The most positive effects of yohimbine on fat loss are seen in females.

Yohimbine and Fat Loss: "Yohimbine and Fat Loss: The Latest Research

by Paul Cribb, B.H.Sci HMS
AST Director of Research

Smart people should want to obtain the greatest possible fat-burning effect from their workouts. A review of the scientific literature on compounds that may enhance fat metabolism suggests that yohimbine is an overlooked supplement of great potential. Yohimbine provides a number of unique effects on the metabolism that may enhance the fat loss during exercise, particularly in people that exercise frequently.

Yohimbine: exactly what is it and what does it do?

Yohimbine is derived from the bark of several trees, most notably Pausinystalia yohimbe and Corynanthe yohimbe. Yohimbine is a naturally occurring compound that some researchers suggest has a “drug-like” effect on fat metabolism. Yohimbine is a highly unusual compound as it is a natural alpha-2 antagonist that promotes sympathetic activity by central as well as peripheral mechanisms to promote fat loss. (If you’re unsure what that means, I’ll clear that up shortly).

Additionally, research has shown that supplementation with yohimbine does not raise heart rate, increase blood pressure or induce undesired side effects. Best of all, when taken before exercise, yohimbine is shown to boost lipolysis (the process of mobilizing fat from cells) and increase blood serum free fatty acid levels both during and after exercise. These aspects make yohimbine a very exciting compound that may enable more fat to be utilized during and after exercise.

It's unique ability to stimulate fat cell alpha-2 adrenoreptors means that it provides an alternate biochemical pathway for fat metabolism compared to other traditional fat burning compounds such as caffeine. In fact, some research suggests that yohimbine may create a synergistic effect with the beta-receptor stimulants (such as caffeine and green tea extract) to accelerate fat loss during periods of intense training and calorie restriction.

Yohimbine boosts exercise induced lipolysis

The extent of which exercise burns body fat is totally dependent upon the rate of lipolysis. Lipolysis is the rate at which fat is mobilized from fat cells and enters the blood stream as free fatty acids (FFAs). Exercise triggers lipolysis, and highly trained individuals possess a greater lipolytic rate; an ability to “burn” more fat during exercise than untrained people. If you want the greatest possible fat-burning effect from exercise, then increasing your rate of lipolysis is the way to do it. The research on yohimbine supplementation suggests that this compound is the most effective lipolytic agent there is.

A high rate of lipolysis ensures greater fat metabolism by the liver and mitochondria in muscle cells during exercise. In turn, this process ensures that a greater concentration of body fat is burnt during exercise. When administered as a single oral dose, yohimbine is shown to elevate blood FFA concentrations. Additionally, yohimbine supplementation is shown to enhance exercise-induced FFA concentrations and norepinephrine release, both during and after exercise.[3,5] The impact of yohimbine on post-exercise fat metabolism is particularly evident 30-minutes after cardio exercise. One study showed that FFA levels in the blood doubled in those that took yohimbine prior to exercise compared to a placebo.[4]

Side effects

It is important to note that despite its ability to boost sympathetic tone and fat metabolism, yohimbine supplementation does not appear to influence cardiac function or blood pressure, even at high doses of 0.2 milligrams per kg of body weight.[6] Even when ingested in huge amounts, yohimbine is not toxic. Therefore yohimbine appears to be a safe nutritional supplement that most people can use to enhance fat loss.[7]

A highly unique fat burner

There are physiological differences in fat cells depending upon where they are located in the body. Fat cells located in the gut (visceral adipocytes) differ to fat cells located in the lower regions of the body (hips, thighs). Fat cells within the stomach contain a lot of beta-receptors. These cells respond and release fat when stimulated by the classic “beta-stimulating” compounds such as caffeine and ephedra. These compounds stimulate lipolysis specifically by increasing norepinephrine delivery to visceral fat cells and catecholamine secretion that activates the beta receptors and increases cAMP within cells.[11,12]

However, fat cells located around the hips and thighs characteristically contain very few beta receptors and respond poorly to catacholamine release that is induced by exercise and beta-stimulants. However, these lower body fat cells contain a lot of alpha adrenoreceptors.[12] Alpha receptors are tricky little bastards if you want them to release their fat stores. When stimulated, these receptors activate other proteins that inhibit adenyl-cyclase, thus antagonizing the ability of beta-adrenoreceptors to boost cAMP generation and therefore, shut down the usual fat mobilization process.[12] Essentially, when you take caffeine and ephedrine supplements in an effort to stimulate fat loss, the alpha receptors on lower-body fat cells say “No! No fat mobilization for you!” (If you’re a Seinfeld fan, the last sentence should be read in your best “Soup Nazi” impersonation.)

Fat cells within the lower half of the body contain a higher concentration of alpha receptors and low concentration of beta receptors and therefore, are much more resistant to lipolysis.[13] Women characteristically carry more fat on their hips and thighs than men, and this difference in fat cell structure is one reason why most women have a tougher battle with fat loss. However, pre-exercise treatment with yohimbine may fix all that.

Yohimbine is a natural alpha-2 antagonist that promotes sympathetic activity (norepinephrine release) but also stimulates lipolysis via stimulation of the alpha-adrenoreceptors. Research has shown that yohimbine administration increases lipolysis by antagonizing the anti-lipolytic activity of alpha-2 adrenoreceptors on fat cells.[11] This blockade of the alpha receptors by yohimbine results in increased fat mobilization from these stubborn cells and increases in blood FFA concentrations during and after exercise to ensure a high rate of fat metabolism. Interestingly, the most positive effects of yohimbine on fat loss are seen in females.[3,8]

The prolipolytic activity of yohimbine is only significant for about an hour, but that’s all you need to enhance the fat mobilizing effect of aerobic exercise. But don’t worry, yohimbine’s effect on sympathetic activity lasts for 4 hours or more. Therefore, the fat loss benefits are long lasting, particularly if it is taken in combination with methylxanthines such as caffeine.

Synergistic effect with caffeine

Increased lipolysis and fat utilization is a hall mark of caffeine supplementation.[1,2] Pre-exercise supplementation with caffeine (5milligrams per kilograms of body weight) has been shown to boost lipolysis while lowering the respiratory quotient (a signal of fat utilization) during and following aerobic exercise.[6] Methylxanthines such as caffeine (and possibly theobromine) seem to be the central component to enhancing fat metabolism during exercise as they act as adenosine receptor antagonists in nerve cell junctions to prolong or enhance sympathetic (neural) activity.[10]

In a previous article on green tea extract, I explained how this compound enhances the fat burning effects of caffeine. However, it also appears likely that caffeine and green tea extract would enhance/prolong the metabolic activity seen with yohimbine supplementation.

While caffeine acts as adenosine receptor antagonists, yohimbine exerts a synergistic effect by blocking alpha-2 adrenoreceptor activation. Intriguingly, alpha-2 adrenoreceptor blocking appears to up-regulate expression of pre-synaptic adenosine receptors.[9] In other words, chronic inhibition of one type of feedback receptor will be compensated by increased function of the other type. Thus, the combination of yohimbine with caffeine and green tea extract should create a synergistic effect on central sympathetic activation that enables these supplements to exert their full force on lipolysis and fat metabolism. Most importantly, these benefits seem to be achieved without any undesired side effects.

SummaryDytemtadrine Xtreme


Regarding effective dosages for yohimbine, some research has shown positive effects using a daily dose of 12-16 milligrams a day.[3,8,14] However, this was yohimbine taken on its own, this research did not take into account the synergistic effect of combining caffeine with yohimbine on fat metabolism. If combined with caffeine and other fat loss compounds such as green tea extract, a smaller dose should provide a rather potent effect on lipolysis and fat metabolism.

Research that has examined the biochemical pathways that trigger increased fat metabolism have revealed that combining yohimbine with other fat loss compounds such as caffeine provide a true synergistic effect on fat metabolism. This effect is yet to be demonstrated by other supplements. Of all the fat loss compounds on the market, the addition of yohimbine to methylxanthines such as caffeine, theobromine and green tea extract makes a lot of sense. This combination has a strong mechanistic research-basis that suggests it provides active people with very effective method to shed more fat during exercise."