5 Fat Burners That Work - Ingredients and Supporting Clinical Research

There are a lot of misconceptions regarding fat burners and weight loss supplements. This article aims to objectively illuminate the best fat burning ingredients that actually work. No biased claims. No puffery. No bro-science.

This article focuses on supplements, but supplements alone are not the key to fitness and burning fat. Exercise and a healthy diet are still a must if you are going to see significant results. That being said, certain supplement ingredients have been proven to be effective in increasing basal metabolic rate and curbing unhealthy appetites. 

Many of these ingredients are used in Transparent Labs’ products, including our PhysiqueSeries Fat Burner and Fat Burner Stim-Free.

The following list highlights the best and most promising supplements/herbs/ingredients based on clinical and peer reviewed studies. Each ingredient has been shown effective in burning fat individually, however, when combined, these ingredient may have enhanced fat burning outcomes.



Forskolin, the main component of the herb coleus forskohlii, is perhaps the most promising fat burner of the decade.

In a 2002 study [1] including six overweight women, participants were given 250 mg Forslean® (a branded form of Coleus Forskohlii standardized to 10% forskolin) twice daily. After 8 weeks, the resulting weight loss was 9.17 pounds (p<.05*) with an average reduction of body fat percentage from 33.63% ± 3.02 to 25.88 ± 4.77 (p<.05). *

Forskolin works by increasing the levels of an enzyme called cAMP (cyclic adenosine monophosphate). cAMP works to promote lipolysis or fat loss within the body, increase thyroid function, as well as improving the effectiveness of other fat burning substances.

Another study [2] including 30 overweight men (n=15, placebo=15) showed a significant decrease in body fat percentage as measured by a DXA (x-ray measuring body fat tool) compared to placebo group. Subjects receiving 250mg Forslean® twice daily saw on average loss of 4.14 ± 4.47 vs .96 ± 1.66% for the placebo group. The resulting significance was p < 0.05.*


*P value represents statistical significance. In these example, the P value shows that the weight loss was due to the forskohlii with greater than 95% certainty. The other 5% represents the possibility of coincidence or chance. (P < 0.05) is generally regarded as sufficient evidence, within the health and science community, to be considered as proof of efficacy.

Forskolin is one of our favorite fat burners and the studies behind it show promising results. When purchasing Forskolin products, make sure it is dosed at clinical levels. Serving size should be 250mg twice daily. We recommend Forslean® as our preferred supplier of Forskolin. Learn more about how forskolin impacts weight loss here.


Green Tea Extract

Green tea is a super food that benefits almost every aspect of the human body. Most commonly consumed as a drink steeped in hot water, green tea, and green tea catechin are also extremely potent (in a good way!) in powdered supplement form. Of the 4 catechins, EGCG works to impact fat loss most.

Proper dosage of Green Tea EGCG 50% is about 300-500mg daily. Transparent Labs PhysiqueSeries contains 400mg of EGCG per daily serving.

In a 2008 study of green tea extract, 60 (30 green tea, 30 placebo) obese subjects were monitored over 12 weeks and received the same food diet. After 8 weeks, the difference of fat loss for the green tea group was 11.24 pounds - statistically significantly (P < 0.05) lower than the placebo. The green tea was shown to effectively increase energy expenditure at rest as well as overall fat oxidation.



Caffeine can be a powerful tool in one's weight loss journey - if it is not overused. For most, caffeine is a daily staple. However, when used in conjunction with other effective fat burners, exercise, and healthy eating, studies show that it can accelerate weight loss over those without caffeine.

If you are a heavy caffeine user, take 3-6 weeks off from caffeine use. This will effectively remove the caffeine from your body and reset your tolerance - making the fat burning effects more potent.

Caffeine has been shown to work to promote weight loss in 4 primary functions.

  • Increased Metabolism - Caffeine stimulates thermogenesis within the body, resulting in increased calorie burning and the production of heat.
  • Appetite Control - For many, especially the caffeine naive, caffeine works to promote a decreased desire to eat.
  • Fat Oxidation - Studies have shown caffeine to increase fat oxidation, resulting in body fat stores being used to create energy… the holy grail of weight loss.
  • Improved Workouts - Caffeine works best when paired with physical activities. In one study, subjects who consumed caffeine increased their running endurance by 44% over those who consumed no caffeine. [3]


Synephrine (aka bitter orange) is another stimulatory fat burning ingredient that actually works.

In a study testing the thermogenic effect of synephrine, subjects receiving 50 mg synephrine exhibited a 65-183 kcal (depending on paired ingredients) increase resting metabolic rate compared to the placebo. There was no reported change in blood pressure or heart rate compared to the control group. [4]

The 3 primary functions of synephrine are similar to caffeine and work to increase metabolic rate (burning more calories), increase lipolysis (the breakdown of fat) and improve appetite control/suppression. Synephrine pairs synergistically with caffeine for increased overall caloric burn.

Overal, studies show synephrine to be safe, having only a small, statistically insignificant, effect on blood pressure and heart rate.



5-HTP is a chemical in the body made from the essential amino acid, tryptophan. It works to increase brain serotonin levels - which has a variety of benefits ranging from anti-depression to addiction recovery.

However, what we LOVE about 5-HTP is its ability to help people lose weight. 5-HTP works to increase the level of food satisfaction - making people feel full longer and reducing unhealthy cravings.

In comparison to the placebo group, subjects who took 5-HTP over 5 weeks lost 2% of their body weight without being on a diet. Subjects who dieted, lost a total of 5%. The placebo group did not lose weight. [5]

Supplementing with 300-500mg 5-HTP daily can be a powerful way to augment your weight loss efforts.


Want a product that includes all of these ingredients AT clinically tested dosages? Check out our PhysiqueSeries line up. If not, these ingredients a-la-carte should still serve you well. 

fat burners that work

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