Yohimbine provides a number of unique effects that enhance the fat loss during exercise, particularly in people that exercise regularly.
Derived from the bark of several trees, (most notably Pausinystalia yohimbe and Corynanthe yohimbe), Yohimbine seems to have almost a “drug-like” effect on fat metabolism.
Yohimbine is a highly unusual compound, firstly it’s a natural alpha-2 antagonist that promotes sympathetic activity by central as well as peripheral mechanisms to promote fat loss.
This unique ability to stimulate 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.
Exercise-induced lipolysis . . .
Another intriguing aspect of yohimbine is its effect on exercise-induced lipolysis. When taken before exercise, yohimbine is shown to boost the process of mobilizing fat from cells (lipolysis) and increase blood serum free fatty acid levels both during and after exercise – this may enable more fat to be burnt during and after exercise.
The extent of which exercise burns body fat is totally dependent upon the rate of lipolysis – that’s what makes yohimbine such a promising compound for fat loss.
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 suggests its the most potent lipolytic agent I’ve reviewed to date.
Yohimbine supplementation is shown to enhance exercise-induced FFA concentrations and norepinephrine release, both during and after exercise.[1,2] 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.[3] However, hold on to your recumbent bike, yohimbine’s unique benefits for fat metabolism, don’t stop there…
Beating the beta stimulators . . .
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.[4,5]
However, fat cells located around the hips and thighs characteristically contain very few beta receptors and respond poorly to catacholamine release. Fat cells located in this region contain a lot of alpha adrenoreceptors.[5] Releasing fat from alpha receptors is tricky. 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.[5] 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 must be read in your best “Soup Nazi” impersonation.)
If you’re a person that carries more fat on your hips and thighs, pre-exercise treatment with a supplement containing yohimbine may fix all that.
Yohimbine hit’s fat metabolism with a double-whammy – it’s a natural alpha-2 antagonist that promotes sympathetic activity (norepinephrine release) but also stimulates lipolysis via stimulation of the alpha-adrenoreceptors. Yohimbine administration increases lipolysis by antagonizing the anti-lipolytic activity of alpha-2 adrenoreceptors on fat cells.[4] This blockade of the alpha receptors by yohimbine results in increased fat mobilization from the stubborn cells and increases in blood FFA concentrations during and after exercise to promote better fat metabolism. Interestingly, the most positive effects are seen in females.[1,6]
Maximum effects with Methylxanthines . . .
Methylxanthines such as caffeine, green tea extracts and 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.[7]
While caffeine acts as an adenosine receptor antagonist, 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.[8] 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.
Research has shown that supplementation with yohimbine does not raise heart rate, increase blood pressure or induce any other undesired side effect that is characteristic of other stimulants. The addition of yohimbine to methylxanthines such as caffeine, theobromine and green tea extract makes a lot of sense. There is a strong mechanistic research-basis for more efficient fat metabolism during exercise. This is why the yohimbine is a key ingredient in the pre-workout powerhouse Dymetadrine Xtreme.
References:
1. Zahorska-Markiewicz B., Kucio C., Piskorska D. Adrenergic control of lipolysis and metabolic responses in obesity. Horm Metab Res 1986; 18: 693-697.
2. Lafontan M., Berlan M., Galitzky J., Montastruc J. L. Alpha-2 adrenoceptors in lipolysis: alpha 2 antagonists and lipid- mobilizing strategies. Am J Clin Nutr 1992; 55: 219S-227S.
3. Galitzky J., Taouis M., Berlan M., Riviere D., Garrigues M., Lafontan M. Alpha 2-antagonist compounds and lipid mobilization: evidence for a lipid mobilizing effect of oral yohimbine in healthy male volunteers. Eur J Clin Invest 1988;18: 587-594.
4. Lafontan M., Dang-Tran L., Berlan M. Alpha-adrenergic antilipolytic effect of adrenaline in human fat cells of the thigh: comparison with adrenaline responsiveness of different fat deposits. Eur J Clin Invest 1979; 9: 261-266.
5. Mauriege P., Galitzky J., Berlan M., Lafontan M. Heterogeneous distribution of beta and alpha-2 adrenoceptor binding sites in human fat cells from various fat deposits: functional consequences. Eur J Clin Invest 1987; 17: 156-165.
6. Kucio C., Jonderko K., Piskorska D. Does yohimbine act as a slimming drug? Isr J Med Sci 1991; 27: 550-556.
7. Vannucci S. J., Klim C. M., Martin L. F., LaNoue K. F. A1-adenosine receptor-mediated inhibition of adipocyte adenylate cyclase and lipolysis in Zucker rats. Am J Physiol 1989; 257: E871-E878.
8. Schlicker E., Gothert M. Interactions between the presynaptic alpha2-autoreceptor and presynaptic inhibitory heteroreceptors on noradrenergic neurones. Brain Res Bull 1998; 47: 129-132.
