Yohimbine is the popularized name of a real tongue-twisting chemical known officially as 17 alpha-hydroxyyohimban-16 alpha-carboxylic acid methylester. Yet it has clinically verified aphrodisiac effects and is obtained from the bark of an African evergreen by the same name and growing in Cameroon, West Africa.
Yohimbe and yohimbine enjoy a considerable folkloric reputation as aphrodisiacs, that is, medications which stimulate sexual desire and performance. One recipe recommends boiling six to ten teaspoonfuls of inner bark shavings in a pint of water for a few minutes, straining, sweetening, and drinking the beverage. The alkaloidal salt yohimbine hydrochloride is usually administered in 5.4-mg doses. It is available as a prescription medication in a variety of combinations with other so-called sexual stimulants, including strychnine, thyroid, and methyltestosterone. Some authors recommend snuffing yohimbine to obtain both stimulant and mild hallucinogenic effects.
The medication dilates the blood vessels of the skin and mucous membranes but simultaneously increases blood pressure. Its alleged aphrodisiac effects are attributed not only to this enlargement of blood vessels in the sexual organs but to increased reflex excitability in the sacral (lower) region of the spinal cord. Early scientific studies of the aphrodisiac properties of yohimbine had produced unimpressive results. Then, in 1984, an investigation of the effect of relatively small doses in sexually active male rats concluded that the medication definitely increased sexual arousal in the treated animals. The investigators concluded that these results differed from those of earlier studies because the much larger doses of the medication previously employed produced other behavioral changes in the test animals. It is not yet possible to draw any firm conclusions regarding the aphrodisiac effects of yohimbe and yohimbine in human beings, but several studies give positive indications of their value.
Yohimbe is a weak monoamine oxidase inhibitor, but it also increases monoamine production, so its overall effect is that of a reasonably active MAO inhibitor. This means that tyramine-containing foods (liver, cheese, red wine, etc.) and nasal decongestants or certain diet aids containing phenylpropanolamine should be rigorously avoided if it is used. The medication also should not be taken by persons suffering from hypotension, diabetes, or from heart, liver, or kidney disease. Psychic reactions resembling anxiety have been shown to be produced by yohimbine. In the case of individuals suffering from schizophrenia, it may actually activate psychoses. These unpleasant and potentially hazardous reactions make it impossible to recommend the use of yohimbe for self-treatment. In any event, neither it nor yohimbine is now readily available over the counter in the United States, the latter having been declared both unsafe and ineffective by the FDA for over-the-counter sale.
German health authorities also do not recommend the therapeutic use of yohimbe for two reasons: insufficient proof of its effectiveness and a risk of serious side effects. Yohimbe products continue to be sold in the United States as dietary supplements, but they have been shown to be of extremely poor quality. Many were essentially devoid of yohimbine and lacked other alkaloids that would be expected to be present in authentic yohimbe bark. In both America and Britain, yohimbine tablets are often the subject of advertisements in reputable medical journals. It is unfortunate that an herbal product which has shown some promise of value in the treatment of psychogenic impotence and which is so readily available and apparently widely used, at least in Europe, should be so soundly condemned by health authorities, both here and abroad.
Since the new prescription medication Viagra has recently supplanted virtually all other treatments for impotence with success seldom seen before in any medication, either man-made or derived from nature, there is probably little hope for any new research on yohimbe. Still, it would be nice to know more about its safety and efficacy
Yohimbe is not used much in herbal medicine because of its potential toxicity. In western Africa, it is often employed as a stimulant and as a means to counter impotence.
HABITAT AND CULTIVATION Yohimbe is native to the forests of western Africa, especially Cameroon, Zaire, and Gabon. The bark is gathered at any time of year.
CONSTITUENTS Yohimbe contains about 6% indole alkaloids (including yohimbine), pigments, and tannins. The alkaloids have a cerebral stimulant action at moderate doses but are highly toxic in large doses. Yohimbine has been used in conventional medicine to treat impotence.
HOW MUCH YOHIMBE TO TAKE A tincture of the bark is often used in the amount of 5-10 drops three times per day. There are also standardized yohimbe products available for the treatment of impotence. A typical safe daily amount of yohimbine from any product is 15-30 mg. It is best to use yohimbine under the supervision of a nutritionally oriented doctor.
SIDE EFFECTS AND CAUTIONS Patients with kidney disease or peptic ulcer and pregnant or lactating women should not use yohimbe. Standard doses may sometimes cause dizziness, nausea, insomnia, or anxiety. Using more than 40 mg of yohimbine per day can cause dangerous side effects, including loss of muscle function, chills, and vertigo. Some people will also experience hallucinations when taking higher amounts of yohimbine. Foods with high amounts of tyramine (such as cheese, red wine, and liver) should not be eaten while a person is taking yohimbe, as it may cause severe hypertension and other problems. Similarly, yohimbe should only be combined with other antidepressant medications under the close supervision of a physician, although at least one study suggests it may benefit those who are not responding to serotonin reuptake inhibitors such as Prozac.
