Everything You Need To Know About Fat Binders

Fat binders may sound similar to fat burners, but they work in a completely different way. A fat burner helps you lose stored fat, whereas a fat binder prevents the fat from adding to weight in the first place.

Fat binders can be effective for weight loss, are easy to use, and come with very few side effects. You just take a pill before your meals and some of your dietary fat is removed from your body before it can be digested. This works for some users, and many people have lost weight using a fat binder.

So, let’s find out everything you need to know about fat binders.

What is a fat binder?

A fat binder is a weight loss supplement that decreases the amount of dietary fat that adds to your bodyweight. They usually come in the form of pills or capsules, but some fat binder supplements are sold as powders that you add to water and drink.

To use a fat binder, you take it before a meal – especially a high-fat meal. According to research, a fat binder should prevent about 25% of fats from being absorbed by the body, so it helps reduce calorie intake as well as blocking a proportion of unhealthy saturated fats.

Many fat binders are made of indigestible fibre. When taken, the fibre absorbs water and forms into a complex that attracts and binds fat. When this happens, the fat compound is too large to be broken down by the digestive enzymes, so it passes through the body and gets expelled as waste as urine and faecal matter.

Fat binders are often derived from cactus, Chitosan (a fibre made from seafood or fungus), or other fibrous compounds. Many fat binders contain patented fat-binding formulas such as Litramine – this is based on cactus and used in many named brands, such as XLS Medical.

There is also Orlistat, a pharmaceutical drug and medically approved fat binder that has undergone clinical testing. This prevents digestive enzymes in the pancreas from breaking down fat. Orlistat is the ingredient in Xenical, a prescription-only weight loss supplement, and the key ingredient in over-the-counter diet pill Alli.

Do fat binders work?

There has been extensive clinical testing into fat-binding ingredients. Some work; others not quite so well. As with all supplements, fat binders are not miracle pills and will work best when combined with improved diet and exercise. All of the clinical research mentions this important point.

Orlistat is a pharmaceutical drug that has undergone 100 clinical tests. It is the main component of Alli, an OTC diet pill, as well as Xenital, a prescription drug that is much stronger. One clinical test looked at 80 obese people with a Body Mass Index (BMI) of over 30 and split them into two groups. Compared to the placebo group, the participants taking Orlistat experienced noticeable improvements. Weight loss was 4.65kg compared to 2.5kg over 24 weeks. Waist circumference, BMI, cholesterol, and blood fat levels (triglycerides) were also improved.

Litramine is a fat binder based on cactus extract and acacia gum. Manufactured by major European supplements company InQpharm, it is the active ingredient in XLS Medical, BmiSmart I-Remove, and other supplements. Clinical evidence suggests that it will block up to 27% of dietary fats.

Other fat-binding components include Chitosan, a sugar fibre extracted from shellfish skeletons, or occasionally fungi, which may work as a natural fat binder – although evidence is mixed.

Maybe unsurprisingly, fat binders work best for people who are overweight and who already have a high-fat diet. Much of the clinical testing has been carried out on obese subjects, so although results do look convincing, if you are not similarly overweight, results may not be quite as good.

Do fat binders help you lose weight?

Fat binders seem to work best for people who have a lot of weight to lose. Clinical testing is usually carried out on obese subjects and results are often quite good. Do they actually work that well if you only have a few pounds to use? Such a group does not appear to have been included in clinical testing, but many people take fat binders such as Alli and in some cases they have lost weight. Of course, it all comes down to lifestyle, the way you use the supplement, and what else you are doing to lose weight.

Taking a fat binder is not a green light for overeating. Some of your dietary fats are blocked, but no fat binder will block them all. So if you take a fat binder expecting it to remove the damage of a fatty meal, cream cakes, and more, you will be disappointed.

A fat binder could lull you into a false sense of security, in the belief that all your excess fat will disappear down the toilet. In reality, only around 25% of your dietary fat will be excreted in this way. The rest will add to your bodyweight as usual.

The other issue with fat binders is that we don’t only eat fat, so its effectiveness is fairly limited. Although fat can be a major part of any diet, carbs, over eating, lack of exercise, and too many calories all contribute to weight gain.

What are the benefits of fat binders?

There are benefits to fat binders. This type of diet pill is not known for causing too many adverse effects, and will not affect your sleep patterns or make you feel jittery or on edge. They may cause some gastro-intestinal issues, but in most cases this type of supplement is safe for everyone to take.

When it comes to weight loss, a fat binder can be effective. There have been numerous clinical studies carried out on fat binders, and substances such as Orlistat and Litramine have been tested and found to work. Although fat binders do not block all fats, preventing around 25% of dietary fats from being absorbed by your body will help reduce calorie intake. In addition, it will block saturated fats and help reduce cholesterol levels.

A fat binder is one of the few supplements recommended by doctors. Xenical is a fat binder available on prescription, and Alli is available in pharmacies and has medical approval. Of course, you need to check that the supplement you are considering is suitable for you.

Make sure you check out the Diet Pills Watchdog site before you buy any supplement. We provide all of the information about most fat binders on the market, so you can guarantee that you won’t waste your money or endanger your health.

Are fat binders safe?

Fat binders are pretty safe, but this does not mean they won’t cause side effects – some fat binders are quite renowned for them. Alli, which contains Orlistat, a pharmaceutical drug, is known for causing explosive diarrhoea, urgent bowel movements, and leaking faecal content. Many users have experienced embarrassing accidents, coining the phrase “Alli oops!”. Although none of this is dangerous, it is a side effect that most of us could do without.

Prescription drug Xenical, which contains much higher levels of Orlistat than Alli, has been linked with causing liver damage. The FDA has insisted on a warning label, but later research published in the British Medical Journal suggests that liver damage is not a causal effect of taking Orlistat. If you are prescribed Xenical, ask your doctor for more information on this.

Many fat binders contain Opuntia ficus-indica, a type of cactus commonly known as prickly pear. This is often included as a branded product called Litramine. It appears to be safe, although you may experience mild side effects such as abdominal pain, oily spotting, bloating, and increased bowel movements or constipation.

Chitosan is another popular ingredient. This will not suit you if you have an allergy to shellfish, as it is derived from the exoskeletons of sea food such as prawns and shrimps, so it could cause an allergic reaction.

Some fat binders are based on grain fibre like FBCx, which is present in supplements such as Calorease. This can cause side effects if you do not consume enough fat for it to work.

Are fat binders a waste of money?

Fat binders can certainly be a waste of money. In our opinion, cutting back on your dietary fats BEFORE you eat them is a much more reliable method of weight loss than taking a supplement to remove the damage afterwards.

The amount of fat that a fat binder actually binds is debatable. Some supplements claim to block up to 30% of fats, others put the figure at around 25%. Some supplements pin this down to calorie content, claiming to help you lose 500 calories or similar from your daily calorie intake.

The problem is that this is all a bit vague. You can’t rely on it, and taking a fat binder can lull you into a sense of false security. Yes, your diet pill may help reduce dietary fats by 25%, but that still leaves 75% that can be added to your bodyweight.

That said, many people feel that a fat binder helps with weight loss and minimises the damage of an occasional fatty meal.

The problem is that a fat binder is not a fast method of weight loss. Although we always stress that steady weight loss over time, about 2lbs a week, is the best way to lose weight, some fat binders do little more than nothing. A study into Chitosan, for example, found that taking this over seven months resulted in the loss of only 1lb. At this rate, you are never going to become thinner and healthier.

What’s the difference between fat burners and fat binders?

You could be forgiven for getting fat burners and fat binders mixed up, but they really work in opposite ways.

A fat burner helps you burn fat off by increasing the metabolism, increasing body heat, and boosting your energy levels. In many cases, a fat burner will decrease appetite too – so you are less likely to snack.

Fat burners can be effective for weight loss, often containing ingredients such as caffeine and green tea. The strength and ingredients of fat burners can vary a great deal; they can be some of the best and some of the worst weight loss supplements on the market. Many people find that a fat burner does help with weight loss, but it all depends upon the supplement you choose, as well as your own physical makeup.

A fat binder works in a different way: it prevents some of the dietary fat you have already eaten from being absorbed by your body. This helps reduce calorie intake and may improve cholesterol levels too. The only medically approved OTC diet pill in the UK is a fat binder called Alli. This contains a pharmaceutical drug called Orlistat, which many people have used successfully.

Despite the medical endorsement, fat binders are not suitable for everyone. All clinical testing has been carried out on obese subjects, and weight loss is generally slow. If you can’t or won’t restrict your diet, we can see that a fat binder may help remove some of your excess calories, especially if you usually consume a high-fat diet. However, if fat is not your major food issue, it is unlikely to be effective. By contrast, a fat burner will be suitable for most weight loss issues and diets.

How much weight can you lose with fat binders?

There is no simple answer to this question. Although a fat binder may not get fast results, it can reliably help steady weight loss. It all depends upon how you use this supplement, whether you make dietary changes, and the type of food you usually eat. If you stick to a calorie controlled diet in combination with taking a fat binder, you could drastically reduce your daily calorie count.

Some fat binders claim to reduce daily food intake by as much as 500 calories, so add this to your own efforts and you could lose weight without too much effort. The approved level of weight loss, as recommended by the NHS, is 2lbs a week, so this is the type of target you should be aiming at.

But if you simply take a fat binder in the belief that your fats will automatically be cut from your diet, you are unlikely to lose much weight. You may lose a few pounds over a period of months, but results are unlikely to be earth shattering. For example, the product information for Boots Fat Control advises that you use the supplement for six months. Research into Chitosan, a popular fat binding ingredient, noted that in one clinical trial, participants lost on average only 1lb after taking it for seven months.

Sadly, there is no magic diet pill, so it will not really help you much unless you make dietary changes yourself.

Can you poo fat out?

If you take a fat binder your poo will contain more fat than usual, so yes, you do poo fat out. The way a fat binder works is by ensuring that the fat molecules remain too big to be absorbed by your body, so after that there is really only one place for it to go.

A fat binder does nothing to help remove the fat already stored by your body though. It just removes a proportion of dietary fat from your most recent meal – 30% at most – and by removing it, we mean of course that it is contained in your poo.

Human poo is not generally made up of fat. It is mostly composed of water – up to 75%. The other 25% is solid material, mainly made up of bacteria, both living and dead. Fat makes up between 2% and 15% of this remaining quarter, and is composed of dietary fat and bacteria in the form of fatty acids.

So even if you take a fat binder, your stools do not actually contain that much fat; it is still mainly water.

Testing on Litramine has shown that cactus fiber has been shown to significantly promote faecal fat excretion in healthy adults. Alli and the prescription drug Xenical, which both contain Orlistat, are known for causing oily fatty stools, very loose motions, and diarrhoea. All these symptoms are caused by a percentage of dietary fat being blocked by digestive enzymes.

Pooing out fat is the key to how a fat binder works. Just remember that dietary fat only makes up a small percentage of poo, even if you do take a fat binder.

How does fat leave the body when you lose weight?

If you lose weight by going on a diet and increasing exercise, your fat is used as energy for the body. Using up more energy (calories) than you consume in food calories will cause fat to disappear.

The body converts fat to usable energy for the muscles and other tissues through a series of complex metabolic processes. This causes your fat cells to shrink because the stored fat is now providing energy, and the waste products are expelled through sweat, urine, and faeces.

When you eat, your body converts any calories it doesn’t need to use right away into triglycerides. If you consume more calories than you use, these are stored as fat.

The only way that fat can leave the body is via the metabolic process. There are no shortcuts. You have to ensure that your body uses up more calories than you consume.

If you take a fat binder, you will lose some of your dietary fat as waste. Although this can make weight loss easier for some people, a fat binder does not block all fats from being absorbed by your body. In even the best scenarios, a fat binder will only prevent around 27% of dietary fat from being absorbed. This means that the remainder will have to be burned off through exercise and a calorie-restricted diet.

What is Orlistat?

Orlistat is a pharmaceutical drug designed to treat obesity. It is manufactured by Roche and is available only under prescription from your doctor, where it goes under the trade name Xenical.

Part of a class of medications called lipase inhibitors, Orlistat works by stopping digestive enzymes in the pancreas from breaking down some of the fats that you consume, so that they pass through the body unabsorbed in stools. Orlistat contains Lipstatin, an inhibitor of pancreatic lipase (which breaks down fat), and is manufactured from a bacterium called Streptomyces toxytricini.

Orlistat is also available to buy over the counter as Alli. This version of Orlistat is not as strong as Xenical and is manufactured by Smith Glaxo Kline. The product information states that it should only be used by people with a BMI over 28. To use, you take it three times a day, an hour before meals. If you are skipping a meal, or the meal is low in fat, you do not need to take it.

There have been numerous clinical tests on Orlistat that show it can provide modest weight loss results. When used in combination with dietary and lifestyle changes, data from clinical trials taken over a year suggests that you can lose 2-3kg (4.4 – 6.6lbs) more than if not taking the drug. Other benefits may include reduced cholesterol and lower blood pressure.

Orlistat – whether as Xenical or Alli – is known for its side effects. You can minimise these by reducing fat content in your diet, but they may include oily stools, diarrhoea, explosive bowel movements, abdominal pain, and spotting. There have been concerns about Orlistat leading to kidney and liver disease as well.

Fat Binder Reviews

Now we have answered the most commonly asked questions, let’s take a look at some of the fat binder supplements that you can buy.

Proactol Plus

Proactol Plus
Proactol Plus is a fat binder based on a cactus extract called Opuntia ficus-indica. It claims to block 27.4% of all dietary fats, helping you lose up to 2lbs a week. You are advised to take one capsule before each meal.

Opuntia ficus-indica has undergone clinical trials and results have been impressive, with many customers mentioning successful weight loss. But despite the good points, Proactol Plus is not available at the time of writing and there is no information about whether it has been discontinued or temporarily withdrawn.

Even if it is still available, Proactol Plus is expensive. One month’s supply costs £34.95 (approximately $68.95). From the official website, Proactol Plus is covered by a 60-day money-back guarantee, although there are some strings attached.

What we like

  • Proven to block up to 27.4% of dietary fats in your meal
  • Low risk of side effects
What we don’t like

  • Premium supplement – cost may put some consumers off
  • Guarantee guidelines must be followed exactly
  • Very slow weight loss

To find out more about Proactol Plus:


Alli is a very well-known fat binder. It has some medical approval, but weight loss results are modest at best. It contains a pharmaceutical drug called Orlistat, and is basically a less powerful version of a prescription drug called Xenical, but is available to buy without a prescription.

Orlistat is clinically proven to cause modest weight loss, but while Alli looks effective, it is known for a range of unpleasant side effects – mainly around the need for urgent bowel movements and oily, loose stools that contain excessive fats. Customers have reported having “accidents” and being unable to leave the bathroom. Alli oops! Orlistat is also linked with causing liver damage.

You can buy Alli from UK pharmacies, and anyone selling this supplement is supposed to check that the customers have a BMI over 28. We have received reports that this rarely happens though.

Alli costs £50.00 for 84 capsules (one month’s supply), but smaller packages are available. There is no money-back guarantee.

What we like

  • Contains clinically proven ingredient
What we don’t like

  • Weight loss results modest at best
  • Unpleasant and potential serious side effects
  • Expensive

To find out more about Alli:

Boots Fat Control

Boots Fat Control
It probably won’t surprise you to learn that Boots Fat Control is a Boots own brand fat binder. For readers who aren’t from the UK: Boots is a much-loved retail outlet. So this diet pill should be a reputable product.

However, Boots Fat Control does not provide information about what this supplement actually contains. It seems to be based on the cactus extract, Opuntia ficus-indica (prickly pear), which is used in many fat binders and has undergone positive clinical testing.

Boots Fat Control does not work very quickly. According to the product information, you need to take this supplement for at least six months or until you reach your target weight.

If you have a high-fat diet you are advised to take 3-4 capsules after each meal. Although you should use Boots Fat Control in combination with a healthy diet and exercise, the message here is that you can eat as much fat as you want and the supplement will do the rest.

You can buy Boots Fat Control online from Boots Pharmaceuticals or in store. It costs £24.99 for 60 capsules. Use as advised and this is less than one month’s supply.

What we like

  • Trusted and well-known retailer
What we don’t like

  • Could work out expensive
  • Lacks money-back guarantee
  • Lacks full ingredient profile
  • No consumer testimonials

To find out more about Boots Fat Control:


Calorease is a fat binder that claims to block up to 500 calories of dietary fat a day. It contains a compound called FBCx (fat binding complex) – a soluble fibre derived from grain.

This fibre is also known as alpha-cyclodextrin and is used in the food industry as an emulsifier. When a small trial tested FBCx on 41 people, increased weight loss and improved insulin control was noted, without participants making lifestyle changes.

The official website provides a menu of big fattening meals that you can apparently now eat without consequences. However, there are customer complaints about this product.

If you do not consume enough fat to bind, it will cause intestinal upset and flatulence. In addition, many customers have mentioned severe stomach pains, bloating, and diarrhoea as side effects. That said, some customers say that Calorease does work as described.

You can buy Calorease from a range of outlets, including Lucky Vitamin, eBay, and Amazon. It costs around $49.99 for 180 capsules (30-day supply). There is no money-back guarantee.

What we like

  • Supplement looks very safe
  • Unlikely to cause harmful side effects
What we don’t like

  • If you do not each much fat in your diet, this pill will not work
  • Weight loss results are very modest
  • Lot of negative customer feedback

To find out more about Calorease:

Fibo Trim

Fibo Trim
Fibo Trim is a fat binder that contains Chitosan, a fibre made from shellfish skeletons, as the principle ingredient. It comes from Advocare, a multi-level marketing company that used to sell supplements via a range of distributors, but has recently changed their business model to sell directly to consumers.

Chitosan has been tested for fat binding, but results are questionable, with one clinical test suggesting that it would take seven months to lose 1lb of weight. Chitosan is combined here with pysllium husk, a fibre with a laxative effect, and there are other components which may increase bowel movements. Unlike many other fat binders, Fibo Trim may have a slight appetite-reducing effect.

Make sure you avoid Fibo Trim if you are allergic to seafood. It may also cause other side effects including, diarrhoea, unpleasant stools, increased bowel movements, and bloating.

You can no longer buy Fibo Trim via an Advocare distributor. Elsewhere, prices vary, but Fibo Trim generally costs around $37.50 for 60 capsules. This will only last between 6–20 days, so it is expensive. You can buy 180 capsules via Amazon for $43.63 including shipping. No money-back guarantee is available.

What we like

  • Full ingredients profile
  • Advocare are a reputable company
  • Better than many other MLM supplements we have seen
What we don’t like

  • Main ingredients need more clinical testing to prove they work
  • May cause side effects
  • Three capsules per serving means you could be taking as many as nine capsules a day
  • No money-back guarantee

To find out more about Fibo Trim:


Xenitol is an OTC fat binder supplement that you can buy via Amazon. Despite the similarities in the name, it is nothing to do with Xenical, a pharmaceutical fat binder only obtainable by doctor’s prescription.

Made by the US supplements company Nexgen Biolabs, Xenitol contains Chitosan as the main fat binder ingredient. Added components include the powerful laxative cascara sagrada, and Garcinia cambogia, which may help block carbs.

Combining a laxative with a fat binder sounds pretty disastrous to us, and, according to customers, you will need to stay close to a bathroom in case of accidents. Reported side effects include diarrhoea, vomiting, and explosive bowel movements. Many customers have also mentioned abdominal pains and acid reflux.

There is positive feedback on Amazon but, as Nexgen Biolabs are well-known for using fake reviews, not all is convincing. More reliable is the high number of reported side effects left by dissatisfied customers.

Xenitol is expensive, costing $39.99 for 60 capsules (15 day’s use) if you buy from the Nexgen website. Prices are similar on Amazon and Walmart. You are unlikely to get your money back if you are dissatisfied.

What we like

  • There are some positive feedback comments that look genuine
What we don’t like

  • Inadequate ingredients profile
  • High number of fake feedback comments
  • Contains a powerful laxative as a principle ingredient
  • Many reported side effects

To find out more about Xenitol:

XLS Medical Fat Binder

XLS Medical Fat Binder
XLS Medical is a well-known supplement brand across the UK and Europe. The parent company is InQpharm, and XLS Medical Fat Binder is one of the company’s flagship supplements. It is on sale from many pharmacies and supermarkets as well as online outlets.

XLS Medical Fat Binder contains a patented ingredient called Litramine. This is based on prickly pear extract (Opuntia ficus-indica) and has undergone clinical testing. Results show that it blocks up to 27% of dietary fat. It may also reduce bad cholesterol levels by 10% within 14 days. Additional ingredients are vitamins A, D, and E, which will have general health benefits.

Despite all this proof, weight loss results are not impressive. Although this supplement does work, it works so slowly that most customers have reported zero difference between taking it and not taking it.

The product is safe according to the manufacturers, but many customers have mentioned loose stools and feelings of bloating.

XLS Medical Fat Burner is expensive. One month’s supply of 180 capsules costs £59.99 from Boots. However, you can shop around a little for a better price.

What we like

  • Ingredients backed by clinical trials
  • Available from trusted online retailers
What we don’t like

  • Expensive
  • Official website limited information
  • No money-back guarantee
  • Some consumers have reported side effects

To find out more about XLS Medical Fat Binder:

BmiSmart I-Remove

BmiSmart I-Remove
BmiSmart is a weight loss brand launched in 2016 by InQpharm, an international company that also owns the XLS Medical brand. I-Remove is their fat binder product that contains Litramine as the sole ingredient.

Litramine contains Opuntia ficus-indica and gum arabic. This patented formula has undergone clinical testing and results show that it blocks up to 27% of dietary fat. It may also reduce bad cholesterol levels by 10% within 14 days.

I-Remove is very similar to XLS Medical Fat Binder but is aimed at the US market. US customers have not been impressed though. One customer wrote,

If this is the “favorite” weight loss product in Europe then that makes me feel better because it means there are a lot of gullible people there, too, just as there are in the US.

This is an expensive supplement. We found it on sale for $66.49 for 180 tablets (one month’s supply) from Lucky Vitamin. BmiSmart I-Remove does not come with a money-back guarantee.

What we like

  • Unlikely to cause too many side effects
  • May help support weight loss
  • Reputable company and a tested formula
What we don’t like

  • Will not work for everyone
  • Expensive
  • May increase bowel movements and gas

To find out more about BmiSmart I-Remove:

Proactol XS

Proactol XS
Proactol XS is another fat binder that contains Chitosan as the sole ingredient. Unlike most other fat binders on the market, this is derived from fungus rather than shellfish.

Proactol XS is nothing to do with the better-known Proactol Plus, but may attract customers still looking for this once-popular supplement.

The Chitosan in Proactol XS is derived from Aspergillus niger mycelium, a type of mould that affects fruit and vegetables. According to the product information, this ingredient has undergone 40 clinical trials, but we can find no links to this impressive clinical evidence.

We did find one clinical trial carried out on Chitosan derived from fungus. It was conducted in India and suggested a loss of muscle mass as well as fat.

You can only buy Proactol XS from the Bauer Nutrition website, where it costs $49.95 for 60 capsules. Use as recommended and this is only enough for 10 day’s supply.

There is no independent customer feedback available and, although a 60-day guarantee is advertised, the small print states that Bauer will only accept unopened products.

What we like

  • Unlikely to cause major side effects
  • Suitable for vegetarians
What we don’t like

  • The evidence for Chitosan as a fat binder is conflicting
  • Misleading claims in the advertising about clinical testing
  • Unlikely to work as well as claimed

To find out more about Proactol XS:


Fat binders can help generate some weight loss, and many supplements contain proven ingredients that do not cause dangerous side effects. However, we have concerns about fat binders in general. In all cases, weight loss is extremely slow. If you take a fat binder you are generally in for a long haul, and although side effects may not be dangerous, they can be extremely unpleasant.

You can expect increased bowel movements, unpleasant oily poo, and in some cases even experience the odd accident where you can’t reach the toilet in time.

Although a fat binder may help you reduce your daily calorie content by preventing dietary fat from adding to weight, a far simpler option is to change your diet. At best, a fat binder will only block a small percentage of fat – up to 27%. Although this sounds OK, you do need to remember that the remaining 73% of fat will not be blocked.

If you cannot change your diet, and you generally eat a lot of fat, the clinical research suggests that some fat binding ingredients can help reduce weight and cholesterol. If this is you, a supplement that contains Litramine or Orlistat has strong scientific evidence that they work, unlike Chitosan, which really does not.

In our opinion, most people will find it easier to lose weight by reducing fat before eating it, rather than relying on a supplement to take it away.

Check out our guide to the very best diet pills on the market right here.