The nutritional supplement world has seen its fair share of “fat-burning” products claiming to be able to reduce body fat by simply increasing the rate at which fat is oxidized, or burned, within the body. While this approach to a leaner body seems pretty logical, it has one major drawback— as increasing the level of fatty acid oxidation simply results in the production of more of the energy-rich molecule ATP— which, at first glance, may not seem problematic. However, higher levels of ATP do not reduce body fat. In fact, what it will do is trigger homeostatic mechanisms within the body that will simply convert this ATP surplus back into body fat within a rather short period of time. So, the fundamental problem with merely converting body fat into ATP is that this process does not increase the amount of energy expenditure— which is the only valid way to reduce body fat.


There are many different compounds that trigger thermogenesis (the burning of calories induced by heat), with some being much more effective than others. So, after countless hours of scouring through the science, we’ve compiled a list of the top 10 thermogenic supplements that potently increase energy expenditure, giving an uncommon ability to burn fat and keep if off. Green tea extract containing concentrated catechins is not recommended in this review, because of possible liver toxicity!


1. Caffeine Raises Your Thermogenic Buzz

Caffeine is best known as the active ingredient in coffee that stimulates the central nervous system, impeding drowsiness and restoring alertness. Caffeine is also a potent thermogenic compound. In fact, a single dose of 100 milligrams of caffeine can increase thermogenically driven energy expenditure by approximately 100 calories per day2, demonstrating that regularly ingested doses of caffeine can have a significant influence on energy balance and fat loss.


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

P-Synephrine is an alkaloid found in bitter orange and other citrus fruits including oranges and grapefruits3, and is widely used for weight management. Studies show that P-synephrine specifically binds to beta-3 adrenergic receptors found in brown fat.4 This class of adrenergic receptor explicitly activates thermogenesis within brown fat. In line with this finding, P-synephrine has been shown to elicit a thermogenic effect by increasing resting metabolic rate in humans, with no adverse impact on heart rate or blood pressure, which typically occurs by activating the beta-1 and beta-2 adrenergic receptors.5


3. Dopamine Activators: Tyrosine and L-Dopa (from Mucuna pruriens) Drive Thermogenesis

Consumption of the dopamine precursors tyrosine and L-Dopa increases dopamine production and function.6,7,8 The neurotransmitter dopamine regulates neurons that initiate the thermogenic process. In fact, energy expenditure was shown to increase in subjects infused with dopamine in a dose-dependent manner, where greater levels of dopamine increased the amount of energy expenditure.9 Consequently, the capability of tyrosine and L-Dopa to increase dopamine levels should produce a robust thermogenic effect, supporting considerable fat loss.


4. Ursolic Acid Increases BAT Levels for Enhanced Thermogenesis

Another powerful approach that exploits the thermogenic potential of brown fat involves increasing the amount of brown fat in the body. A compound found in many fruits and herbs, known as ursolic acid, has recently been shown to increase brown fat levels.10 Ursolic acid has also been shown to increase the expression of UCP-1, effectively increasing the thermogenic capacity of brown fat. This combined action gives ursolic acid the unique capacity to increase both the activity and quantity of brown fat, providing an extraordinary capacity to increase thermogenically driven energy expenditure and considerable fat loss.
5. Bile Acids Activate Thermogenesis by Stimulating Thyroid Hormone Activity

Bile acids typically emulsify fat for improved digestion. The use of bile acids as a supplement also provides resistance to diet-induced obesity by upregulating thyroid hormone function, which boosts thermogenesis in brown fat.11 More precisely, bile acids have the capacity to bind to the TGR-5 receptor embedded in the cellular membrane of brown fat. The interaction between bile acids and the TGR-5 receptor escalates the expression of the enzyme deiodinase, which catalyzes the production of the active thyroid hormone triiodothyronine or T3. Greater T3 results in the stimulation of UCP-1 production, which enhances brown fat thermogenesis.
6. Kaempferol and 7. Oleuropein – Polyphenols That Improve Thyroid Function and Fat Burning


A wide variety of polyphenolic compounds also enhance thermogenic fat loss. One of the more potent being oleuropein, a polyphenolic found in extra-virgin olive oil, which can enhance noradrenaline secretion and increase UCP-1 in brown fat, triggering thermogenesis.12 Another polyphenolic with remarkable thermogenic properties isolated from different sources such as tea, broccoli and grapefruit is the compound kaempferol. This compound uniquely activates the thermogenic process in muscle cells. All cells have the capacity to burn fat and expend energy via thermogenesis. Kaempferol also stimulates thyroid hormone production, which stimulates thermogenesis in brown fat13, giving kaempferol the unusual capability to activate thermogenesis in different cell types within the body, which most certainly contributes to its robust fat-scorching capacity.
8. Spices: Capsaicin, Piperine, Ginger (Gingerols), Cinnamon (Cinnamaldehyde)

Capsaicin is the spice found in chili peppers that contributes to the hot and spicy flavor of the chili pepper. Capsaicin directly binds and activates the TRPV1 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 thermogenesis14,15, while longer term ingestion of roughly six weeks increased thermogenesis in brown fat, resulting in reduced body fat.16 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 increase the amount of brown fat in the body.


Three more spices— piperine, the spicy compound from black pepper; cinnamaldehyde, the pungent ingredient in cinnamon; and gingerol, the active constituent in ginger— also strongly induce thermogenic fat loss. Like capsaicin, piperine and gingerol activate the TRPV1 receptor while cinnamaldehyde activates the TRPA1 receptor, a member within the TRPV1 family of receptors. Activation of this family of receptors triggers thermogenic energy expenditure in a similar fashion to capsaicinoids17,18, which ultimately depletes body fat in a similarly powerful way. For best results, take quick-release supplements of capsaicin. Coated or delayed-release capsaicin may not be as effective because they bypass TRPV1 receptors in the stomach and upper gastrointestinal tract.


9. Forskolin (from Coleus forskohlii)

Forskolin is a chemical produced by the Indian coleus plant that activates the enzyme adenylyl cyclase within brown fat, resulting in greater cyclic AMP (cAMP) levels. Increased levels of cAMP in brown fat cells also occur when noradrenaline binds to the beta-adrenergic receptor, triggering thermogenesis. Therefore, the ability of forskolin to increase cAMP levels in brown fat also enhances thermogenesis. In fact, it has been reported that hamsters and rats given forskolin increased oxygen consumption and thermogenic activity of brown fat.19 Furthermore, forskolin does not interact with beta-receptors in brown fat cells like noradrenaline does20, indicating that forskolin could have an additive impact on thermogenesis when taken with other thermogenic compounds that directly trigger noradrenaline release and beta-adrenergic production of cAMP— producing superior levels of thermogenic fat loss.


10. Melatonin

Melatonin is a hormone secreted by the pineal gland in the brain that regulates the sleep/wake cycle, helping you fall asleep. Melatonin is also involved in energy metabolism and bodyweight control. Many studies show that melatonin reduces bodyweight and abdominal fat21 without eating less or increasing physical activity. Conceivably, melatonin reduces fat without decreasing food consumption or physical activity by activating thermogenesis in brown fat22, which increases energy expenditure and thus fat loss.




Comments are closed.