Yohimbine is an alkaloid found in the bark of a West African evergreen tree. Although historically regarded as an aphrodisiac, it was also popular with warriors who used it as a stimulant when preparing for battle. That's probably because it increases both heart rate and blood pressure, even at low doses. As to its sexual effects, yohimbine engorges blood vessels in the genitals of both men and women. It also raises blood levels of the neurotransmitter norepinephrine, which stimulates areas controlling sexual response in the brain.
Several studies confirm yohimbine s effectiveness.
For example, in the February 1998 issue of the Journal of Urology , researchers from the University of Exeter Medical School in England surveyed the available clinical trials and concluded that yohimbine should be considered as part of the first line of treatment for erectile dysfunction. The possible benefits, they found, outweigh the risks. But American Urological Association officials are not convinced. At the same time, concern about side effects is emerging. Published studies found few serious problems.