Aphrodien, Corynanthe johimbi, Corynanthe yohimbi, corynine, johimbi, Pausinystalia johimbe, Pausinystalia yohimbe, quebrachine, Rubiaceae (family), yohimbehe, yohimbehe cortex, yohimbeherinde, yohimbene, yohimbime, yohimbine.
The terms yohimbine, yohimbine hydrochloride, and yohimbe bark extract are related but not interchangeable. Yohimbine is an active chemical (indole alkaloid) found in the bark of the Pausinystalia yohimbe tree. Yohimbine hydrochloride is a standardized form of yohimbine that is available as a prescription drug in the United States and has been shown in human studies to be effective in the treatment of male impotence. Yohimbine hydrochloride has also been used for the treatment of sexual side effects caused by some antidepressants (SSRIs), female hyposexual disorder, as a blood pressure boosting agent in autonomic failure, xerostomia, and as a probe for noradrenergic activity.
Dry mouth (xerostomia):
Studies report that yohimbine is able to increase saliva in animals and in humans. Based on these few studies, yohimbine has been used for the treatment of dry mouth caused by medications, such as antidepressants. However, yohimbe bark extract may not contain significant amounts of yohimbine and therefore may not have these effects. More research is needed before a strong recommendation can be made.
Erectile dysfunction (male impotence):
Yohimbine hydrochloride is a prescription drug that has been shown in multiple human trials to effectively treat male impotence. Yohimbine may also be a useful treatment option in orgasmic dysfunction. Although yohimbine is present in yohimbe bark extract, levels are variable and often very low. Therefore, although yohimbe bark has been used traditionally to reduce male erectile dysfunction, there is not enough scientific evidence to form a firm conclusion in this area.
Inhibition of platelet aggregation:
Pre-clinical studies report that yohimbine alkaloid, isolated from yohimbe bark, may inhibit platelet aggregation. Research in humans is limited, and more research is necessary in this area.
Libido (women) :
Yohimbine has been proposed to increase female libido (sexual interest). There is only limited poor-quality research in this area, and more study is needed before a strong recommendation can be made.
Nervous system dysfunction (autonomic failure):
It is theorized that yohimbine may improve orthostatic hypotension (lowering of blood pressure with standing) or other symptoms of autonomic nervous system dysfunction. However, yohimbe bark extract may not contain significant amounts of yohimbine, and therefore may not have these proposed effects. More research is needed before a strong recommendation can be made.
Sexual side effects of selective serotonin reuptake inhibitor (SSRI) antidepressants:
Yohimbine hydrochloride, a standardized form of yohimbine that is available as a prescription drug in the United States, has been suggested to treat sexual dysfunction due to SSRI antidepressants. However, research in this area is limited, and more study is needed before a recommendation can be made. In addition, yohimbe bark extract may not contain significant amounts of yohimbine and therefore may not have these proposed effects.
Muscle mass / body mass:
Yohimbine combined with resistance training does not appear to alter body mass, muscle mass, or exercise performance.
The following doses are based on human trials of pharmaceutical standardized yohimbine hydrochloride (available by prescription in the United States). No reliable clinical studies are available for administration of yohimbe bark extract. For erectile dysfunction (male impotence), 15 to 42 milligrams of yohimbine hydrochloride daily in three divided doses (for example, 5.4 to 10 milligrams three times daily) has been studied. For libido in women, 5.4 milligrams three times daily of yohimbine hydrochloride has been studied. For sexual side effects caused by antidepressant drugs, 2.7 to 16.2 milligrams of yohimbine hydrochloride has been studied. For autonomic dysfunction/orthostatic hypotension, 5.4 to 12 milligrams of daily yohimbine has been studied. For dry mouth (xerostomia), 6 milligrams three times daily of yohimbine hydrochloride has been studied.
Yohimbe and yohimbine hydrochloride are not recommended for use in children.
In theory, allergy/hypersensitivity to yohimbe, any of its constituents, or yohimbine-containing products may occur.
Yohimbe bark extract is traditionally said to cause occasional skin flushing, piloeretion (body hair standing up), painful urination, genital pain, reduced appetite, agitation, dizziness, headache, irritability, nervousness, tremors, or insomnia.
Multiple adverse effects have been associated with the use of the drug yohimbine hydrochloride, although in recommended doses, it is usually tolerated. If adverse effects occur, discontinuing the drug will likely stop the effects. In theory, these same side effects may also occur with the use of yohimbe bark extract, which contains variable (usually low) amounts of yohimbine.
There are reports of rash, flushing, breathing difficulty, cough, runny nose, nausea, vomiting, increased salivation, diarrhea, increased frequency of urination, kidney failure, muscle aches, and a lupus-like syndrome with the use of yohimbine hydrochloride. Yohimbine has also been associated with tremulousness, insomnia, anxiety, irritability, and excitability. Yohimbine may precipitate panic attacks, anxiety, manic episodes, or psychosis in patients with a history of mental illness.
In animal research, yohimbine has been associated with increased motor activity and seizures at higher doses. In humans, yohimbine may change the seizure threshold (the likelihood that a seizure will happen in some people) and may cause blood pressure/heart rate increases, fluid retention, chest discomfort, and heart rhythm abnormalities. Higher doses may lower blood pressure. Yohimbine can enter the brain through the bloodstream. Yohimbine may increase the risk of bleeding by altering platelet function and may dangerously reduce the number of white blood cells (agranulocytosis).
Symptoms of toxicity from yohimbine can include paralysis, dangerously low blood pressure, heart rhythm abnormalities, heart failure, and death. These same risks theoretically may also exist with yohimbe bark extract, depending on the concentration of yohimbine present and the amount ingested. Beta-blocker drugs such as metoprolol (Lopressor®, Toprol®) may be protective against yohimbine toxicity.
Yohimbe should be avoided during pregnancy because it may relax the uterus and may be toxic to the fetus. Yohimbe should be avoided during breastfeeding, due to reports of deaths in children.