Protein World Fat Metaboliser

Many of us realise that supplements are not always totally useful or trustworthy. Despite this, we normally maintain faith that the product labels and ingredients lists we see at least state accurate information. What should we do when we hear that a manufacturer misrepresents or lies about this vital information?

Below we take an in-depth look into Fat Metaboliser, to see whether this Protein World weight loss pill suffers from the same shocking problems that have been found in other Protein World products.

Protein World Fat Metaboliser Pros

  • Product is not particularly expensive
  • Widely available for purchase in the UK

Protein World Fat Metaboliser Cons

  • Manufacturer has a history of false advertising and lying about ingredient quantities
  • Strong potential for side effects
  • No money back guarantee
  • Customer reviews are generally negative
Watchdog Rejected

Protein World Fat Metaboliser

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What You Need To Know About Protein World Fat Metaboliser

Protein World Fat Metaboliser is a simple stimulant-based weight loss product. The formula works through a hefty dose of caffeine, that is intended to act as a thermogenic fat burner and metabolism booster. This product is only available to buy in the UK, although international customers may be able to pick up a pack if they are willing to pay substantial shipping and customs charges.

Fat Metaboliser is produced and sold by Protein World, a supplement and diet shake manufacturer based in Surrey, England. Protein World have been embroiled in controversy for several years now, and have been the recipient of numerous investigations and negative attention from national newspapers and regulatory bodies. The company has been accused of brutal “fat-shaming” adverts, and of outright lying about ingredient quantities and product benefits. The company has defended its advertising practices as “highly effective” in media statements.

What Are The Side Effects Of Protein World Fat Metaboliser?

Fat Metaboliser contains a very high dose of caffeine, which can cause side effects even for those who aren’t particularly sensitive to caffeine (especially if customers continue consuming coffee or energy drinks whilst taking the product). Expect issues related to jitters, sleeplessness, increased heart rate, increased blood pressure, and dehydration.

To further boost energy, this mix contains doses of Vitamin B6 and B12 that are well in excess of what is recommended. This can cause stomach problems, vomiting, loss of appetite, headaches, a tingling sensation in the skin, drowsiness, and even nerve and brain problems.

How Much Does Protein World Fat Metaboliser Cost?

A 90-capsule pack of Protein World Fat Metaboliser costs £21.99 in most online stores (including Amazon, Superdrug, Argos, Lloyds Pharmacy, and the Protein World webstore). We were able to find a slightly lower price on, where the same pack costs just £18.

Our Verdict On Protein World Fat Metaboliser

Protein World is not known as a reliable manufacturer, and their previous history of lying about ingredient quantities should not be forgotten. As recently as 2016, Protein World was producing packs of diet shakes with up to 17 times more carbohydrates than was claimed on the pack, which likely caused weight gain for the affected customers. In our opinion, it’s hard to see how this could have been a mistake!

Even with this in mind, Fat Metaboliser is a pretty terrible weight loss product. It essentially works by overloading customers with caffeine in the hope of boosting the metabolism, a technique that is not known to be particularly effective (and will also result in a range of unpleasant side effects). Customer reviews are highly negative, with many claiming that the product did little to nothing to aid with weight loss.

For products that work better, are protected by a money back guarantee, and are offered by a more reputable manufacturer, we suggest looking elsewhere!

We would not recommend Protein World Fat Metaboliser to our readers.

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Protein World Fat Metaboliser Review

Protein World Fat Metaboliser is a thermogenic fat burner, produced for customers in the UK. The product contains a notably high dose of caffeine, which has supposedly been included in the formula in order to boost the metabolism.

Protein World Fat Metaboliser Facts

  • Manufactured by Protein World
  • Contains 90 capsules per pack
  • Weight loss supplement with thermogenic action

Fat Metaboliser is manufactured by Protein World, a UK-based supplement and diet shake company. Despite a strong media presence and celebrity backing, Protein World has come under significant criticism for its extremely poor advertising and quality control standards.

How to Take Protein World Fat Metaboliser

The directions for use are as follows:

Take 1-2 of these Fat Metabolising capsules in the morning & again at lunch and beat the day

In May 2016, a British newspaper, the Sun, decided to have Protein World’s flagship product, Slender Blend, tested for quality. Shockingly, it was found that the powders contained a significantly higher amount of carbohydrates than the product’s label stated. The tests found that the chocolate flavour version contained 41 grams of carbohydrates per 100g (the product’s label stated that it contains only 21 grams of carbs per 100 grams). Since the allegations, the company has been investigated by the Surrey Trading Standards agency and the UK’s Advertising Standards Agency, which seems to have generated enough pressure to force Protein World to somewhat amend their practices. The company can be contacted via the details supplied on their official website.

Protein World Fat Metaboliser Concerns:

  • Manufacturer has a reputation for misleading labelling and poor quality control
  • No money back guarantee
  • Product contains a high dose of caffeine that may cause side effects

What Does Protein World Fat Metaboliser Claim To Do?

Perhaps due to their history of trouble with regulatory bodies, Protein World take care to make very few direct claims about their product. On the official website, Protein World don’t even claim that the product can help you lose weight, instead simply mentioning that it contains a high dose of caffeine.

On the Amazon product page, Fat Metaboliser is said to increase the rate at which fat is burned for energy. The caffeine is also said to give a boost of energy, as well as raise the body’s temperature and metabolism for further fat burning. Customers are also told to expect a helpful serving of antioxidants, courtesy of the green tea.

Does Protein World Fat Metaboliser Work?

For the most part, Fat Metaboliser works almost entirely through the use of caffeine and energy-boosting B vitamins. Although stimulant ingredients are known to slightly boost the metabolism, these effects are slight and come at the cost of jitters and other unpleasant side effects. The product also uses useful ingredients like green tea or cayenne pepper, which should work with the caffeine to boost metabolism.

Although this product should work in theory, customer reviews unfortunately paint a very different picture. Most reviews are generally negative, with many suggesting that the product is highly ineffective although still likely to cause negative side effects. Given the manufacturer’s poor reputation for quality control, it’s fair to assume that Fat Metaboliser doesn’t work all too well.

What Are The Ingredients of Protein World Fat Metaboliser?

The ingredients included in Protein World Fat Metaboliser are listed below. Readers should note that the ingredient quantities listed below are correct for 2 capsules of Fat Metaboliser.

  • Vitamin B6 5.6mg: Vitamin B6 has several important functions in the body, including ‘allowing the body to use and store energy from protein and carbohydrates in food’. Whilst taking excess amounts of vitamin B6 will not infinitely improve this ability, a deficiency could make it more difficult to lose weight. Vitamin B6 is naturally present in a wide variety of foods, including meat, cereals, bread, and vegetables. The quantity of Vitamin B6 included in this mix is notably high. Source
  • Vitamin B12 25µg: Vitamin B12 is naturally present in many foods, primarily meat, fish, and dairy products. It has several roles, including aiding in releasing energy from consumed food, and keeping the nervous system healthy. It may be that a deficiency hinders weight loss, but taking excessive amounts could be harmful (as in this product, which contains 500% of your RDA per pack). Source
  • Caffeine Anhydrous 200mg: Numerous studies have shown that caffeine boosts energy levels and alertness, as well as mildly boosting the metabolism, causing a small increase in the number of calories used by the body. The effects shown in studies are small, and some studies are inconclusive. Source
  • Green Tea Extract (40% Polyphenols) 200mg: Green tea is high in a group of antioxidants called catechins. Studies have suggested that catechins and caffeine both increase energy expenditure, by boosting the metabolism temporarily. However, the metabolic increase caused by green tea is limited. One study found that the use of green tea was not enough to counteract weight gain following a high calorie diet. Source
  • L Tyrosine 200mg: An amino acid that is a building block of protein, this ingredient is found naturally in many foods including meat and dairy products. Some people use it as an appetite suppressant, but there is little evidence that it is effective for this use. Large doses of tyrosine may be useful for increasing alertness, especially in people who are sleep deprived. Source
  • Guarana Extract (22% Caffeine) 150mg: A berry that is naturally high in caffeine, Guarana is often an ingredient in energy drinks and diet pills. Studies are mixed as to whether it improves mental performance. Source
  • Yerba Mate Powder 100mg: A plant that is typically brewed as a tea, yerba mate is a natural source of caffeine, and has been the subject of several studies on weight loss. Its high caffeine content could mean that it helps boost mental performance. Source
  • Choline 100mg: Athletes sometimes supplement Choline to delay fatigue and improve endurance. It is also said to improve mental focus. However, the available clinical evidence suggests that Choline does not cause either effect to take place. Source
  • Alpha Lipoic Acid 100mg: Appears to suppress the appetite by inhibiting AMPK in the hypothalamus, although little research has been conducted in humans at this point. This fatty acid also appears to boost fat burning slightly, although the effects are not as large as the noted suppression of appetite. Source
  • Cayenne Powder 50mg: Capsaicin, which is found in Cayenne pepper, is thought by some to play a role in weight loss. Some studies suggest it could suppress the appetite mildly, whilst others suggest that the heat causes a thermogenic reaction in the body, burning more calories for a period of time. However, there are also studies that show cayenne has little or no effect upon weight loss attempts. Source

Does Protein World Fat Metaboliser Have Any Side Effects?

Fat Metaboliser uses a notably high dose of caffeine, which could cause a range of side effects.

High doses of caffeine can cause headaches, jitteriness, insomnia, an increased heart rate, heart palpitations, increased urination, dehydration, and increased blood pressure. Customers that are extra sensitive to caffeine should consider avoiding it altogether, or at least avoid other sources of caffeine whilst using it. The worst effects can be avoided by keeping yourself hydrated, and avoid taking the capsules in the evening.

Medical advice typically recommends avoiding taking more than 500mg of caffeine per days. Two capsules of Caffeine Power contain 200mg of caffeine, as well as other ingredients that are known to be rich in caffeine themselves (including yerba mate, green tea, and guarana).

The energy boosting mix also contains very high levels of Vitamin B6 and B12, which can cause vomiting, stomach upset, loss of appetite, headaches, drowsiness, and a tingling feeling. Long-term high doses of Vitamin B6 can also cause nerve and brain problems; customers should be aware of this, as Fat Metaboliser contains 400% of the RDA for Vitamin B6 per serving!

Not intended for use by persons under the age of 18. Keep out of reach of children. If you are pregnant or breast feeding, consult your health care professional before using this product. People with known medical conditions and/or taking drugs should consult with a licensed physician prior to taking.

Are There Any Customer Reviews For Protein World Fat Metaboliser?

The available customer review we found for Protein World Fat Metaboliser have been generally negative, with most customers reporting that the product did little or caused side effects. Even positive reviews tend to highlight their own positive behaviours and lifestyles, which leaves us with the impression that the product does very little at all.

I have been using these for 2 weeks & in that time I have noticed & suppressed appetite, a more focussed mood & an increased level of energy which is a great advantage when working out 4 times a week & having an active job role! I would say that you need to work out the right balance of lifestyle & a ‘healthy’ diet specific to you as these are a great booster but don’t rely on supplements if you don’t understand how to maintain your weight goals, eating well & a balanced lifestyle!

Hard to tell with these things how long before you see effects. Will be getting another packet to give it a good month trial

Didn’t see any change, won’t buy again.

First week only taking one in the morning and one in the afternoon was ok and seemed to be doing the trick however it tells you to up the does the second week to 2 in the morning 2 in the afternoon. This did not work for me, made me really light headed and bloated. I had to stop taking them

Does Protein World Fat Metaboliser Offer a Money-Back Guarantee?

Protein World do not offer a money back guarantee. Customers may return products within 14 days of receiving them (although the company confusingly mentions several different returns periods within the same paragraph, ranging from 14 to 28 days). In any case, customers are unable to claim a refund if the package is opened. To arrange a refund on an unopened package, customers must email the company to receive a returns form, and must cover the costs of returning it themselves.

Where Can I Buy Protein World Fat Metaboliser?

Protein World Fat Metaboliser is available to buy online on the official Protein World website and Amazon, and should be available online and in-stores at Superdrug, Argos, Lloyds Pharmacy, and Tesco. This product is only available to buy in the UK for the most part, although international customers may be able to arrange international shipping to have it delivered to their home country (always be sure to check shipping prices and customs duties however).

The price of Fat Metaboliser is the same from almost all outlets, costing £21.99 for a pack of 90 capsules. We were able to find a slightly lower price on, where the same pack costs just £18.

How does Protein World Fat Metaboliser compare to Phentaslim?

Criteria Protein World Fat Metaboliser Comparison Phentaslim comparison
Clinically Proven Ingredients
Side Effect Free
Positive Customer Reviews
24/7 Support
Money-back Guarantee

The Diet Pills Watchdog does not recommend Protein World Fat Metaboliser.

Protein World Fat Metaboliser

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Disclaimer: Our reviews and investigations are based on extensive research from the information publicly available to us and consumers at the time of first publishing the post. Information is based on our personal opinion and whilst we endeavour to ensure information is up-to-date, manufacturers do from time to time change their products and future research may disagree with our findings. If you feel any of the information is inaccurate, please contact us and we will review the information provided.

Have Your Say

1 comment on 'Protein World Fat Metaboliser'

  1. I have bought 2 jars of FAT METABOLISER capsules from Boots chemist… Howerver the second jar had a very distinct colour difference… should I be concerned by this?

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