Yohimbe

Botanical name: Pausinystalia yohimbe

Parts used and where grown

Yohimbe is a tall evergreen forest tree native to southwestern Nigeria, Cameroon, Gabon, and the Congo. The bark of this African tree is used medicinally. There are concerns, however, that the tree may be endangered due to over-harvesting for use as medicine.

Yohimbe has been used in connection with the following conditions (refer to the individual health concern for complete information):

Science Ratings	Health Concerns
	Erectile dysfunction
	Weight loss
	Depression
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Historical or traditional use (may or may not be supported by scientific studies)

Historically, yohimbe bark was used in western Africa for fevers, leprosy, and coughs.¹ It has also been used to dilate pupils, for heart disease, and as a local anaesthetic. It has a more recent history of use as an aphrodisiac and a hallucinogen.

Active constituents

The alkaloid known as yohimbine is the primary active constituent in yohimbe, although similar alkaloids may also play a role. Yohimbine blocks alpha-2 adrenergic receptors, part of the sympathetic nervous system.² It also dilates blood vessels. Yohimbine inhibits monoamine oxidase (MAO) and therefore may theoretically be of benefit in depressive disorders. However, it does not have the clinical research of other herbs used for depression, such as St. John’s wort.

Yohimbine has been shown in double-blind trials to help treat men with erectile dysfunction.³ ⁴ Although, negative studies have also been reported.⁵ ⁶

How much is usually taken?

Standardised yohimbe products are available. A safe daily amount of yohimbine from any product is 15–30 mg.⁷ Yohimbine should be used under the supervision of a physician. Traditionally, a tincture of the bark, 5–10 drops three times per day, has been used.

Are there any side effects or interactions?

Patients with kidney disease, peptic ulcer or pregnant or breast-feeding women should not use yohimbe.⁸ Standard amounts may occasionally cause dizziness, nausea, insomnia, anxiety, increased blood pressure, and rapid heart beat,⁹ though all of these are rare.¹⁰ 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.¹¹ Taking 200 mg yohimbine in one case led to only a brief episode of hypertension, palpitations, and anxiety.¹² People with post-traumatic stress disorder¹³ and panic disorder¹⁴ should avoid yohimbe as it may worsen their condition.

Foods with high amounts of tyramine (such as cheese, red wine, and liver) should not be eaten while a person is taking yohimbe, as they may theoretically cause severe high blood pressure and other problems. Similarly, yohimbe should only be combined with other antidepressant drugs under the supervision of a physician, though at least one study suggests it may benefit those who are not responding to serotonin reuptake inhibitors such as fluoxetine (Prozac®).¹⁵

Are there any drug interactions?
Certain medicines may interact with yohimbe. Refer to drug interactions for a list of those medicines.

Special United Kingdom considerations

Yohimbe may be prescribed by a doctor or dispensed under the supervision of a chemist.

References
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1. Duke J. CRC Handbook of Medicinal Herbs. Boca Raton, FL: CRC Press, 1985, 351.

2. Riley AJ. Yohimbine in the treatment of erectile disorder. Br J Clin Pract 1994;48:133–6.

3. Ernst E, Pittler MH. Yohimbine for erectile dysfunction: A systematic review and meta-analysis of randomized clinical trials. J Urol 1998;159:433–6.

4. Carey MP, Johnson BT. Effectiveness of yohimbine in the treatment of erectile disorder: Four meta-analytic integrations. Arch Sex Behav 1996;25:341.

5. Kunelius P, Häkkinen J, Lukkarinen O. Is high-dose yohimbine hydrochloride effective in the treatment of mixed-type impotence? A prospective, randomized, controlled double-blind crossover study. Urol 1997;49:441–4.

6. Mann K, Klingler T, Noe S, et al. Effect of yohimbine on sexual experiences and nocturnal tumescence and rigidity in erectile dysfunction. Arch Sex Behav 1996;25:1–16.

7. Goldberg KA. Yohimbine in the treatment of male erectile sexual dysfunction—a clinical review. Today’s Ther Trends J New Dev Clin Med 1996;14:25–33.

8. Drug Facts and Comparisons. St. Louis: Facts and Comparisons, 1998, 3659.

9. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 382–3.

10. Goldberg KA. Yohimbine in the treatment of male erectile sexual dysfunction—a clinical review. Today’s Ther Trends J New Dev Clin Med 1996;14:25–33.

11. Drug Facts and Comparisons. St. Louis: Facts and Comparisons, 1998, 3659.

12. Friesen K, Palatnick W, Tenenbein M. Benign course after massive ingestion of yohimbine. J Emerg Med 1993;11:287–8.

13. Bremner JD, Innis RB, Ng CK, et al. Positron emission tomography measurement of cerebral metabolic correlates of yohimbine administration in combat-related posttraumatic stress disorder. Arch Gen Psychiatry 1997;54:246–54.

14. Charney DS, Woods SW, Goodman WK, Heninger GR. Neurobiological mechanisms of panic anxiety: Biochemical and behavioral correlates of yohimbine-induced panic attacks. Am J Psychiatry 1987;144:1030–6.

15. Cappiello A, McDougle CJ, Maleson RT, et al. Yohimbine augmentation of fluvoxamine in refractory depression: A single-blind study. Biol Psychol 1995;38:765–7.

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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires March 2007.