Yohimbe is the bark of the Pausinystalia yohimbe plant, an evergreen tree indigenous to western Africa. Yohimbe is sometimes used by athletes and weightlifters, who believe it can enhance performance, promote fat metabolism and help to build lean muscle mass. However, Blue Shield Complementary and Alternative Health notes that human clinical studies investigating yohimbe's effectiveness for weight loss and improved athletic performance are lacking. Yohimbe can be toxic if taken in excess. You should only use yohimbe under the supervision of a physician.
Yohimbe has been used in western Africa for a myriad of conditions, including cough, leprosy, angina and hypertension. It has also been employed as a local anesthetic and an aphrodisiac and employed ritually as a hallucinogen. Yohimbe, which increases blood flow, is often used to enhance male sexual function.
The main active constituent in yohimbe bark is an alkaloid called yohimbine. Drugs.com, which provides peer-reviewed medical information to consumers, credits yohimbine with vasodilatory effects, and says it increases production of norepinephrine and epinephrine, as well as raising blood pressure and accelerating heart rate. BSCAH concurs that yohimbe stimulates the nervous system, and says it also promotes the release of fat from cells and reduces appetite.
Gina Paulhus, a certified personal trainer in Newburyport, Mass., recommends yohimbe for promoting fat loss and reducing cellulite. Paulhus advises taking yohimbe orally or applying it as a topical cream 20 minutes before cardiovascular exercise, and says the herb should be taken on an empty stomach for best results. If you must eat after taking yohimbe, Paulhus advises eating lean protein over carbohydrates.
In a 2006 study published in "Research in Sports Medicine," researchers found that yohimbine significantly decreased body fat in elite athletes, but did not affect athletic performance either way. Other studies, however, have shown little effect on body fat. More study is needed on yohimbe's effect on body composition and athletic performance.
According to BSCAH, 15 to 30 mg of yohimbe is a safe daily amount, but you shouldn't take the herb if you have a kidney disorder, peptic ulcer, anxiety, panic disorder or high blood pressure. Yohimbe can cause nausea, dizziness and nervousness. Paulhus says a pre-workout dose of two 8-mg yohimbe capsules -- or a total of 16 mg -- is appropriate for a 160-lb. person. BSCAH warns against combining yohimbe with foods that contain high amounts of tyrosine -- such as cheese, red wine and liver -- and cautions that yohimbe can interact with antidepressants and other prescription drugs. Do not take yohimbe if you are pregnant or breast feeding.