorogenic acid and antioxidants and can improve fat burning. Cayenne pepper may add to the thermogenic effect as well, and amino acid L-Tyrosine can improve alertness.

This supplement looks to be pretty effective. There is quite a lot of caffeine, so it will have a stimulant effect, and although the listed caffeine level is 150mg (around two cups of coffee), the green coffee bean extract and green tea will add to this figure. So do be aware of the high caffeine content.

You can buy Thermaxin directly from the official Astra Nutrition website. It costs £34.99 for a bottle of 60 capsules (one month’s supply). Shipping costs are then applied at the point of sale.

All of their products are covered by a 30-day money-back guarantee, and if you go to the Astral Nutrition Facebook page you can obtain a discount code for 10% off your order.

Thermaxin appears popular with customers, who have generally posted good feedback on the website and on Facebook. There’s clearly lots to love, and we can see that Thermaxin works for the people who have already tried it.


Forza T5 Super Strength

Forza T5 Super Strength

What we like about Forza T5

  • Great price
  • Clinical support for ingredients
  • Will boost energy levels

What we don’t like about Forza T5

  • No money-back guarantee
  • High in caffeine

Another one for the fitness fans, Forza T5 Super Strength is a pre-workout supplement for boosting your energy levels and enhancing exercise performance.

The product used to contain a stimulant called Citrus aurentium (also known as bitter orange extract), but this has since been dropped for safety reasons.

Forza T5 Super Strength is an energy-boosting pre-workout supplement that is suitable for both men and women. The idea is that it will provide an edge to your performance, increasing mental alertness and physical performance.

Ingredients include a high serving of caffeine (300mg), which is roughly the equivalent of three cups of coffee. There is also green tea (again in a high serving), and this combination can lead to increased fat burning and improved exercise performance.

The supplement also contains a blend of vitamins and minerals, the amino acid Acetyl L-Carnitine, which may improve mental functioning, plus the herbal extracts cayenne pepper and Panax ginseng.

Stimulant side effects could be an issue for some users. Although Forza T5 Super Strength no longer contains Citrus aurentium, the caffeine serving is high. The recommended upper limit of caffeine is 400mg a day, about four cups of coffee, so this supplement will not suit you if you are sensitive to caffeine or continue to drink coffee or tea in high quantities.

A real plus point for Forza T5 Super Strength is that it is very inexpensive if you buy directly from the official website. A bottle of 60 capsules (one month’s serving) costs just £14.00. UK shipping is an additional £4.50, and international delivery is available.

A money-back guarantee is not offered beyond a standard returns policy (which includes free return shipping), but the low price does lessen the risk considerably.

Overall, we think that Forza T5 Super Strength looks very reasonable and will suit many users who are looking to boost their workouts.

The principal ingredients – green tea and caffeine, are well known for increasing metabolism and helping weight loss. The other ingredients help support weight loss and general health. It is such a well-priced supplement that you get much more than you pay for.



What we like

  • Cheap compared to other products
  • MyProtein is a reputable brand
  • Good for boosting the performance of those with active lifestyles

What we don’t like

  • No money-back guarantee
  • Not as effective for those who don’t already work out and exercise frequently

Unlike the products mentioned above, Thermopure isn’t a fat burner or an appetite suppressant, it actually aims to boost exercise performance and energy levels. Even though the advertising does not make any actual weight loss claims, it looks like it offers some great support to fitness goals with few side effects.

Thermopure comes under the MyProtein label. This is a sports nutrition brand from an award-winning UK company called THG (The Hut Group) based in Manchester, UK. THG is a major company that operates worldwide, and MyProtein is a well-established and respected name in the bodybuilding and fitness communities.

The blend of ingredients is optimised for increasing energy and metabolism – and it certainly seems effective in this way. If you regularly exercise you should notice improvements in your workout sessions.

Ingredients include green tea, caffeine, and cayenne pepper – all known for their thermogenic effects. The serving sizes are ample, with 375mg of green tea and 198mg of caffeine per serving (the equivalent of around three cups of instant coffee, which is half of the recommended safe daily limit).

The other ingredient servings are equally significant and include L theanine, an amino acid in tea that causes energising yet calming effects, various vitamins, and the mineral chromium. There is also the amino acid L tyrosine, which can enhance energy levels, and finally, black pepper extract, which helps the body absorb the other ingredients.

The overall ingredients profile looks effective, although if you are used to taking strong fat burners and metabolism boosters that are high in stimulants, you might feel that this one is a little milder.

Customer opinion is largely positive. Although there are some negative comments, these are outweighed by the many positive reviews. Most people have found that this supplement increases energy, and some people mention associated weight loss when using Thermopure. Reported side effects are mainly related to caffeine sensitivity.

You can buy Thermopure directly from the MyProtein website. The good news for customers is that it is not expensive. A bottle of 90 capsules (one month’s supply of 30 servings) costs just £15.49, and a bottle of 180 capsules (two month’s supply) just £25.99. Shipping costs are applied at the point of sale, with UK shipping an added £3.99.

MyProtein also have regular promotional offers and discount codes available, so you may even be able to get a further reduction on what is already a great price.

There is no money-back guarantee with Thermopure, but the price is so good that we think it’s certainly worth a shot for anybody who wants to give a boost to their workouts.


African Mango Advanced

Evolution Slimming African Mango Advanced

What we like about African Mango Advanced

  • Massive 2400mg serving of pure African Mango extract
  • Published scientific data showed average weight loss of 12lbs in four weeks
  • Very affordable price

What we don’t like about African Mango Advanced

  • May cause bloating if you are not used to eating fibre
  • No money-back guarantee

African Mango Advanced is a straightforward weight loss supplement that contains 2400mg of African mango extract as the sole ingredient. Research has found that taking this superfruit can decrease hunger pangs, cholesterol, and your waistline, as well as boost fat burning and energy.

Evolution Slimming is a well-known British supplement company based in Kent. You can buy straight from the official website or from other online stores, including Amazon.

African mango (Irvingia gabonesis) is a tree that grows in West Africa that produces a fruit similar to a mango (hence the name). Both the fruit and the seeds are edible, but it is the seeds that have been studied for weight loss. The high fibre African mango seeds have undergone clinical tests and there is evidence that they may help reduce waist measurement and reduce cholesterol levels. The fruit is rich in antioxidants, so should improve general health and energy. One clinical test found that participants lost an average of 12lbs in four weeks.

According to the advertising, African Mango Advanced will boost fat burning and energy levels, decrease food cravings and LDL cholesterol, and improve the control of blood sugar levels. The serving size is very generous; original clinical trials looked at 300mg a day, but with this supplement the daily serving size is the equivalent of 2400mg, so it’s substantial.

Side effects may include mild abdominal pain, flatulence, headaches, or insomnia, but overall this ingredient is safe and well-tolerated by most users. Although bloating may be an issue if you are unaccustomed to eating fibre.

Customers who have used African Mango Advanced feedback positively, often mentioning their successful weight loss.

One month’s supply of capsules (60 capsules) costs £14.99, and you can save money on larger orders. Two month’s supply costs £24.99 and three bottles (three month’s supply) costs £34.99.

An ideal choice if you are trying to improve health and lose weight without using stimulants.


Astral Nutrition Overpwr

Astral Nutrition Overpwr

What we like

  • Easy to take
  • Contains glucomannan – a proven appetite suppressant
  • Contains no stimulants

What we don’t like

  • Levels of glucomannan are low
  • Expensive if the full recommended dose is taken

Created by Astral Nutrition, Overpwr is another appetite suppressant that contains glucomannan as the main active ingredient, plus a blend of vitamins and minerals to help support general health while you lose weight.

Glucomannan is a natural fibre that is proven to reduce the appetite by making you feel full, and therefore less likely to snack or overeat. It also helps prevent low blood sugar spikes and can aid digestive health by improving bowel function. As we’ve mentioned above, glucomannan is one of the few natural substances that has been approved as a safe weight loss aid by health organisations like the EFSA.

Although research has shown that taking 3g of glucomannan a day is the effective dose, the daily serving of Overpwr only adds up to 1500mg. This means to get the effective serving you would need to double up on the dose, which could become expensive.

That said, customer feedback is generally positive for this supplement and side effects do not appear to be an issue.

There is a money-back guarantee if you buy from the official website, but Astral Nutrition does not pay for the return delivery and charge an additional £6.00 admin fee.

If you buy Overpwr from the Astral Nutrition website it costs £34.99 for 60 capsules. If used as recommended, taking three a day, then your bottle will only last 20 days. If you did want to keep to the recommended serving size of glucomannan and decided to double the dose, 60 capsules would last only 10 days, so it can become an expensive option.

We love glucomannan supplements, and Overpwr is right up there with the best of them.

All You Need To Know About Diet Pills

As you can see from our list of top ten products, there is no such thing as a typical diet pill – there’s a lot of variation. Although all diet pills come with the aim of causing weight loss, they don’t all work in the same way.

For example, some diet pills help reduce your appetite, making it easier to resist snacking or eating too much at meals. Others prevent the absorption of calories in fats or carbs, so if you do overeat it does not add to weight gain.

Diet pills can also speed up your metabolism, sometimes with an associated energy buzz so that you lose weight more easily. Other diet pills use a variety of methods combined into one product.

Broadly speaking though, diet pills can be split into the following categories.

Fat Burners

The most popular type of diet pill on the market is the fat burner. So naturally, most of the supplements we review on the site are fat burners. Whilst they can be some of the best products around, they can also be some of the worst. Fat burners can vary a great deal in quality and effectiveness, so you do need to be careful about what you buy.

A fat burner has the simple aim of increasing the speed of the metabolism so that you can burn off more fat with less effort. In some cases, this means raising the temperature of the body in a process called thermogenesis.

Increasing the speed of the metabolism is usually done with the aid of stimulants, often caffeine, although natural ingredients that are high in antioxidants are also effective. One of the best fat burning combinations is green tea paired with caffeine, as clinical research has proven that this formula works.

You can also find stimulant-free fat burners that help to boost the speed of the metabolism without the stimulant effects.

However, there are some companies out there that cram all manner of useless or potentially dangerous, even borderline illegal, ingredients into their fat burners. But don’t worry about those, that’s why we’re here: to let you know which ones to avoid.

If you suffer from a slow metabolism and have low energy levels, a good quality fat burner is an effective support to weight loss. Many people enjoy the buzz of increased energy they can give you too. But it is worth noting that some fat burners do present some concerns, and some may contain little more than caffeine – something you could easily get from a cup of coffee.

Taking a fat burner can certainly work for some people, but this method of weight loss does not suit everyone.

Check out our full guide to fat burners right here.

Fat Binders and Fat Blockers

Fat binders… Fat blockers… The names are pretty interchangeable. These types of supplements are aimed at preventing dietary fat from adding to your weight, and if you generally consume a lot of fat in your diet they can help you lose weight without having to make too many dietary changes. Many well-known diet pills, such as Alli and XLS Medical Fat Binder, are fat binders, and they can be effective for some users.

They work by blocking a percentage of the dietary fat that you eat from being absorbed by your body and adding to body fat. They are composed of certain types of fibre that, once ingested, attach to the dietary fat molecules in the stomach. Once this happens the fat molecules are too big to be broken down by enzymes and absorbed by your body, so they are expelled as waste.

We hate to mention it but some fat binders are notorious for causing embarrassing side effects. Many people report spending a lot of time in the bathroom and can even experience the occasional “accident”, but effects will largely depend on the supplement you choose and how you take it. Other than that, fat binders are largely safe to use.

Just to be clear though, fat binders do not block ALL your dietary fats. The figure varies, and it is hard to prove what the exact figure is anyway. A supplement like XLS Fat Binder, for example, claims to block around 27% of fat, so if you have a high-fat diet, you should lose some weight even if you do not make too many dietary changes.

Fat binders/blockers do not work for everyone. If you don’t generally eat much fat they will not have much effect. In addition, taking a fat binder can lead you into a false sense of being able to eat what you want without gaining weight.

Check out our full guide to fat binders right here.

Appetite Suppressants

Appetite suppressants can be a good choice for you if your weight loss plans are generally derailed by hunger pangs, cravings, or overly large portion sizes. An appetite suppressant can help you resist those temptations and they are especially useful if you are trying to stick to a low-calorie diet.

Appetite suppressants fall into two main categories. The first is a fibre-rich supplement that fills you up by staying in your stomach, fooling your brain, body and appetite – triggering hormones into thinking you are full.

Supplements in this category contain ingredients such as glucomannan, which forms into a gel in your stomach and is very effective for steady weight loss. Other health benefits can include maintenance of blood sugar levels and lowered cholesterol levels. In general, appetite suppressants based on fibre are safe and effective. Glucomannan, for example, is approved by the European Food Safety Agency (EFSA) and has genuine scientific backing that shows it works as intended.

The other type of appetite suppressant is not so easy to define. Many diet pills based on stimulants have an appetite suppressant effect, as these types of stimulant affect the nervous system and can make you feel too jittery to eat. This type of appetite suppressant contains stimulants, such as bitter orange extract, that can cause the body to mimic the effects of stress, which decreases appetite. But this can also cause jitteriness, increased heart rate, and high blood pressure. This method of weight loss is not safe for long-term use and can cause a range of side effects in some users.

By contrast, an appetite suppressant that uses a fibre-rich ingredient, like glucomannan, is safe and effective and can help you lose weight without compromising your health.

Check out our full guide to appetite suppressants right here.

Carbohydrate (Carb) Blockers

Carb blockers are sometimes known as starch blockers. They have an effect similar to fat binders, but instead of blocking dietary fats from the body they block carbohydrates.

In recent years, carbs have come to be seen as the major cause of weight gain and obesity, hence why low carb diets like the Keto diet are popular. Although it can be difficult to cut out bread, rice, pasta, and potatoes, many people are finding that this type of low carb diet works for them.

A carb-blocking diet pill is derived from certain foods, such as bean extract or garcinia cambogia, which contain a group of chemicals called alpha amylase inhibitors. Alpha amylase is a digestive enzyme in the body that breaks down carbohydrates into smaller units which are then absorbed by the body. By preventing the alpha amylase from working, a percentage of the carbs are blocked from adding to weight.

Carb blockers are not always reliable though. Studies have shown that effects can vary and that the percentage of blocked carbs can vary too. One study found that although a good quality carb blocker blocked up to 97% of the digestive enzymes from working, this only resulted in 7% of the carbs being blocked from absorption.

However, if carbs are your particular issue you may find that a carb blocker can slightly improve weight loss results.

Other benefits to carb blockers may include a decrease in blood sugar spikes, making the return to normal blood sugar levels after eating much faster. Other research suggests that some carb blockers can help reduce appetite and cravings by acting on the appetite hormone ghrelin.

Carb blockers are generally safe for most people and, although they are only effective for people with a mid- to high-carb diet, you may find that they help with weight loss.

Check out our full guide to carb blockers right here.

Multi-Action Pills

Many diet pills use ingredients that can both suppress your appetite and increase fat burning. Often advertised as fat burners, because the prime benefit is to increase the speed of the metabolism, many dual action diet pills also work to suppress the appetite.

These types of diet pills sometimes contain stimulants that cause the body to mimic the effects of the “flight or fight” response – the body’s reaction to danger.

As we know, this causes effects such as sweating, increased heart rate and the loss of appetite. All of this can be effective for losing weight, but with the high risk of side effects, including issues around heart rate and blood pressure, this type of diet pill is not safe for everyone.

Some dual purpose diet pills contain so many different ingredients that they claim to do almost everything. You can sometimes find a range of ingredients associated with different weight loss benefits, such as bean extract for carb blocking, fibre for appetite suppression, and some added caffeine for increased energy, all rolled into one diet pill.

In most cases, multi-purpose diet pills like this are not as effective as supplements with only a few specific components. And although each individual ingredient may come with some evidence that it can help weight loss, low ingredient quantities often mean that effects are likely to be minimal.

Advertisers always tout the benefits of each of the ingredients while failing to point out that the serving size is often so small it is likely to be undetectable.

In addition, diet pills that claim to work in many different ways contain so many different ingredients they increase the risk of side effects.

Check out our full guide to multi-action pills right here.

Metabolism Boosters

Metabolism boosters are often interchangeable with fat burners because they both increase the speed of the metabolism. The difference is that metabolism boosters are generally aimed at improving exercise performance rather than weight loss, and these types of supplements can be much stronger.

Most metabolism boosters are aimed at athletes and bodybuilders looking for a way to make a workout more effective. As well as caffeine and herbal ingredients like green tea and green coffee bean extract, metabolism boosters sometime contain more dangerous stimulants, such as bitter orange extract or yohimbine.

Others may use ingredients that are said to increase the production of thyroid hormones. These types of supplements are often called T5 supplements, after the thyroid hormones Triiodothyronine (T3) and Thyroxine (T4).

Not all metabolism boosters are safe, but because they are designed to be used in combination with exercise the added stimulants can improve performance. If you are in general good health and have no underlying health issues you may find that a metabolism booster may help you maximise your workout.

When looking for a metabolism booster it is crucial to read through the ingredients list because, as with fat burners and dual-action diet pills, there is no standard formula. So the results and the risk of side effects can vary. Most reputable sellers will provide a list of potential side effects and health warnings. It is also important to read through these and to follow the directions. Most advice is to reduce the serving size when you first take a new supplement so that your body can adjust to taking it, and so any potential side effects are kept to a minimum.

Metabolism boosters are certainly not for everyone, but they can be effective and are quite popular.

Check out our full guide to metabolism boosters right here.

Super Greens

Sometimes labelled as superfood products, super greens are powdered supplements that you add to water and drink so you can increase your intake of fruit and vegetables.

The way they are marketed you could be forgiven for thinking that super greens are a healthy replacement for real fruits and vegetables. Unfortunately, they are not.

Don’t get us wrong, there are some health benefits to super greens, which we’ll come to in a minute, but you have to be realistic.

The bulk of the (usually pretty lengthy) ingredient lists consist of powdered forms of leafy greens like broccoli, spinach, and kale, etc. You’re also likely to find powder versions of numerous other fruits and veg, as well as healthy grains and grasses.

The problem with this is that fibre, along with lots of key nutrients, are lost when the real foods are converted into powder. So super greens should not be viewed as a direct replacement for proper food.

Pretty much all of the super greens products we have seen are expensive too. For the same price you could buy a huge amount of actual fruits and vegetables, which you can then chuck in a blender and make your own smoothie with even more health benefits.

That said, there are some benefits to superfood powders. For example, some contain extra ingredients that perform specific functions. We’ve seen super greens products that target digestion, metabolism, heart health, and energy levels. The extra enzymes, antioxidants, vitamins, and minerals are all good for the body, so will probably not do any harm.

A super greens supplement can also be of use on the odd occasion where you struggle to hit your target of five fruit and veg per day. Bear in mind though that a serving of super greens will only count for one of your five daily portions.

For us, super are not a vital purchase and will not directly help with weight loss. You would be much better off spending your money on actual fruits and vegetables.

Check out our full guide to super greens right here.

Keto Products

The keto diet is probably the most popular specialist diet out there right now, just like Atkins and Paleo have been in the past (although that’s not to say they don’t still have their fair share of committed followers).

The idea behind keto is to lose weight by putting your body into “ketosis”. This is a biological process whereby existing body fat is used as fuel in place of carbohydrates that you’ve eaten. The way to do this is through cutting way, way down on your carb consumption – we’re talking less than 5% of your total food intake.

It’s actually quite an effective route to weight loss, although there are some concerns. For one, it is very difficult to stick to. Eating so little in the way of carbs is a daunting prospect, and is something which your body will react a bit negatively to at first.

You can expect to feel nausea and fatigue, experience vomiting and diarrhoea, and go through other minor issues during the first few days. A phenomenon commonly known as “keto flu”.

This will eventually subside though and, should you brave it through this horrible period, weight loss should soon follow. But despite the positive outcomes and success stories from those who commit to the keto diet, there are still a whole host of products out there that claim to improve results or make the diet easier.

The supplement world can be tricky to navigate at the best of times, but when it comes to a sub-section as popular as keto it can be an absolute nightmare. For every actual keto-focused product, there are a dozen more that are no help at all yet still use the word “keto” in their name as manufacturers try to jump on the bandwagon.

In fact, there aren’t really that many supplements that can actually assist you with keto dieting. There are a couple of ingredients worth looking out for though. Products that contain BHB salts, for example. BHB (beta-hydroxybutyrate) may speed up ketosis by getting the body to use fatty acids stored in the liver as energy instead of carbs. This isn’t definitively proven, but if they do work as suggested, then BHB salts could reduce keto flu symptoms in those first few days.

Another potentially effective ingredient is MCT oil. MCT stands for medium-chain triglycerides, which is a type of fat that releases ketones into the bloodstream. Doing this can improve energy levels and mental functioning, something that keto dieters often struggle with when starting out.

Finally, supplements that contain vitamins, minerals, and antioxidants could be beneficial when on a keto diet. As fruits and vegetables are pretty restricted on the diet, key nutrients are not being consumed, so a product that can help you ingest these missing ingredients can be very useful.

It’s worth pointing out that you don’t actually need a supplement to successfully lose weight on the keto diet. They might be of some assistance in the ways mentioned above, but these products are not likely to be much use to anybody not on a keto diet. And then, of course, there are products that have nothing to offer keto dieters, but the word “keto” is still plonked into the name. Make sure you avoid these, as they will do you no good whatsoever. If you are in any doubt about a product, check out our reviews to see if something is worth taking.

Check out our full guide to keto products right here.

Detox Products

Detox products are just as popular as keto ones, and even more useless. The idea behind them is that they can “clean out your system” and make it easier to lose weight. It’s all a lot of nonsense though.

For one thing, the supposed benefits are incredibly vague. Lots of buzzwords and phrases are used in the marketing, but they are all pretty meaningless. Toxins, a cleaner system, detox the body – these are the typical soundbites used as selling points, but the exact nature of what they mean is never really revealed. For example, what actually are the toxins? Nobody ever explains.

Additionally, your liver and kidneys do a decent enough job of filtering out waste and any nasty chemicals that pass through your body. So there is absolutely no reason why you would need a product to help you with this.

The medical community routinely advise against the use of detox products, and rightly so – they are a waste of time and money.

All of these detox products are essentially laxatives and diuretics in disguise. The only noticeable effect from them is that you will be visiting the bathroom a lot more than usual. We’ve heard countless horror stories about people not even making it in time because the laxatives are so strong that the effects sometimes hit you without warning.

The frustrating thing about this is that because you are going to the bathroom so often, it can appear like you are losing weight, so people continue to fall for these products. This is not actually the case though. What really happens is that you lose water weight and can become severely dehydrated.

Taking this sort of product for that long is actually dangerous, with countless potential side effects, such as dehydration, diarrhoea, and a dependency on them, so it becomes difficult for the bowels to open with the use of a laxative.

By far the most common type of detox product is the detox tea, or “teatox” as it is commonly known. They are generally sold as 14- or 28-day detoxes. But there is no real reason why this should be so. It just seems like a convenient number for the marketers to work with and to charge exorbitant amounts for a few tea bags full of laxatives.

As well as the teas, we have seen detox coffees, juices, pills, powders, and every other type of product that unscrupulous companies can chuck a laxative into. They are all as bad as each other, and we do not recommend that you use any of them.

Check out our full guide to detox products right here.

Weight-Loss Shakes

Weight-loss shakes tend to fall into one of two categories: protein shakes and meal replacement shakes. They are pretty similar, but there can be some subtle differences between them.

A meal replacement shake is meant to do exactly that: replace a meal. Brands like Weight Watchers are famous for this sort of product. The shakes are generally less calorific than a full meal, but just as filling; at least that’s the idea. In reality, some are rammed full of sugar and other additives, making them less nutritious than first thought.

Alternatively, a protein shake will usually contain less additional ingredients, and is seen as a way for bodybuilders and other athletes to increase their protein intake and supplement their workouts for increased muscle gain.

There are several different types of protein that are used as the main ingredient in a protein shake. Whey is the most common, but alternative forms, such as hemp, soy, and pea proteins, are gaining in popularity.

How you use a protein or meal-replacement shake is the real key to whether they are effective or not. Living off of meal replacements is probably not sustainable, as your body will be crying out for lost nutrients, not to mention the taste and feel of real food. People who try to replace all of their meals with a shake often struggle after a couple of days, and quickly fall back into old habits. The best advice for meal replacement shakes is to use them sparingly; once a day, perhaps.

Protein shakes also be consumed in place of a meal, although they tend not to include additional vitamins and minerals like a meal replacement shake would. The best practice with a protein shake is to have one after a workout. The increased protein intake will replenish the muscles and make it easier to see results in the gym. But take note, this is only a good idea for those who expend a lot of calories in the gym. Drinking a protein shake on top of eating your regular meals will cause you to gain weight if you are not exercising regularly.

We say this about every type of supplement, but make sure you look at the ingredient list and nutritional information before you commit to buying a protein or meal replacement shake. You need to find one that suits your goals best, and doesn’t contain lots of sugar or useless filler ingredients.

Check out our full guide to weight-loss shakes right here.

Prebiotics and Probiotics

There is just one letter difference between the two words, but prebiotics and probiotics are different things entirely. Although they are linked.

Probiotics are the friendly bacteria that live in your body, particularly in your digestive system. There are trillions of these little guys living inside you at any one time, and they play a key role in digestive health, as well as helping to fight disease and improving your general health.

There are thousands and thousands of strains of probiotics, but the two most commonly found in supplements are the Lactobacillus genus and the Bifidobacterium family. There are also thousands of strains within these two families, which makes reading the ingredients on a probiotic supplement incredibly tricky as you try to figure out if a strain is any good.

Prebiotics, on the other hand, are compounds in fibre. They are the food for the friendly probiotics in your gut. Whereas probiotics are living organisms, prebiotics are not.

As with probiotics, there are also several categories of prebiotics. But nowhere near as many, thankfully. These is guar gum and beta glucan, plus a few almost unpronounceable types like xylooligosaccharides. All types of prebiotic are derived from fibre, but not all fibres are prebiotic. It’s a tricky business.

Neither pre- nor probiotic supplements are essential though. With a healthy diet, you can consume all the prebiotics you need. Eat plenty of yoghurt and wholegrains and you should be absolutely fine on that front. When it comes to probiotics, yes, they play an incredibly important role in the body, but most medical advice is that unless you have a specific condition, IBS for example, then there is really no need for a probiotic supplement. And if there is a genuine medical issue, we would recommend you speak to your doctor first, instead of trying to self-administer a probiotic product to save the day.

Check out our full guide to prebiotics and probiotics right here.

Fad Diet Products

While the vast majority of diet supplements fall into one of the categories mentioned above, there are the odd few that require a different classification. They are typically fads or gimmicks, and often become popular for a short while, before the trend ends and they disappear.

One common form of diet fad is the weight-loss patch. These are designed to work in the same way as a nicotine or HRT patch, with ingredients inside of it that seep into the body. But whereas the contents of nicotine and HRT patches are proven to have transdermal effects (i.e. through the skin), none of the ingredients in diet patches have any such scientific support for this way of delivery.

Some of these patches are also said to be able to spot reduce a certain area of fat – the stomach, for example – but again, this is just not proven. No evidence anywhere supports the idea behind spot reduction of body fat. When weight is lost, it is lost from everywhere, not just one specific place.

In a similar vein, we see lots of creams, sprays, and gels that claim to have weight loss properties. Just rub the solution into your skin and the ingredients are said to work. But these have the same problems as the patches. There is no evidence the ingredients will work in this way, and they certainly won’t affect a particular chosen area.

Another product we are seeing more and more of lately is the weight loss gummy. These are basically sweets and candies that you suck or chew, and contain the sort of ingredients you usually find in a diet pill.

These are certainly more promising than patches or creams. At least you are orally ingesting the ingredients in the gummies, instead of smearing them across your skin. That doesn’t mean they necessarily work though.

Gummies are often expensive too, and there is little choice currently available on the market – so you are still better off opting for a quality diet pill if you want to see results.

One of the newest fads doing the rounds is the weight loss vape. We’ve all seen (and smelt) e-cigarettes of various flavours whilst walking down the street, and it now appears that companies are putting weight loss ingredients into their formulas.

But, once again, there is no evidence that this method of ingredient delivery will work. Inhaling essential oils is not going to cause you to suddenly shed the pounds.

There are lots of other weird and wacky products out there. Magnets, belts, toe rings, underwear, and countless other types of equipment and gadgetry that are supposed to cause weight loss. None of it is proven, and none of them last. They are mostly just fads that have their fifteen minutes of fame, and then are (hopefully) never heard of again.

Check out our full guide to fad diet products right here.

Frequently Asked Questions

Now we’ve seen the type of products that are out there, let’s take a look at some common questions and concerns surrounding diet pills.

What is the safest over-the-counter diet pill?

When it comes to safety, the most important factor for any over-the-counter (OTC) diet pill is that it has a full ingredients list, so you know exactly what it contains before you buy. Many diet pills contain caffeine, for example, so if you are trying to avoid caffeine this type of supplement will not be suitable for you, but it’s perfectly safe for other users.

A reputable OTC diet pill will provide full ingredients information, including quantities, so there should be no unpleasant surprises when you take the supplement.

If you are trying to avoid stimulants, an appetite suppressant based on fibre such as glucomannan is safe and will be effective for most people.

If you are looking for a fat burner, a supplement with effective quantities of caffeine and green tea should be fine for most users. Other potential ingredients include cayenne pepper and green coffee. These natural ingredients are safe and effective in the correct quantities and most people can take them with zero risk to health.

Not all diet pills are side effect-free for everyone, but one of the most important features of Diet Pills Watchdog is to evaluate each supplement for safety. So by keeping an eye on our website you will be able to stay safe and know what to avoid.

What diet pills work fast without exercise?

If you can’t or don’t want to exercise, a supplement that reduces your appetite will help you reduce your calorie intake and so lose weight. A supplement that contains glucomannan, for example, will work without exercise and will help you stick to a calorie controlled diet. Do this and you could find that you can lose up to a couple of pounds a week. This is considered a safe rate of weight loss and adds up to a whopping 8lbs over the course of a month.

If mobility is an issue, switching to a healthier diet and taking a safe appetite suppressant is also the best way to go. Anything that helps you reduce your calorie intake does not require exercise.

Although fat burner supplements are often aimed at people who do exercise, supplements that contain moderate quantities of caffeine and other weight loss ingredients, such as green tea, green coffee, or cayenne, are natural thermogenics, which may help perk you up. A supplement that increases the metabolism will make weight loss easier, but it will require you to make dietary changes.

You don’t necessarily need to work out in order to lose weight. Although it is good for your health to be more active, you won’t have to dig out the lycra and running trainers. Simple lifestyle changes such as walking more, dancing, and taking the lift instead of the stairs will help keep you fit and healthy.

Are there any weight loss pills that actually work?

Here at the Watchdog we review numerous supplements and we can confidently say yes, there are plenty of weight loss pills that work. However, none of them work by magic. For best results, you do need to make some lifestyle changes, such as changing your diet and/or getting more active.

You don’t have to eat significantly less, but you may need to change your diet. You may not need to exercise, but if you can get more active it will help your weight loss and your health in the long run.

Check out our list of top diet pill supplements above to find the one that is best for you. If you struggle with appetite but find it difficult to be active, an appetite suppressant will probably work best. But if you lack motivation and energy, you will probably find that a good quality fat burner is more suitable to your needs, as it will help you get motivated, and the extra boost to your metabolism should help the pounds drop off. If you work out in the gym, a metabolism booster may help you maximise your efforts.

Weight loss pills work differently for different people; the secret is to find the supplement that works best for you.

Are natural diet pills dangerous or bad for you?

It’s sad to say, but even though most natural diet pills are safe, some can be extremely dangerous. Many natural extracts contain powerful chemicals and can be just as dangerous as synthetic ingredients. It can also depend upon the quantities contained in the supplement.

For example, caffeine is safe and well tolerated by most people, yet if taken to excess it can cause a range of side effects, including increased heart rate, blood pressure and insomnia.

Other stimulants are of more concern. Some diet pills contain natural substances, such as bitter orange extract, yohimbine or synephrine, which in high doses can be linked to causing strokes and other extreme side effects.

One of the most dangerous sources of natural diet pills are those that are manufactured overseas, especially in China. These often contain unspecified quantities of unknown herbal ingredients, and are usually unregulated by any sort of government or official health agency.

It’s important to keep this in perspective though. Really dangerous products are in a minority, and by keeping up to date with the latest reviews on Diet Pills Watchdog you can be sure to find natural diet pills from reputable suppliers that won’t pose a risk to your health.

Which slimming pills work best for men?

Slimming pills work equally well for men as they do for women. The problem is that because many slimming pills are targeted at women the advertising can be off putting for men.

Most men will not be attracted by a supplement that shows a female silhouette as a logo accompanied by images of young women laughing while eating yoghurt. Neither will all men be impressed by stereotypical male advertising that implies that they should be spending every waking hour in the gym.

In general, weight loss supplements for men stress the bodybuilding angle and talk about improved strength and obtaining lean muscle. If you do want to lose weight by working out at the gym then a supplement that boosts the metabolism may help. Equally, a fat burner supplement that contains safe amounts of caffeine and green tea can help increase energy levels and weight loss without leaving you feeling wired or unable to sleep.

Luckily, not all advertising is along male/female lines, and a slimming pill that works for women is going to work for men too.

The ingredients list is the real key to weight loss. A fat burner that contains natural ingredients such as caffeine and green tea is a good combination. If you do work out, you may find a supplement with additional amino acids that supports muscle building is also effective. An appetite suppressant based on fibre, such as glucomannan, will also work equally well for both men and women.

Which slimming pills work best for women?

Lots of slimming pills are aimed at women so that the companies can create appealing advertising – promising tempting advantages such as fast weight loss, improved health, and a reduction in a dress size. But with such a wide range of choices available it can be hard to pick out the good products from the inferior.

The best slimming pills for women follow the same criteria as the best slimming pills for men. This includes a full ingredients list that clearly states each serving of every ingredient. These may vary, but they should conform to clinical testing so that you know there is a good chance of it working, and without causing a risk to health. There should also be a money-back guarantee so that if things don’t go to plan you can claim a refund.

The type of slimming pill that is best for you will depend upon your own needs and lifestyle. If you are an active person looking to improve your exercise regime and fat burning, a fat burner may be effective. If you work out in the gym you may be tempted by a sports supplement that supports muscle building as well as fat loss – these are often aimed at men but can work just as well for women.

If you struggle with restricting your appetite you may find that a glucomannan-based appetite suppressant suits you best.

How much do the best diet pills cost?

The best diet pills are not necessarily the most expensive. We have seen some shockingly bad diet pills that are very expensive but still don’t work. We have also found some very reasonable supplements for a fraction of the price.

In general, it is best to avoid anything that is too cheap, as there is probably a reason for that. It could be that it contains cheap ingredients that won’t work. More worryingly, some cheap diet pills come with very little background information regarding their manufacture or the ingredients list.

It is never a good idea to buy a diet pill on price alone if you are going to be putting an unknown substance into your body. It just is not worth gambling with your health. At the other end of the scale, a weight loss supplement that is ultra expensive could be using the inflated price just to give the impression that it is good quality.

If a supplement is of good quality and comes from a trustworthy and reputable company, provides full ingredients information, and comes with a money-back guarantee you can trust, it is worth paying a little extra for.


Buying diet pills should be easy, but, as we’ve seen, it’s not always straight forward. There are so many products on the market that it is easy to become overwhelmed by the sheer volume of advertising.

Plenty of diet pills promise an easy way to lose weight, and they employ some very persuasive arguments. Diet pill advertisers know exactly how to push our buttons. They often tell us just what we want to hear and, although we all know deep down that we are unlikely to become slim in a matter of days, we never stop falling for the same old clichés.

But a reputable diet pill supplement CAN help you lose weight. There are some excellent products out there that will help you achieve your goals. Choosing the right diet pill for you can be a step towards a new healthy future.

The type of diet pill you choose will depend upon your own lifestyle and habits.

If you struggle with overeating or cravings, an appetite suppressant that contains glucomannan can be effective. This does not require exercise in order to work and it makes sticking to a calorie-controlled diet much easier.

Alternatively, if you struggle with motivation and are looking for general support, a fat burner will get you moving and help you shed those pounds faster. You will need to put some effort into using a fat burner for the best results, but most people find that this support makes the whole process much easier.

Working out at the gym and not sensitive to stimulants? A stronger fat burner or metabolism booster that diminishes your appetite while raising energy levels may be the way to go. And for people with a specific weight loss issue, such as eating too many carbs or too much fat, you may find a carb blocker or fat binder is effective.

People have lost weight successfully by using all types of diet pills; there really is no one size fits all solution. You do need to be realistic in your expectations though. A diet pill will not produce results instantly, so you should allow for a few weeks or even months before you start noticing a drastic improvement. After all, weight gain does not happen overnight either. It is often a slow process, so losing weight can be equally long-term, depending on how much you wish or need to lose.

We all have a factor that leads us to make the decision – an unflattering photo, or the fact that clothes suddenly feel tight – but we can’t expect the weight to suddenly fall off just because we have noticed it. According to NHS guidelines, a safe rate of weight loss is generally reckoned to be 2lbs a week, so keep this in mind and you could lose 8lbs in a month. A diet pill that offers support for safe and steady weight loss at this rate is more likely to work than a product that claims to make you lose 8lbs in a couple of days.

Another crucial factor is that taking a diet pill does require some input from you. Yes, you may find that by taking an appetite suppressant, a carb blocker, a fat blocker, or even a fat burner, you are able to lose a few pounds without making any changes to your diet and lifestyle, but you are not going to get the results that you want.

You do need to make some lifestyle changes in order to lose weight successfully, but with the aid of a suitable diet pill this process does not need to be painful or require superhuman willpower. If you choose the correct supplement and keep your weight loss plans realistic, you will succeed. There are thousands of success stories out there.

Once you have made the commitment to lose weight it helps to make your weight loss journey as easy as possible. Taking a weight loss supplement will get you on your way, and the more you can do for yourself by diet and exercise, the quicker you can reach your target weight.

For many of us this is not just about looking more attractive or being able to wear flattering clothes. There are numerous health reasons for losing weight, so what are you waiting for?

Further Reading

Check out our guide for full details on how to avoid diet pill scams and ensure that you will never be ripped off:

Diet Pill Scams and How to Avoid Them