Yohimbe bark extract (Pausinystalia yohimbe Pierre ex Beille Rubiaceae)
Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
Aphrodien, Corynanthe johimbi, Corynanthe yohimbi, corynine, iohimbina (Brazilian Portuguese), johimbe (Danish, Dutch, English, Hungarian), johimbi, kiima-johimbepuu (Estonian), P. yohimbe (CCD-X), Pausinystalia johimbe, Pausinystalia yohimbe, quebrachine, Rubiaceae (family), yohimbehe, yohimbehe cortex, yohimbeherinde, yohimbene, yohimbime, yohimbine, P.johimbe (Schumann) Beille.
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. In general, there is a lack of clinical research on yohimbe bark extract, which generally contains low concentrations of yohimbine (6% indole alkaloids, of which only 10-15% is yohimbine), and commercial preparations may or may not share the pharmacological and clinical effects of yohimbine hydrochloride
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Athletic performance (body/muscle mass)
Historically, yohimbe has been used for body building and enhancing athletic performance. Due to stimulatory effects on the sympathetic nervous system, it has been postulated that yohimbe may enhance exercise performance, increase fat loss and increase muscle mass. A single small study found no effect on total body mass or body muscle mass, but a decrease in fat mass among athletes. Further study is needed before a conclusion can be made.
Preliminary clinical study suggests that yohimbine hydrochloride may improve symptoms of depression. However, yohimbe bark extract may not contain significant amounts of yohimbine and therefore may not have antidepressant effects. More research is needed before a firm conclusion can be made.
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.
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.
Orgasm improvement (men)
Yohimbine hydrochloride has been suggested as a potential agent to improve orgasmic dysfunction. However, studies in humans in this area are limited. More well designed studies are needed before a conclusion 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.
*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.
Alzheimer's disease, anesthetic, aphrodisiac, atherosclerosis, chest pain, cognition, coronary artery disease, cough, diabetic complications, exhaustion, feebleness, fevers, hallucinogenic, high cholesterol (hyperlipidemia), insomnia, leprosy, low blood pressure (hypotension), narcolepsy, obesity, panic disorder, Parkinson's disease, poisoning (clonidine overdose), pupil dilator, schizophrenia (decreasing auditory evoked response/sensory gating), stimulant, syncope (neurally-mediated).
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (over 18 years old)
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 athletic performance, 20 milligrams of yohimbine (twice daily for 21 days) has been taken with no evidence of benefit; For erectile dysfunction (male impotence), 5 to 50 milligrams of yohimbine hydrochloride daily in three divided doses (for example, 5.4 to 10 milligrams three times daily for 2-8 weeks) has been studied. For libido in women, 5.4 milligrams three times daily for three months of yohimbine hydrochloride has been studied. For sexual side effects caused by antidepressant drugs, 2.7 to 16.2 milligrams of yohimbine hydrochloride prior to sexual intercourse or daily doses of 15-18mg have 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.
Children (under 18 years old)
Yohimbe and yohimbine hydrochloride are not recommended for use in children.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
In theory, allergy/hypersensitivity to yohimbe, any of its constituents, or yohimbine-containing products may occur.
Side Effects and Warnings
Yohimbine is generally well tolerated in recommended doses. However, many side effects have been reported with yohimbine hydrochloride and may apply to yohimbe bark. Yohimbe bark extract is traditionally said to cause occasional skin flushing, piloerection (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.
Use cautiously in patients with blood disorders or who use blood thinners; in those with cardiovascular disease; in those with diabetes or who use agents that lower blood sugar or insulin; in those with seizure disorder; in those that use selective serotonin reuptake inhibitors (SSRIs) or tricyclic (TCA) antidepressants; in patients with asthma or other respiratory disease; in those with insomnia; in those using central nervous system (CNS) depressants, alpha blockers, ACE inhibitors, angiotensin II receptor antagonists, beta blockers, calcium channel blockers, diuretics, guanabenz, or guanethidine; in individuals with systemic lupus erythematosus, liver or kidney disease, or a history of kidney failure.
Avoid in patients taking monoamine oxidanse inhibitors (MAOIs) or mood stabilizers and in pregnant and lactating women, Yohimbine should be avoided in children.
Pregnancy & Breastfeeding
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.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Multiple drug interactions may occur with the use of yohimbine hydrochloride. In theory, these effects may also apply to yohimbe bark extract, which contains variable (usually low) amounts of yohimbine.
Based on human study, yohimbine has been reported to block the effects of alpha-adrenergic drugs. Yohimbine may increase the effects of drugs that are anti-adrenergic, such as clonidine or guanabenz. Use of yohimbine with central nervous system stimulants may have additive effects. In theory, due to inhibition of monoamine oxidase (MAOI activity), use of yohimbine with drugs like isocarboxazid (Marplan®), phenelzine (Nardil®), tranylcypromine (Parnate®), or linezolid (Zyvox®) may produce additive side effects, such as an increased risk of extremely high blood pressure. High blood pressure has also been reported when yohimbine is taken with tricyclic antidepressants.
Based on human study, use of ethanol (alcohol) with yohimbine may produce an additive effect of increasing intoxication. Based on human study, yohimbine may increase pain relief from morphine and may increase or decrease withdrawal symptoms caused by the medication naloxone. According to historical use and animal study, yohimbine may increase the effects of diabetic medications, including insulin, although there is no reliable scientific evidence in this area. Caution is advised when using medications that may lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.
Based on human study, use of yohimbine with physostigmine in patients with Alzheimer's disease may be associated with anxiety, agitation, restlessness, and chest pain. Use of yohimbine with antihistamines is cautioned, although there is no reliable scientific evidence in this area. The combination of yohimbine with anti-muscarinic agents may result in increased risk of toxicity. In theory, yohimbine may add to the effects of drugs that lower blood pressure.
In theory, yohimbine may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs (and yohimbine) in the blood may be altered and may cause increased or decreased effects or potentially serious adverse reactions. Patients using any medications should check the package insert and speak with a qualified healthcare professional or pharmacist about possible interactions.
Yohimbine may also interact with benzodiazepines (tranquilizers), antibiotics such as linezolid, phenothiazines, and tricyclic antidepressants (TCAs). Patients using any medications should check the package insert and speak with a qualified healthcare professional or pharmacist about possible interactions.
Based on evidence in clinical study of antiplatelet activity, yohimbine hydrochloride may increase the risk of bleeding with taken with blood thinning drugs.
Laboratory study has demonstrated antiandrogenic properties of yohimbine hydrochloride. Theoretically, yohimbine may inhibit the effect of androgens, such as testosterone, and may increase the effects of antiandrogen agents, such as leuprolide and spironolactone. Yohimbine has also been reported to interact with other hormonal agents.
Yohimbine hydrochloride has been reported to have serotonin reuptake inhibitor effects, and theoretically may increase the efficacy of similar drugs, such as fluoxetine (Prozac(R)). However, there is insufficient clinical evidence of this effect.
Yohimbine hydrochloride has been reported to lower to seizure threshold. Theoretically, it may increase the risk of seizure when taken with other medications that lower the seizure threshold. It may also reduce the effectiveness of antiseizure medications. Yohimbine has also been shown to have effects on the central nervous system, such as increasing anxiety and restlessness. Theoretically, it may interact with medications used to treat neurological conditions.
Yohimbine may block the effects of medications that lower blood pressure.
Over-the-counter (OTC) products containing stimulants, including caffeine, phenylephrine, phenylpropanolamine (removed from the US market), may lead to additive effects when used in combination with yohimbe bark extract.
Yohimbine may increase or decrease the effects of drugs used to treat opioid overdose (naloxone/naltrexone).
Interactions with Herbs and Dietary Supplements
Multiple interactions may occur between the drug yohimbine hydrochloride and herbs/supplements. In theory, these effects may also apply to yohimbe bark extract, which contains variable (usually low) amounts of yohimbine.
In theory, other over-the-counter products containing stimulants, including caffeine, phenylephrine, and phenylpropanolamine (removed from the U.S. market), may lead to additive effects when used in combination with yohimbine. Yohimbine theoretically may interfere with blood pressure control and should be used cautiously with other herbs or supplements that affect blood pressure.
Due to inhibition of monoamine oxidase, use of yohimbine with herbs/supplements with possible similar properties may produce additive effects, such as an increased risk of dangerously high blood pressure (hypertensive crisis). In theory, caffeine-containing agents such as coffee, tea, cola, guarana, and mate may also increase the risk of hypertensive crisis when taken with yohimbine.
Yohimbine theoretically may add to the effects of herbs or supplements that may lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
In theory, yohimbine may interfere with the way the body processes herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of herbs or supplements (and yohimbine) in the blood may be altered, and may cause increased or decreased effects or potentially serious adverse reactions. It may also alter the effects that other herbs or supplements possibly have on the P450 system.
Other possible interactions with yohimbine include herbs and supplements used for Alzheimer's disease, bacterial infections, or depression. In theory, yohimbine may interact with goldenseal or berberine-containing herbs.
Based on evidence in clinical study of antiplatelet activity, yohimbine hydrochloride may increase the risk of bleeding with taken with blood thinning supplements.
Laboratory study has demonstrated antiandrogenic properties of yohimbine hydrochloride. Theoretically, yohimbine may inhibit the effect of androgens, and may increase the effects of antiandrogen agents. Yohimbine has also been reported to interact with other hormonal agents.
Yohimbine hydrochloride has been reported to have serotonin reuptake inhibitor effects, and theoretically may increase the efficacy of supplements that affect the serotonin pathway.
Yohimbine hydrochloride has been reported to lower to seizure threshold. Theoretically. it may increase the risk of seizure when taken with other supplements that lower the seizure threshold. It may also reduce the effectiveness of antiseizure supplements. Yohimbine has also been shown to have effects on the central nervous system, such as increasing anxiety and restlessness. Theoretically, it may interact with agents used to treat neurological conditions.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
Adeniyi AA, Brindley GS, Pryor JP, et al. Yohimbine in the treatment of orgasmic dysfunction. Asian J Androl 2007 May;9(3):403-7. View Abstract
Bagheri H, Schmitt L, Berlan M, et al. A comparative study of the effects of yohimbine and anetholtrithione on salivary secretion in depressed patients treated with psychotropic drugs. Eur J Clin Pharmacol 1997;52(5):339-342. View Abstract
Balon R. Fluoxetine-induced sexual dysfunction and yohimbine. J Clin Psychiatry 1993;54(4):161-162. View Abstract
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Carey MP, Johnson BT. Effectiveness of yohimbine in the treatment of erectile disorder: four meta-analytic integrations. Arch Sex Behav 1996;25(4):341-360. View Abstract
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Knoll LD, Benson RC Jr, Bilhartz DL, et al. A randomized crossover study using yohimbine and isoxsuprine versus pentoxifylline in the management of vasculogenic impotence. J Urol. 1996;155(1):144-146. View Abstract
Kunelius P, Hakkinen J, Lukkarinen O. Is high-dose yohimbine hydrochloride effective in the treatment of mixed-type impotence? A prospective, randomized, controlled double-blind crossover study. Urology 1997;49(3):441-444.
Landis E, Shore E. Yohimbine-induced bronchospasm. Chest 1989;96(6):1424. View Abstract
Montague DK, Barada JH, Belker AM, et al. Clinical guidelines panel on erectile dysfunction: summary report on the treatment of organic erectile dysfunction. The American Urological Association. J Urol 1996;156(6):2007-2011. View Abstract
Ostojic SM. Yohimbine: the effects on body composition and exercise performance in soccer players. Res Sports Med 2006 Oct-Dec;14(4):289-99. View Abstract
Vogt HJ, Brandl P, Kockott G, et al. Double-blind, placebo-controlled safety and efficacy trial with yohimbine hydrochloride in the treatment of nonorganic erectile dysfunction. Int J Impot Res 1997;9(3):155-161. View Abstract
Copyright © 2013 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
March 22, 2017