Fat Burner Ingredients Review

There are a number of different fat burners out there and they use a variety of ingredients. Understanding what each ingredient does is important to choose the most effective and safest product. After reviewing a number of fat burner ingredients that different products contain and investigating the evidence behind their effectiveness, I’ve come up with a list of the best fat burner ingredients. The list contains those ingredients that are not only effective in reducing body fat but are safe at the same time.

I’ve also come up with a list of fat burner ingredients that may work, but there may be insufficient evidence behind them or not enough research on their side effects. Last, but not least, I’ve created a list of fat burner ingredients to avoid based on known side effects or ineffectiveness.

– Top-rated natural fat burners –

Safe Fat Burner Ingredients that Work

#1 Green Tea Extract

Green tea is consumed widely around the world and has been used as an alternative medicine for thousands of years around Asia. A number of health claims have been made in recent years, claiming green tea to be effective in treating a number of health conditions from cancer prevention to lowering blood pressure through aiding weight loss.

Black, white and green tea all originate from the same plant, Camellia sinensis. The source may be the same, but the processing method is different. The processing of both black tea and green tea involves a fermentation process where the leaves are oxidised.

However, fermentation is a lot shorter in the case of green tea processing. This is the reason why green tea retains more antioxidants and polyphenols than black tea, giving its beneficial properties.

A number of studies have investigated its effectiveness as a fat burner. Research conducted in 2013 has found that subjects taking green tea achieved reduced body fat during the study and the reduction in body fat was even more significant when combined with exercise1.

Green tea is one of the safest, proven natural fat burner ingredients out there.

#2 Glucomannan

Glucomannan is a natural, water-soluble dietary fiber derived from the root of the konjac plant, also known as elephant yam. It has been used in various products due to a number of its beneficial properties.

Amongst its many uses, glucomannan appears in a number of food products. It is also used for relieving constipation, lowering cholesterol and aiding weight loss.

A number of studies have investigated its effectiveness in reducing body weight and the way it achieves this. Glucomannan works by absorbing water, causing it to swell up in the stomach and increase the sense of feeling full, therefore reducing food intake.

Glucomannan is a well-researched dietary fiber and its effectiveness as an appetite suppressant has been proven2, 3.

#3 Cayenne Pepper

Cayenne pepper, also known as Guinea spice got its name from the city of Cayenne in French Guiana in South America where it originates from. Cayenne pepper is a hot chili pepper widely used as a spice flavoring dishes all around the world.

In addition to this, it has also been used as an alternative medicine relieving pain and has been used in weight loss products. Cayenne peppers are high in antioxidants and are rich in capsaicin which is the key compound when it comes to weight loss.

Cayenne Pepper
Capsaicin acts in two ways to aid in losing weight. In a 2009 study published by Clinical Nutrition, researchers found that participants of the study consuming a combination of capsaicin and green tea experienced reduced appetite and as an effect reduced their food intake4. Another 2009 research published by the European Journal of Nutrition suggested that capsaicin’s effectiveness in reducing appetite may be due to its ability to lower the level of a hormone called ghrelin which is responsible for alerting our body when we feel hungry5.

Further studies have suggested that beyond its appetite suppressing properties, capsaicin is also a thermogenic agent helping the body to speed up its metabolism which results in burning more fat naturally6. Taking fat burners containing cayenne pepper extract is not going to be like eating spicy food. You won’t be able to taste the spice as it goes straight to your stomach.

#4 Caffeine

Caffeine is a naturally occurring stimulant that can be found in coffee beans, tea leaves and cocoa seeds. Due to its beneficial properties, it is also an additive to a number of other products such as energy drinks, painkillers and fat burners.


Caffeine is a well-researched stimulant and studies have shown that it increases endurance and resistance to fatigue. Therefore, giving you an energy boost when you train, so you can train for longer7.

What’s more, studies have also found that caffeine also helps the body to burn the fat stores instead of just burning the stores of carbohydrates8. It achieves this through thermogenesis, speeding up the body’s own metabolic rate. Caffeine Anhydrous is the most used form of caffeine in fat burners.

To achieve fat loss it is important to use fat burners that contain a sufficient amount of caffeine. Look for products that contain around 200-300 mg of caffeine in a daily serving. High amounts of caffeine can cause unwanted side effects.

#5 Green Coffee Beans

Green coffee beans are unroasted coffee beans. They contain a chemical called chlorogenic acid that has been linked to a number of different health benefits one of which is weight loss.

During the roasting process, the amount of chlorogenic acid in the beans is reduced. Therefore, your regular cup of coffee made of roasted coffee beans contains a lot less chlorogenic acid than green coffee beans.

Human studies have shown promising results of chlorogenic acid’s ability to reduce absorption of carbohydrates resulting in weight loss9.

Green Coffee

– Read about my top-rated natural fat burners that contain these ingredients –

top rated natural fat burners

Fat Burner Ingredients that May Work

#1 White Kidney Bean Extract

This ingredient is regarded as a carbohydrate-blocker. As the name says, it blocks the digestion of starches. It achieves this by blocking the activity of the digestive enzyme, alpha amylase.

A few human studies showed that participants taking white kidney bean extract had reduced their body mass and more importantly their body fat10.

The studies showing positive results used daily doses of over 400 mg.

However, as white kidney bean extract works by stopping the absorption of some of the carbohydrates consumed, it can also stop vitamins, nutrients, minerals or antioxidants from being absorbed.

#2 L-Carnitine

Some fat burners use L-carnitine as one of their main ingredients. It is an amino acid that is naturally produced in the body and it can be found in some food like meat, fish and milk.

A study from 2011 found supporting evidence that combined with low-intensity exercise, L-carnitine helps to reduce the body’s consumption of carbohydrates and instead uses more of the body’s fat stores to turn into energy11. However, the effects of L-carnitine seem to depend on the intensity of the exercise.

Despite this research, there is still very little evidence of L-carnitine being an effective fat burner and there is a lack of research into the side effects of L-carnitine when combined with stimulants such as caffeine or green tea.

#3 Guarana

Some fat burner supplements have chosen Guarana as one of their key ingredients to increase metabolism and burn body fat faster. It is derived from the seeds of a plant native to the Amazon basin in South America.

Guarana is a stimulant and the seeds contain about twice the amount of caffeine than in coffee beans. It has been used in fat burners due to its high caffeine content. However, most of these studies are only small scale or have found contradicting results when it comes to its effectiveness12. Also, there is limited research about its potential long-term side effects.

#4 Raspberry Ketones

Raspberry Ketones, also known as Rheosmin became increasingly popular as a fat burner ingredient in recent years. It is a natural compound that gives raspberries their distinctive aroma. Other than raspberries, cranberries and blackberries also contain some Raspberry Ketones. It is used in cosmetics and as a food additive due to its fruity aroma.

Up until recent years, it has mainly been used by the cosmetics and food industry. However, this has changed after its increased popularity as a fat burner ingredient. Some research conducted on rats has shown promising signs of raspberry ketones helping the body break down fat.

These are great initial results. However, to date, I haven’t found human studies that could support the claims made by supplement manufacturers in relation to raspberry ketones. Also due to the lack of research on people, there is still little known about the potential side effects of raspberry ketones.

#5 Salicin

Salicin is a chemical found in willow bark of willow trees. When the body processes salicin, it turns it into something called salicylic acid, which is the chemical precursor to aspirin. There has been a number of studies looking at the pain relieving properties of salicin, but there is lack of research concentrating on its weight loss properties.

There are studies that researched the effects of salicin in combination with other fat burner ingredients such as caffeine, synephrine, and the now banned ephedrine, but the results of these studies don’t show the effects of salicin as a stand-alone ingredient.

These studies may have found evidence that a combination of these ingredients helped individuals to lose weight, but they did not prove that salicin on its own has a positive impact on weight loss.

As it has similar pain relief effects to that of aspirin, it can also produce similar side effects if it’s taken in high doses for long periods of time. It may not be safe to take for people who use blood thinners, have sensitivities or allergies to aspirin, have bleeding disorders or kidney disease.

#6 Garcinia Cambogia

There has been a lot of hype around Garcinia Cambogia in recent years. Companies have been making great weight loss claims about it, but is there any evidence behind these claims? Garcinia Cambogia is derived from a tropical plant of the same name.

It claims to work in two ways assisting weight loss. Allegedly, it curbs appetite and also inhibits fat production in the body. The active ingredient in Garcinia Cambogia is Hydroxycitric Acid (HCA).

Some evidence suggests that Garcinia Cambogia can elevate serotonin levels in the body which in turn also decreases appetite. A 2008 human study found no dietary efficacy of Garcinia Cambogia (Journal of Clinical Biochemistry and Nutrition, Yonei et al.)13.

In addition to this, a 2011 study investigating the effectiveness of Garcinia Cambogia found that Garcinia Cambogia can cause a small amount of weight loss short-term (Journal of Obesity, Onakpoya et al.)14.

It seems that Garcinia Cambogia may have some weight loss properties. However, the evidence certainly does not support claims of it being a miracle product when it comes to weight loss. There is need for further research in terms of its side effects. Due to its ability to elevate serotonin levels, it can cause potential problems when people are taking it with certain antidepressant drugs.

Fat Burner Ingredients to Avoid

#1 “Proprietary Blend”

A number of supplements including fat burners hide their ingredients behind a so-called proprietary blend. What this means is, that you won’t know exactly what you are taking. This can pose serious health risks if the product contains ingredients that you may be sensitive or allergic to.

Not knowing what ingredients a supplement contains means that you won’t know whether the product is effective or not. So when it comes to “proprietary blend”, our advice is to avoid.

#2 Bitter Orange

The FDA (Food and Drug Administration) banned Ephedra due to the health problems it causes. Following this, bitter orange has gained popularity amongst weight-loss supplement manufacturers as one of the key fat burner ingredients.

Bitter orange is a natural ingredient, but that doesn’t mean that it is safe. It contains synephrine and octopamine, compounds which have similar effects to that of ephedra. Bitter orange can raise blood pressure and speed up heart rate. People taking bitter orange on its own or with other stimulants reported stroke and heart attack.

Due to the health risks it potentially poses bitter orange is one of the fat burner ingredients to avoid.

#3 Synephrine

Synephrine is a compound of bitter orange. It has similar effects to that of ephedra, an ingredient previously banned by the FDA due to potential health risks.

Some studies have found evidence that synephrine increases metabolic rate in individuals and can, therefore, aid weight loss. Despite some supportive research, there is still a lack of evidence that synephrine is effective in maintaining weight loss.

On the other hand, there is research evidence out there that shows the potential side effects of synephrine. It can raise blood pressure and speed up heart rate. People taking synephrine combined with other stimulants such as caffeine have reported stroke and heart attack.

Read about what to avoid when you are looking for a natural fat burner
– Top-rated natural fat burners –


1. Cardoso, G. A., Cesar, Mde C., Donado-Pestana, C. M. and Salgado, J.M. (2013). The effects of green tea consumption and resistance training on body composition and resting metabolic rate in overweight or obese women. Journal of Medicinal Food, Vol. 16, Issue 2, pp. 171-178.

2. Behforooz, A., Walsh, D.E. and Yaghoubian, V. (1984). Effect of glucomannan on obese patients: a clinical study. International Journal of Obesity, Vol. 8, Issue 4.

3. Keithley, J. and Swanson, B. (2005). Glucomannan and obesity: a critical review. Alternative Therapies in Health and Medicine, Vol. 11, Issue 6, pp. 30-34.

4. Martinussen, T., Møller, P., Reinbach, H.C., Smeets, A. J. and Westerterp-Plantenga, M. S. (2009). Effects of capsaicin, green tea and CH-19 sweet pepper on appetite and energy intake in humans in negative and positive energy balance. Clinical Nutrition, Vol. 28, Issue 3, pp. 260-265.

5. Smeets, A. J. and Westerterp-Plantenga, M. S. (2009). The acute effects of a lunch containing capsaicin on energy and substrate utilisation, hormones, and satiety. European Journal of Nutrition, Vol. 48, Issue 4, pp. 229-234.

6. Hursel, R., Janssens, P. L. H. R., Martens, E. A. P. and Westerterp-Plantenga, M. S. (2013). Acute Effects of Capsaicin on Energy Expenditure and Fat Oxidation in Negative Energy Balance. PLOS One, Vol. 8, Issue 7.

7. Graham, T. G. (2001). Caffeine and Exercise: Metabolism, Endurance and Performance. Sports Medicine, Vol. 31, Issue 11, pp. 785–807.

8. Wilcox, A. R. (1982). The effects of caffeine and exercise on body weight, fat-pad weight, and fat-cell size. Medicine and Science in Sports and Exercise, Vol. 14, Issue 4, pp. 317-321.

9. Thom, E. (2007). The effect of chlorogenic acid enriched coffee on glucose absorption in healthy volunteers and its effect on body mass when used long-term in overweight and obese people. The Journal of International Medical Research, Vol. 35, Issue 6, pp. 900-908.

10. Barrett, M. L. and Udani, J. K. (2011).
A proprietary alpha-amylase inhibitor from white bean (Phaseolus vulgaris): A review of clinical studies on weight loss and glycemic control. Nutrition Journal, Vol. 10

11. Constantin-Teodosiu, D., Greenhaff, P. L., Macdonald, I. A., Marimuthu, K., Stephens, F. B. and Wall, B. T. (2011).
Chronic oral ingestion of l‐carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. The Journal of Physiology

12. Boozer, C. N., Chen, G., Heymsfield, S. B., Nasser, J. A., Solomon, J. L. and Wang, V. (2001). An herbal supplement containing Ma Huang-Guarana for weight loss: a randomized, double-blind trial. International Journal of Obesity and Related Metabolic Disorders, Vol. 25, Issue 3, pp. 316-324. 

13. Hibino, S., Takahashi, Y., Watanabe, M., Yonei, Y. and Yoshioka, T. (2008). Effects on the Human Body of a Dietary Supplement Containing L-Carnitine and Garcinia cambogia Extract: A Study using Double-blind Tests. Journal of Clinical Biochemistry and Nutrition, Vol. 42, Issue 2.

14. Ernst, E., Kang Hung, S., Onakpoya, I., Perry, R. and Wider, B. (2011). The Use of Garcinia Extract (Hydroxycitric Acid) as a Weight loss Supplement: A Systematic Review and Meta-Analysis of Randomised Clinical Trials. Journal of Obesity.