Yohimbe is an herb derived from the inner bark of the yohimbe tree which grows wild throughout Africa. Long considered an a effective aphrodisiac, able to stimulate sexual desire and performance, yohimbe has been available by prescription as a pill. Recently yohimbe containing products have become popular as over the counter herbal preparations.
The active component of yohimbe bark is yohimbine, an alkaloid monoamine oxidase (MAO) inhibitor that blocks adrenergic receptors. This leads to an increase in dilation of blood vessels and a lowering of blood pressure. This enlargment of blood vessels, particularly in the sexual organs, is the generally accepted explanation of the physiological effects of the herb. Yohimbe also seems effective in elevating mood and reducing depression and anxiety, further contributing to its aphrodisiac activity.
Animal studies have shown that yohimbe does indeed increase sexual arousal and performance. Researchers conducting double-blind, placebo-controlled studies reported measurable improvements in sexual libedo and performance in men receiving the yohimbe versus those on placebo. Clearly in some cases yohimbe can improve sexual performance in those suffering from physiological and psychological impotence. Scientists have also recently found evidence that yohimbe may aid in weight loss by suppressing the body's ability to store fat.
Yohimbe is not without side-effects, which can include sweating, nausea and vomiting. Those taking MAO inhibitors such as tranquilizers, antidepressants or blood-pressure medications should not take yohimbe or any compounds containing yohimbine. Use of yohimbe is also contraindicated for pregnant women as well as persons with kidney disease, heart disease, liver disease, diabetes or ulcers. Persons with a history of psychoses should also avoid yohimbe as it has been known to trigger new episodes of psychic reaction.