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Other common
name(s): yohimbe, yohimbe bark, yohimbine hydrochloride,
johimbe, Actibine, Aphrodyne, Dayto Himbin, Yocon, Yohimex, Yomax
Scientific/medical
name(s): Pausinystalia
yohimbe, (Corynanthe
yohimbe)
Description
Yohimbe is an evergreen tree native to western Africa,
specifically the countries of Nigeria, Cameroon, Gabon, and the Congo.
It can reach a height of 90 feet. The dried bark is used in folk and
herbal remedies.
The drug yohimbine hydrochloride (called yohimbine), is
derived from yohimbe bark, and has been approved by the U.S. Food and
Drug Administration (FDA) for prescription use only.
Overview
Yohimbe bark has been used as an aphrodisiac for many years.
It has been declared an unsafe herb in Germany because of such
complications as increased heart rate and blood pressure and even
kidney failure. In the United States, supplements that are labeled as
containing yohimbe bark often contain very little of it.
On the other hand, yohimbine hydrochloride, the substance in
yohimbe bark thought to help with erections, is regulated as a
prescription drug and is standardized to contain a precise amount of
the labeled ingredient. It is mainly used as a treatment for erectile
dysfunction (impotence), although there are concerns about its side
effects and interactions with other medicines, alcohol, and even some
foods. Yohimbine hydrochloride is often called simply yohimbine,
although it is made under several brand names.
How is it promoted for use?
Yohimbe bark extract is promoted as an aphrodisiac and sexual
enhancer for men and women. Proponents say that yohimbe extracts are
powerful antioxidants that can prevent heart attacks. Some also tout it
is as a stimulant, antidepressant, and aid to weight loss.
Yohimbine hydrochloride, often simply called yohimbine, is
thought to be the most vital active ingredient of yohimbe bark. The
drug yohimbine is available by prescription for the treatment of
erectile dysfunction and is supposed to improve blood flow to the
penis. It has also been promoted to treat exhaustion, drug overdose
(from clonidine), and a form of low blood pressure that occurs when
standing, called postural hypotension. Yohimbine can also be used to
enlarge the pupil of the eye to help doctors examine the inside of the
eyes.
What does it involve?
Yohimbe bark and bark extracts are sold as capsules, tablets,
liquids, and powders. Some people make the bark into a tea, while
others place the powdered bark under the tongue or sniff it.
Extracts and supplements labeled as yohimbine that are sold in
health food stores and over the Internet contain varying amounts of
yohimbe and other ingredients. FDA researchers analyzed a number of
commercial yohimbe bark products available over the counter. They found
that the supplements contained less of the amount of yohimbine that
would be found in actual yohimbe bark and also contained substances
that do not occur in yohimbe bark.
The prescription form of yohimbine is strictly regulated by
the FDA. It is approved only for the treatment of impotence and is
available in tablets and capsules. The standard dosage is 5.4
milligrams taken 3 times a day for no longer than 10 weeks.
What is the history behind it?
In Africa, yohimbe has been used for generations as an
aphrodisiac and a treatment for erectile dysfunction. It was also used
to treat fevers, leprosy, high blood pressure, and heart problems. In
addition, it was used by warriors as a stimulant before battle. The
powder was sometimes smoked to induce hallucinations, and yohimbe
poultices were placed on the skin as an antiseptic and treatment for
pain. In the 1890s, yohimbe began to be used medicinally in Europe.
Yohimbe has been used to treat erectile dysfunction for more than 100
years.
After manufacturers purified the substance called yohimbine
hydrochloride from the tree's bark, it has been sold by prescription
only in the United States. Yohimbe was in use by 1938, before new drugs
were required to be reviewed and approved by the FDA. When stricter
regulatory practices were introduced, sales of existing drugs were
allowed to continue. Its popularity has decreased as sildenafil
(Viagra) and similar drugs were approved starting in the late 1990s.
Even with this decline in popularity, there is concern that the yohimbe
trees of Africa are being killed by over-harvesting because of
yohimbe's popularity as a drug and dietary supplement.
What is the evidence?
Most clinical trials have looked at yohimbine, rather than at
yohimbe bark. Clinical trials have found contradictions regarding the
effectiveness of yohimbine for treating erectile dysfunction. The
American Urological Association guidelines on treatment of erectile
dysfunction state that it could not draw conclusions about yohimbine's
effectiveness and safety and that larger studies are needed to evaluate
it.
A randomized clinical trial found that yohimbine may be a
useful treatment for erectile dysfunction caused by psychological
problems. Another randomized clinical study found that yohimbine was no
better than a placebo as a first treatment for erectile dysfunction
that had some physical basis. Other studies with yohimbine have shown
it helps some with mild erectile problems, even those that have a
physical basis. A review study concluded that yohimbine has a modest
effect on erectile dysfunction caused by psychological factors, but not
on erectile dysfunction due to physical causes. It appears that more
research needs to be done to clarify the role of yohimbine in the
treatment of erectile dysfunction. No studies to date have compared
yohimbine to newer treatments for this problem.
It is important to note that these studies were done using the
drug yohimbine. Extracted chemicals are not the same as yohimbe bark.
Studies of yohimbine would be expected to produce different results
from studies using the raw plant. The unpurified plant extract would
have different amounts of active compounds, more compounds that may
cause unexpected effects, and many other differences.
Yohimbine is now being used with other substances for the
treatment of erectile dysfunction and may be helpful for men who cannot
take the newer drugs for impotence. A 2002 study looked at yohimbine
combined with L-arginine glutamate (a substance thought to affect
erections), given to 45 men as a one-time dose 1 to 2 hours before
intended sexual intercourse. Results showed that it worked better than
placebo, although men with mild to moderate erectile dysfunction had
more improvement than those with more severe problems.
Yohimbine has also been tested in small studies with people
who have low blood pressure and in those who faint after standing up.
It appeared to be somewhat helpful, but more studies need to be done
before it can be recommended for this use. Early studies have also
suggested that it can dilate the pupil of the eye to help doctors
examine the inside of the eye, but more information is needed. Several
other drugs are available and widely used for that purpose by eye
specialists.
Are there any possible problems or
complications?
This product is sold as a
dietary supplement in the United States. Unlike companies that produce
drugs (which must provide the FDA with results of detailed testing
showing their product is safe and effective before the drug is approved
for sale), the companies that make supplements do not have to show
evidence of safety or health benefits to the FDA before selling their
products. Supplement products without any reliable scientific evidence
of health benefits may still be sold as long as the companies selling
them do not claim the supplements can prevent, treat, or cure any
specific disease. Some such products may not contain the amount of the
herb or substance that is written on the label, and some may include
other substances (contaminants). Though the FDA has written new rules
to improve the quality of manufacturing processes for dietary
supplements and the accurate listing of supplement ingredients, these
rules do not take full effect until 2010. And, the new rules do not
address the safety of supplement ingredients or their effects on health
when proper manufacturing techniques are used.
Most such
supplements have not been tested to find out if they interact with
medicines, foods, or other herbs and supplements. Even though some
reports of interactions and harmful effects may be published, full
studies of interactions and effects are not often available. Because of
these limitations, any information on ill effects and interactions
below should be considered incomplete.
Yohimbine and yohimbe bark can increase heart rate and raise
blood pressure. People who have high blood pressure; heart, kidney or
liver disease; and anxiety or nervous disorders should not take yohimbe
or yohimbine. Those who drink alcohol or take antidepressants,
antipsychotic drugs, methadone, certain nausea medicines, or opioid
pain medicines (such as morphine) should not use yohimbe or yohimbine.
Other potential interactions between yohimbe and other drugs and herbs
should be considered. Some of these combinations may be dangerous.
Always tell your doctor and pharmacist about any herbs you are taking.
Side effects of yohimbe bark or yohimbine include difficulty
breathing, chest pain, palpitations, anxiety, queasiness,
sleeplessness, and vomiting. Normal doses of yohimbine can cause a rise
in blood pressure. Large doses of yohimbine (40 milligrams per day or
more) can cause a drop in blood pressure and have been blamed for heart
attacks and even deaths. Yohimbine can make heart disease or blood
pressure problems worse. Less common side effects that do not usually
require medical attention include dizziness, headache, flushing,
nausea, nervousness, sweating, and tremors.
People with emotional or psychiatric problems may have
worsening of post-traumatic stress disorder, sleeplessness, and
anxiety. New onset of panic attacks or manic episodes have been
reported. Yohimbine has been linked to psychotic episodes.
Yohimbine can also act as a monoamine oxidase inhibitor
(MAOI), a type of powerful antidepressant. Foods that contain tyramine,
such as beer, red wine, liver, aged or smoked meats, and aged cheese
can raise blood pressure to dangerous levels if you eat them while
taking yohimbine.
Yohimbine or yohimbe bark should not be used by children,
elderly people, or women who are pregnant or breast-feeding. Yohimbe
bark is on the Commission E (Germany's regulatory agency for herbs)
list of unapproved herbs. This means that it is not recommended for use
because it has not been proven to be safe or effective. Relying on this
type of treatment alone and avoiding or delaying conventional medical
care for cancer may have serious health consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
Betz JM, White KD, der Marderosian AH. Gas chromatographic
determination of yohimbine in commercial yohimbe products. J AOAC Int.
1995;78:1189-1194.
Blumenthal M, ed. The
Complete German Commission E Monographs: Therapeutic Guide to Herbal
Medicines. Austin, TX: American Botanical Council; 1998.
Brinker FJ. Herb
Contraindications and Drug Interactions: With Appendices Addressing
Specific Conditions and Medicines. 2nd ed. Sandy, OR:
Eclectic Medical Publications; 1998.
Cassileth B. The
Alternative Medicine Handbook: The Complete Reference Guide to
Alternative and Complementary Therapies. New York, NY:
W.W. Norton; 1998.
Center for Drug Evaluation and Research. Personal
communication. November 1, 2005.
Summary of data for chemical selection: Yohimbe bark extract /
yohimbine. National Toxicology Program Web site.
http://ntp.niehs.nih.gov/ntp/htdocs/Chem_Background/ExSumPdf/Yohimbe.pdf.
Accessed June 9, 2008.
Ernst E, Pittler MH. Yohimbine for erectile dysfunction: a
systemic review and meta analysis of randomized clinical trials. J Urol.
1998;159:433-436.
Fetrow CW, Avila JR. Professional's
Handbook of Complementary & Alternative Medicines.
Philadelphia, PA: Lippincott Williams & Wilkins; 2004.
Gruenwald J. PDR
for Herbal Medicines. 3rd ed. Montvale, NJ: Thomson PDR;
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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. Urology.
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Lebret T, Hervé JM, Gorny P, Worcel M, Botto H.
Efficacy and safety of a novel combination of L-arginine glutamate and
yohimbine hydrochloride: a new oral therapy for erectile dysfunction. Eur Urol.
2002;41:608-613.
Management of erectile dysfunction ('05/updated '06). American
Urological Association Web site.
http://www.auanet.org/guidelines/edmgmt.cfm. Accessed June 9, 2008.
Morales A. Yohimbine in erectile dysfunction: the facts. Int J Impot Res.
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Pittler MH, Ernst E. Trials have shown yohimbine is effective
for erectile dysfunction. BMJ.
1998;317:478.
Stine SM, Southwick SM, Petrakis IL, Kosten TR, Charney DS,
Krystal JH. Yohimbine-induced withdrawal and anxiety symptoms in
opioid-dependent patients. Biol
Psychiatry. 2002;51:642-651.
Telöken C, Rhoden EL, Sogari P, Dambros M, Souto CA.
Therapeutic effects of high dose yohimbine hydrochloride on organic
erectile dysfunction. J
Urol. 1998;159:122-124.
Vogt HJ, Brandl P, Kockott G, Schmitz JR, Wiegand MH,
Schadrack J, Gierend M. Double-blind, placebo-controlled safety and
efficacy trial with yohimbine hydrochloride in the treatment of
nonorganic erectile dysfunction. Int
J Impot Res. 1997;9:155-161.
Wagner G, Saenz de Tejada I. Update on male erectile
dysfunction. BMJ.
1998;316:678-682.
Yohimbe. Drug Digest Web site.
http://www.drugdigest.org/DD/DVH/HerbsWho/0,3923,4048|Yohimbe,00.html.
Accessed June 9, 2008.
Note: This information may not cover
all possible claims, uses, actions, precautions, side effects or
interactions. It is not intended as medical advice, and should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
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