Top 10 Thermogenic and Brown Fat Activators

Increase Energy Expenditure – Burn Fat and Keep It Off!

Most weight-loss programs involve caloric restriction combined with some kind of rigorous exercise program. This generates an energy deficit that prompts the body to burn fat in order to replenish energy, which in due course promotes fat loss. In theory, this approach seems very logical and should work well, but it has been rather ineffective at achieving fat loss based on the fairly high levels of obesity seen in the United States.1 Furthermore, the typical fat-burning regimen generally involves extensive cardiovascular work that inhibits muscle growth, especially while cutting calories, making this an ineffective choice for those trying to lose fat while maximizing muscle.

Burn Fat With BAT

In view of the above-mentioned shortcomings, alternate ways to reduce body fat have recently gained considerable interest. One fat-loss target that has emerged as potentially groundbreaking is brown adipose tissue (BAT) or brown fat. BAT normally generates body heat by vigorously burning body fat, by a process known as non-shivering thermogenesis, in response to cold temperature exposure in order to maintain normal body temperature. The ability to burn fat with BAT represents a promising way to improve fat loss.

BAT is composed of a unique type of fat cell that generates a considerable amount of heat, because of its remarkable capacity to uncouple the normally linked process of fat burning with cellular energy (ATP) production within the mitochondria. As a result, instead of the energy from fat being used to synthesize ATP, it is instead converted into heat. To some degree, all cells can generate heat by thermogenesis, especially when body temperature is below a regulatory threshold. However, BAT is the most proficient thermogenic tissue in the body for two basic reasons. First, each cell has a higher number of mitochondria compared to other cells. Second, these mitochondria have a higher-than-normal concentration of a protein known as uncoupling protein 1 (UCP-1) within their mitochondria. UCP-1, as its name implies, is the protein that directly uncouples fat oxidation with ATP production, producing heat instead.

Interestingly, BAT has been long recognized as a thermogenic organ in other species, yet has only recently been found to exist in adult humans. Despite only recently discovering the existence of BAT in adults, there has been an abundance of scientific inquiry into BAT function that has produced a ton of evidence demonstrating that BAT has a significant regulatory function controlling whole-body energy expenditure and body fat levels in adult humans.2-6 Furthermore, additional research has led to the discovery of many naturally occurring compounds that strongly augment BAT-induced fat burning.

Compounds That Trigger Thermogenesis

There are many different compounds that trigger thermogenesis, with some being much more effective than others. This month, we’ve compiled a list of the top 10 thermogenic supplements that based on scientific evidence, potently increase energy expenditure— giving an uncommon ability to burn fat and keep it off. Green tea extract containing concentrated catechins is not recommended, despite its capacity to trigger thermogenesis, because of possible liver toxicity.

1. CAFFEINE Helps Raise Thermogenic Buzz

Caffeine is the active ingredient in coffee that stimulates the central nervous system, so it impedes drowsiness and restores alertness. Caffeine is a potent thermogenic compound. In fact, a single serving of 100 milligrams of caffeine can increase the body’s thermogenically driven energy expenditure by a significant amount of calories per day, suggesting that if caffeine is ingested on a regular basis, it can exert a significant influence on energy balance and fat loss.

 2. P-SYNEPHRINE (from Citrus aurantium) Safely Boosts Thermogenic Fat Loss

P-Synephrine, an alkaloid found naturally in bitter orange and other citrus fruits, including Tarocco and Naveline oranges and grapefruits, has been widely adopted as a useful supplement in bringing about the successful control of bodyweight. Studies have shown that p-synephrine specifically binds to the beta-3 adrenergic receptors found in brown fat. This class of adrenergic receptor specifically activates thermogenesis within brown fat. Inspired by this finding, scientists delved further and found that p-synephrine can elicit thermogenesis, ultimately increasing the resting metabolic rate in humans. Even better is the significant finding that no adverse impact on heart rate or blood pressure occurred during this process. This stands in marked contrast with the negative effects on heart rate and blood pressure that occur when beta-1 and beta-2 adrenergic receptors are activated.


Tyrosine and L-Dopa (from Mucuna pruriens) Drive Thermogenesis

Dopamine production and function within the body are aided with the consumption of the dopamine precursors tyrosine and L-Dopa. Dopamine controls and regulates the neurons that initiate the thermogenic process. In fact, energy expenditure has been shown to increase in subjects infused with dopamine in a dose-dependent manner, where greater levels of dopamine increased the amount of energy expenditure. With this, the capability of tyrosine and L-Dopa to optimize dopamine levels produces a desirable thermogenic effect, which results in fat loss.


Increases BAT Levels for Enhanced Thermogenesis

Another approach that makes use of the thermogenic potential of brown fat is one that is designed to increase the amount of brown fat contained within the body. Ursolic acid, a compound found in many fruits and herbs, has been shown to increase brown fat levels. It also acts as a stimulus for the expression of UCP-1, which effectively increases the thermogenic capacity of brown fat. Taken together, the ability of ursolic acid to bring about these two beneficial processes makes it a key supplement for producing thermogenically driven energy expenditure and considerable fat loss.


Activate Thermogenesis by Stimulating Thyroid Hormone Activity

Bile acids are typically recommended by physicians and allied professionals for their ability to emulsify fat so that the digestive process can be improved. Bile acids, when used as a supplement, also help promote resistance to dietary-induced weight gain/excess weight by their ability to maximize thyroid hormone function, which turns on thermogenesis in brown fat cells. Bile acids have the capacity to bind to the G-protein TGR-5 receptors embedded in the cell membranes of brown fat. The interaction between bile acids and the TGR-5 receptor triggers the expression of the enzyme deiodinase, which acts as a catalyst to increase the production of the active thyroid hormone triiodothyronine (T3). When there are adequate amounts of T3 circulating in the bloodstream, there will be an accompanying enhanced production of UCP-1 in brown fat. And when UCP-1 production is increased, the furnace of brown fat thermogenesis will be ignited.


Polyphenols That Optimize Thyroid Function and Fat Burning

There is a wide assortment of polyphenols that have the power to accelerate thermogenic fat loss. Among the more potent members of this group of compounds is oleuropein, which is found naturally in extra-virgin olive oil. Oleuropein has the ability to trigger noradrenaline secretion while concomitantly increasing UCP-1 levels inside the brown fat cell.

Another polyphenolic with remarkable thermogenic properties is kaempferol, which is isolated and extracted from a wide variety of foods such as tea, broccoli and grapefruit. This compound has the ability to activate the thermogenic process in muscle cells. Kaempferol also stimulates thyroid hormone production, which brings about thermogenesis in brown fat. Kaempferol is unique in its ability to activate thermogenesis in different cell types throughout the body, giving it a unique capacity to scorch body fat.


Capsaicin, Piperine, Ginger (Gingerols), Cinnamon (Cinnamaldehyde)

Capsaicin is the ingredient found in chili peppers that contributes to the hot and spicy flavor of the chili pepper. Capsaicin directly binds and activates the TRPV-1 receptor within the oral cavity— which releases noradrenaline, boosting thermogenesis in brown fat. Several studies have shown that a single ingestion of capsaicin can activate brown fat thermogenesis, while longer term ingestion of roughly six weeks increased thermogenesis in brown fat, resulting in reduced body fat. Interestingly, this six-week study also showed thermogenic activity in brown fat contributed significantly to fat loss in individuals who had an extremely low amount of brown fat before the study began, which strongly suggests that long-term intake of capsaicin can also help increase the amount of brown fat in the body.

Three more spices— piperine, the spicy compound found in black pepper; cinnamaldehyde, the pungent ingredient in cinnamon; and gingerol, the active constituent in ginger— also strongly induce thermogenic fat loss. As does capsaicin, piperine and gingerol can activate the TRPV-1 receptor, while cinnamaldehyde activates the TRPA-1 receptor, which is a member of the TRPV-1 family of receptors. Activation of these receptor sites triggers thermogenic energy expenditure in a fashion similar to capsaicinoids. These mechanisms can be strong contributors toward accomplishing desired weight loss.

9. FORSKOLIN (from Coleus forskohlii)

Forskolin, a chemical produced by the Indian coleus plant, has the ability to activate the enzyme adenylyl cyclase within brown fat, which results in elevated cyclic adenosine monophosphate (cAMP) levels. Increased levels of cAMP in brown fat cells also result when noradrenaline binds itself to the beta-adrenergic receptor, which then triggers thermogenesis. There is scientific evidence that when hamsters and rats are fed forskolin, there is an increase in oxygen consumption and thermogenic activity in their brown fat cells. An added benefit of forskolin is that, unlike noradrenaline, forskolin has the ability to stimulate thermogenesis without binding to the beta receptors in brown fat cells. This finding indicates that forskolin could have an additive impact on thermogenesis if taken along with other thermogenic compounds that can trigger noradrenaline release and beta-adrenergic receptor production of cAMP— producing an additive thermogenic effect that will conceivably drive superior levels of fat loss.


Melatonin, a hormone secreted in the brain by the pineal gland, is the regulator of the sleep/wake cycle and specifically promotes restful sleep. It is also involved in energy metabolism and bodyweight control. Scientific studies have demonstrated melatonin’s ability to promote the reduction of bodyweight and abdominal fat (even controlling food consumption). The likely mode of action of melatonin involves its ability to activate thermogenesis in brown fat, with a subsequent increase in energy expenditure that drives the accompanying fat loss.


Green Tea Extract With Concentrated EGCG Not Recommended

Green tea extract is an extremely popular supplement that people take to promote weight loss. The active ingredients in green tea include caffeine and epigallocatechin gallate (EGCG). Green tea extract appears to have few side effects other than elevated heart rate and small increases in blood pressure, but research indicates that green tea extract can be toxic to the liver and has no long-term effects on body composition.

Epigallocatechin gallate (EGCG) is a polyphenol found in green tea extract. A study on mice from China and Rutgers University found that EGCG was toxic to the liver by reducing important antioxidants that protect it from free radical damage. Free radicals are highly reactive chemicals linked to cell membrane damage, destruction of DNA and cell death.

A study led by Herbert Bonkovsky at the Wake Forest University School of Medicine reported that EGCG is toxic to the liver when taken in high doses. Researchers reported that at least 20 cases of liver injury have stemmed from green tea extract supplements. They stated, however, that these findings do not apply to consumption of green tea because the EGCG levels do not approach those found in green tea extract supplements.

We are in the dark about the dangers of herbal products such as green tea extract. While people from China have consumed green tea for centuries, it is only recently that we have been able to concentrate key ingredients in herbal products such as EGCG, promoting the consumption of higher dosages that may lead to adverse side effects.

Another study linked the consumption of green tea extract to liver cancer. Catechins are a second group antioxidants also found in green tea. In a study of more than 18,000 men, Lesley Butler and colleagues, from the University of Pittsburgh Cancer Institute, found that high levels of catechins were linked to markers of liver cancer in people who were prone toward the disease. Blood catechins increase in direct proportion to their consumption in the diet. Taking high doses of green tea extract could be deadly in high-risk people. The researchers noted that the incidence of liver cancer was much higher in China than in the United States as green tea is a staple of the Chinese diet.

High intake of green tea and green tea extract might be toxic to the liver. In one of the first case reports associating hepatitis with the consumption of brewable green tea, a healthy 16-year-old girl in England developed acute hepatitis after drinking three cups per day of Chinese brewable green tea, purchased online, for three months. After the consumption of green tea was stopped, there was a rapid and sustained recovery from hepatitis.

Other research found that green tea has no long-term effects on body composition. A 12-week study of 60 young adult men and women showed that it had no effect on fat absorption, resting energy expenditure and body composition. By itself, EGCG is not effective for increasing weight loss.

New reports are emerging that describe mechanisms or conditions involved in possible liver damage as well as continuing cases of “drug-induced liver injury” occurring in people using EGCG-containing products. There are many reports that support both the idea that consumption of a great amount of EGCG can induce hepatocellular toxicity (liver damage) and that certain common drugs and supplements may exacerbate this. The limited benefit of green tea extracts for weight loss does not appear to be worth the risk. Therefore, green tea extract containing concentrated EGCG is not recommended because of possible liver toxicity.

For more information about compounds that trigger thermogenesis, including the latest research, as well as green tea and liver toxicity, see the Thermo Heat™ Weight Loss Revolution available at

Follow Advanced Molecular Labs On:

Facebook: Advanced Molecular Labs

Twitter: @AML_Nutrition

Instagram: @advancedmolecularlabs


1. Haslam, D. Obesity: a medical history. Obes Rev 8 Suppl 2007;1, 31-36.
2. Nedergaard J, Bengtsson T and Cannon B. Unexpected evidence for active brown adipose tissue in adult humans. Am J Physiol Endocrinol Metab 2007;293, E444-452.
3. Saito M, Okamatsu-Ogura Y, et al. High incidence of metabolically active brown adipose tissue in healthy adult humans: effects of cold exposure and adiposity. Diabetes 2009;58, 1526-1531.
4. van Marken Lichtenbelt WD, Vanhommerig JW, et al. Cold-activated brown adipose tissue in healthy men. N Engl J Med 2009;360, 1500-1508.
5. Virtanen KA, Lidell ME, et al. Functional brown adipose tissue in healthy adults. N Engl J Med 2009;360, 1518-1525.
6. Cypess AM, Lehman S, et al. Identification and importance of brown adipose tissue in adult humans. N Engl J Med 2009;360, 1509-1517.