What is Yohimbe?
Yohimbe is an evergreen tree that grows in western Africa in Nigeria, Cameroon, the Congo and Gabon. The bark of the tree contains the active compounds called alkaloids. The principal alkaloid is called yohimbine.
Yohimbine is a prescription drug in the United States for the treatment of erectile dysfunction. Its popularity has waned since the introduction of Viagra.
Yohimbe bark extracts are also sold in health food stores and online. In Germany, it is not approved for use. Yohimbe can cause a dangerous rise in blood pressure, as well as anxiety and other side effects.
The latin name for the herb yohimbe is Pausinystalia yohimbe.
Why Do People Use Yohimbe?
Traditionally, yohimbe was used in Africa for fever, coughs, leprosy, and as an aphrodisiac. Today, yohimbe is promoted for the following conditions:
1) Erectile Dysfunction
Yohimbe bark extracts are widely promoted online and in health food stores as a natural aphrodisiac to increase libido and treat erectile dysfunction. However, there is no evidence to show that the herbal supplements work. Most clinical studies have looked at the drug yohimbine and not the herbal extract yohimbe.
Yohimbine has been found to relax and dilate blood vessels in the penis, resulting in increased blood flow and erection. It may also stimulate areas in the brain involved in sexual desire.
Studies on the effectiveness of yohimbine have had conflicting findings. For organic erectile dysfunction (erectile dysfunction caused by a physical problem), one small uncontrolled study found that yohimbine was beneficial for men with organic erectile dysfunction. Another study found it was no more effective than a placebo.
Yohimbine appears to work better for erectile dysfunction not caused by a physical problem. A German study examined whether 30 mg/day of yohimbine for 4 weeks would help men with erectile dysfunction not due to a physical problem. Yohimbine was found to be more effective than placebo (71% vs 45%).
To date, there have been no studies comparing yohimbine to newer drugs such as Viagra.
2) Weight Loss
Yohimbine has been found to increase lipolysis by increasing the release of norepinephrine available to fat cells and blocking alpha-2 receptor activation. However, a controlled study found that 43 mg/day yohimbe had no effect on body weight, body mass index, body fat, fat distribution, and cholesterol levels.
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Yohimbe has been promoted as a herbal remedy for depression, because it blocks an enzyme called monoamine oxidase. However, this is only found in higher doses (over 50 mg/day), which is potentially unsafe.
In Germany, yohimbe is on the Commission E (the country's herbal regulatory agency). list of unapproved herbs because of concerns about the herb's safety and effectiveness. In the United States, the FDA has had a number of reports of seizures and kidney failure following the use of yohimbe.
Yohimbe is not recommended because it has a very narrow therapeutic index. There is a relatively small dosing range--below it, the herb doesn’t work and above it the herb is toxic.
Side effects of normal dosages may include dizziness, nausea, insomnia, anxiety, rapid heartbeat, and increased blood pressure.
As little as 40 mg a day can cause severe side effects, such as dangerous changes in blood pressure, hallucinations, paralysis. Overdose can be fatal.
Because yohimbe blocks the enzyme monoamine oxidase, people taking yohimbe must avoid all tyramine-containing foods (e.g., liver, cheeses, red wine) and over-the-counter products that contain the ingredient phenylpropanolamine, such as nasal decongestants.
People with kidney or liver disease, stomach ulcers, heart disease, high blood pressure, low blood pressure, post-traumatic stress disorder, and panic disorder should not take yohimbe.
Yohimbe should not be taken by pregnant or nursing women, children, or elderly people.
Yohimbe should not be combined with antidepressant drugs unless under the supervision of a physician.
Guay AT et al. "Yohimbine treatment of organic erectile dysfunction in a dose-escalation trial". International Journal of Impotence Research. 14.1 (2002):25-31.
Mann K et al. "Effects of yohimbine on sexual experiences and nocturnal penile tumescence and rigidity in erectile dysfunction". Archives of Sexual Behavior. 25.1 (1996):1-16.
Morales A et al. "Is yohimbine effective in the treatment of organic impotence? Results of a controlled trial". Journal of Urology. 137.6 (1987):1168-72.
Sax L. "Yohimbine does not affect fat distribution in men". International Journal of Obesity. 15.9 (1991):561-5.
Vogt HJ et al. "Double-blind, placebo-controlled safety and efficacy trial with yohimbine hydrochloride in the treatment of nonorganic erectile dysfunction". International Journal of Impotence Research. 9.3 (1997):155-61.