Yohimbe is derived from the bark of a west African evergreen tree. Yohimbine is an active chemical (an alkaloid) found in said bark and is cultivated into supplement form. Yohimbine hydrochloride is a standardized form of yohimbine that is available as a prescription drug in the United States. Yohimbe dilates the blood vessels and can lower blood pressure. “So experts figured, if it can do that, it must give you an erection and treat erectile dysfunction.” Some proponents say that yohimbe extracts are powerful antioxidants that can prevent heart attacks, act as a stimulant and an anti-depressant.