Yohimbe

The bark of the West African yohimbe tree is a traditional aphrodisiac and the source of yohimbine, a prescription drug for impotence. Yohimbine (the drug) is only modestly effective at best, better than placebo but only successful in about 30 to 45% of the men who use it. However, it seems to work even in men whose impotence is caused by a serious illness such as diabetes. One small double-blind study on women found yohimbine combined with arginine to be somewhat effective for treating women with sexual dysfunction. An open trial of yohimbine alone to treat sexual dysfunction induced by the antidepressant fluoxetine (Prozac) found improvement in eight out of nine people, two of whom were women. However, in the absence of a placebo group, these results cant be taken as reliable; in addition, there are concerns about the safety of combining yohimbe with antidepressants. We dont really know how yohimbine works, but recent thinking suggests that it operates by suppressing parts of the brain that keep sexual arousal under control. In other words, it takes the brake off, which can be useful when the engine has lost some of its power.

Like the drug yohimbine, the bark of the yohimbe tree is widely used to treat impotence. Many herbalists report that the herb is more effective than the purified drug, perhaps due to the presence of other unidentified active ingredients. However, there have been no good studies to prove this. Yohimbe is also sometimes recommended as an antidepressant. However, its effectiveness is unknown and there are much safer herbs for this purpose, such as St. Johns wort.

Yohimbe bark is best taken in a form standardized to yohimbine content. Most people take a dose that supplies 15 to 30 mg of yohimbine daily. However, higher doses are not necessarily better, and some people respond optimally to 10 or even 5 mg daily. Furthermore, while some people appear to respond immediately to a single dose, for others it takes 2 to 3 weeks of treatment to provide significant benefits. Because yohimbine is a somewhat dangerous substance (see Safety Issues), we recommend a physicians supervision when taking it.

Yohimbe should not be used by pregnant or nursing women, or those with kidney, liver, or ulcer disease or high blood pressure. Dosages that provide more than 40 mg a day of yohimbine can cause a severe drop in blood pressure, abdominal pain, fatigue, hallucinations, and paralysis. (Interestingly, lower dosages can cause an increase in blood pressure.) Since 40 mg is not very far above the typical recommended dose, yohimbe has what is known as a narrow therapeutic index. This means that there is a relatively small dosing range, below which the herb doesn't work and above which it is toxic. Even when taken in normal dosages, side effects of dizziness, anxiety, hyperstimulation, and nausea are not uncommon. Yohimbe is not recommended for young children, pregnant or nursing women, or those with severe liver or kidney disease.

If you are taking tricyclic antidepressants, phenothiazines, clonidine, other drugs for lowering blood pressure, central nervous system stimulants: don't use yohimbine.