MMR: Fat-Loss Supplements: What Works and What Doesn’t

Is there a magic pill out there? Did Phil climb a bean stalk to win the Olympia? Bodybuilders are the most loyal supplement users and believers. I’ve heard of bodybuilders taking everything from some peptide made in a kitchen to oil filtered from cow pellets. Bodybuilders want to be Mr. Heath tomorrow, sometimes at risk to their health.

The supplement industry is bursting with fat-loss supplements that not only prey on bodybuilders, but target the millions of overweight people who desire to lose a few pounds between burgers. At least you, as a bodybuilder, realize that hard work in the gym is a crucial component to getting lean. You know that burning fat is going to require some dietary modifications (i.e. calorie restriction, reduced carbohydrates, nutrient timing). You can appreciate the importance of fasted morning cardio and the concept that “sweat is fat crying”.

Dieting does result in metabolic adaptations that may be counterproductive to your goals. As we go into any caloric deficit to burn fat, our bodies try to adjust by slowing down our metabolism and conserving energy. This is where “fat-loss” supplements can be of assistance. We know that there isn’t a magic pill that will let us sit on our asses and eat burgers while getting lean. However, we do have supplements that can augment our diets and improve our metabolism.

Dietary supplements can improve our weight loss objectives through a number of mechanisms.

The main mechanism for enhancing most of these objectives in our bodies is the activation of the sympathetic nervous system (SNS). The SNS is the system that produces adrenalin (Epinephrine) and noradrenaline (Norepinephrine, NE). We all know the power of the SNS when we experience the “fight of flight” response of fear or excitement during a competition. Your heart starts to pound, you get sweaty, and last thing on your mind is food. This is the mechanism that many successful fat-loss supplements try to harness.

One of the most effective supplements of all time was the “ECA Stack”, God rest its soul. ECA stands for Ephedra, Caffeine, and Aspirin. Unfortunately, this very effective and synergistic combination of compounds is no longer legal since the FDA’s crack down on Ephedrine. The premise of the combo was to hit the SNS from multiple angles1. Ephedrine stimulated the release of NE just like exercise and fear. Caffeine and other alkaloids (theobromine, theophylline, etc) prevent the NE signal from being turned off. The aspirin inhibits the formation of prostaglandins that can modulate the action of NE. Other compounds can prevent the breakdown of NE (polyphenols like green tea catechins inhibit COMT) or further turn on the signal from NE on its target tissues like the fat cell, muscle, and heart (Forskolin, Xanthines).

Otherwise, supplements also try to turn on metabolism by specifically “turning up the heat”. Our bodies have a tissue called “brown fat” or Brown Adipose Tissue; BAT for short. BAT is much more metabolically active than the “white adipose tissue” that creates our insulation and spare tires. BAT burns fat to release energy in the form of heat. Many scientists are searching for ways to turn on BAT to improve fat burning metabolism. Fortunately, we can turn on BAT with environmental changes (lower the room temp), food changes (eat more protein) and supplements (Capsaicinoids, melatonin, etc).

Other supplements say they turn on thyroid hormone, reduce conversion of sugars to fats, and decrease the absorption of fats or sugar. In the remainder of this article, I will lay out some data on common and up-incoming fat-loss supplements. As we move forward it is important to understand that research in animals does not always translate to an effect in humans.


Everyone knows what caffeine can do to them. Who hasn’t tried a Starbuck’s coffee? If you’ve ever tried a fat burning supplement, you have likely had some pure caffeine. Caffeine from tea and coffee may provide added benefit from the other active polyphenols that may have fat burning benefits as well (see below). If nature put caffeine and catechin polyphenols in the same package (tea) then why not put them together in a supplement? Caffeine alone or in combination green tea catechins dose-dependently increases energy expenditure and fat oxidation2.

Caffeine may be one of the most studied thermogenic compounds. It stimulates the SNS, controls appetite, mobilizes fats from stores, and increases fat oxidation3,4.  The main problem with caffeine is that we very quickly desensitize to its effects5. Those who regularly drink a Venti coffee are not likely to see its beneficial effects on weight loss. I would suggest that if you want caffeine to work in your favor, limit your exposure to it in the off-season. The chlorogenic acids from green coffee been extract may also provide a fat burning effect, although the jury is still out18.

Green Tea Catechins

As mentioned above, the polyphenols from teas like green tea have powerful effects on fat burning. Catechins in tea inhibit the enzyme catechol O-methyltransferase (COMT) that is present ubiquitously in the body and degrades SNS compounds such as NE4. Through this inhibition of COMT the SNS activity of NE remains activated. Thus, the catechins keep the actions of caffeine and exercise “revving” longer. White tea may even be better than green tea with its higher caffeine and catechin content.

The problem with green tea extracts is when the most active catechin, epigallocatechin gallate (EGCG) is super-concentrated. Many supplements over-dose concentrated versions of EGCG. Recent studies suggest that the liver toxicity attributed to certain dietary supplements may have been a result of high EGCG concentrations6. However, the dosages found in green tea and other teas do not seem to be toxic, and may even be liver protective. This is probably just a case of too much of a good thing going bad. Use green tea extracts in moderation; if you have liver issues ask your hepatologist first.


Synephrine, often referred to as ‘bitter orange extract’, is a fat-burner with similar actions as ephedrine. It has had the dubious task of replacing ephedrine in dietary supplements. Unfortunately, synephrine isn’t quite as strong as ephedrine. Despite this inferiority complex, synephrine is beneficial as an ingredient in your fat burning supplement.

In a randomized double-blinded placebo controlled study, 50mg of synephrine produced a 65 Calorie increase in resting metabolic rate without any significant effects on heart rate or blood pressure7. In the same study, scientists also tried combining 2 other citrus bioflavonoids (hesperidin and naringin) with synephrine to observe any synergistic effects. The consumption of 600mg naringin with 50mg synephrine resulted in a 129 Calorie increase in metabolic rate. In the group receiving 100mg hesperidin with 50mg synephrine plus 600mg naringin, the metabolic rate increased by 183 Calories, an increase that was statistically significant with respect to the placebo control.

Pepper Extracts

Ever watch someone sweat while eating Three-Mile Island Hot Wings at Hooters? I have and the thermogenesis is unmistakable. Hot peppers make us sweat and sweat is fat crying right? Science supports the use of pepper extracts in our fat burning supplements.

In particular, capsaicin, the major pungent compound of red chili pepper, is a thermogenic ingredient which stimulates energy expenditure8. Capsaicin increased fat oxidation, limits appetite, and increases energy expenditure. Although some of these effects appear to be through SNS stimulation, again capsaicin has little effect on blood pressure. Interestingly, capsaicin supplementation appears to limit the decline in metabolism that occurs with calorie-restricted dieting8.

Beyond the well-studied effects above, capsaicin also appears to augment fat burning through other mechanisms. It is clear that capsaicin turns on metabolism through activation of brown fat9. More fascinating is that an animal model suggests that capsaicin may actually be able to turn on genes in white-storage-fat that cause it to convert to fat burning brown fat. It has also been suggested that capsaicin can alter the gut microbiota (much like pro-biotics) to help induce a fat burning animal. The power of probiotics as a fat burner will be a topic of future articles.

Black pepper isn’t quite as hot as chili peppers and isn’t even a true pepper (it’s a spice) but it too has valuable metabolic effects through its constituent, piperine. Piperine is a pungent component of black pepper much like capsinoids are with chili’s, albeit much lower on the Scoville scale. Piperine is thought to exert some of its beneficial effects via mechanisms similar to capsaicin. In mice fed a high fat and high sugar diet, investigators found diets with up to 0.05% piperine and 1% black pepper resulted in significantly less fat accumulation over 4 weeks10. In another study with rats fed a similar diet with piperine the treatment group experienced lower blood pressure, improved glucose levels, less oxidative stress, less inflammation, and improved liver function11. These findings suggest that piperine may be of value in burning fat while cutting or even prevent accumulating fat during bulk dieting. Human studies are needed!


Kaempferol is a small polyphenolic flavonoid found in broccoli, spinach, and berries. It appears to increase energy expenditure through thyroid hormone activation. It appears to do this through enhancing the conversion of less active T4 to the very active T3 molecule. This mechanism has been demonstrated in the laboratory through its actions on the enzyme deiodinase in human muscle cell cultures12. Furthermore, studies in cancer cells show that flavonoids like kaempferol and quercetin (quercetin being the strongest) are very strong inhibitors of fatty acid synthase13. Could this translate to your cruciferous veggies helping you burn fat? The fiber alone will help you absorb less fat, so eat your veggies!

Ursolic Acid

I previously wrote an article in MD about this compound and its fat burning, muscle increasing effects.   Ursolic acid appears to be an amazing compound in rodents in that increases muscle mass while keeping fat at bay. A recent study in humans supplemented 450mg of ursolic acid (from rosemary) in three divided doses of 150mg with meals over the course of 8 weeks, in weight trained subjects14. They found increased serum irisin (12%) and IGF-1 (22.8%) more than placebo, but no changes in body composition. They did find improvements in strength however. It would be interesting to see if this compound would help maintain muscle mass when dieting for a contest.

Fatty Acids

The effects of various fatty acids on your metabolism are astounding. Some fats are stored easier than others whereas other possess a thermic effect and burn efficiently. Fish oils, CLA, and MCT oils have all been shown to be effective mediators of fat storage and metabolsm1. The science is mixed, but healthy fats such as these may play an important role in your fat burning supplementation. A meta-analysis of the effects of CLA supplementation showed that 3.2 grams per day can produce modest fat loss15. It is important to note that when using fatty acids as part of your fat loss strategies that supplementing something like DHA won’t have any effect if you are eating 30g of saturated fat from beef every day. It would be like pissing in the ocean. You need to alter the ratios through supplementation AND food.

The Doctor OZ Failures

Dr. Oz has been taken to task by the U.S. Congress for his blatant use of inflammatory language to sell his miracle fat loss cures. Claims such as these are being taken very seriously by the FTC and they are taking action where the FDA has not. Dr. Oz has made many statements regarding Garcinia Cambogia, Raspberry ketones, and other compounds in recent years that made them fly off the shelves as fat burning supplements.

Garcinia Cambogia is a source of hydroxycitric acid (HCA). HCA inhibits an enzyme called citric acid lyase that is required for the synthesis of fat in your body. In rats, HCA appears to be able to limit the production of fat and reduce appetite. However, studies in humans show minimal effects and are quite variable in response. The studies that have shown a positive effect have been unimpressive16,17.

Raspberry Ketones are a flavoring agent used in processed foods found in red raspberries but often synthetically produced. They have a structure that is quite similar to synephrine, ephedrine, and capsaicin. In the lab, raspberry ketones show a strong effect on the metabolism of fat in cell cultures at very high concentrations19. Attaining such concentrations in humans seems quite unfeasible. In fact, there are no human studies that have examined the effects of this compound without combining it with others.