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Traditional uses:
Yohimbe has been used for centuries
in African folk medicine to treat leprosy, coughs, treat fevers,
as a local anesthetic, sexual aphrodisiac, etc. African tribal men
would often chew on the bark prior to going to battle to increase
their strength; however, its most popular use has been as an aphrodisiac
and to improve erections.
Physiology:
While Viagra tends to be the medication of choice for erectile dysfunction,
Yohimbe has proven to be an overall better remedy for improving
both psychological well being of an individual and the erectile
dysfunction. In order to understand the mechanism of action of Yohimbe,
we must go over some physiology 101:
A large percentage of incurred
physiological processes are not controlled voluntarily by an individual.
These processes are controlled by the autonomic nervous system.
The autonomic nervous system consists of two systems, the sympathetic
and the parasympathetic nervous system. These two divisions of the
nervous system counteract the action of the other to control our
bodily functions.
More specifically, the sympathetic nervous system controls our "fight"
and "flight" processes, while the parasympathetic system controls
our "feed" and "breed" processes. The sympathetic division is responsible
for the body's reaction to stress factors. When the sympathetic
system is active, blood pressure, heart rate and respiration rate
increase, blood vessels to the heart dilate, blood flow increases
to the muscles, and pupils dilate. Think of a lion preparing to
fight his hair is standing on end (giving the impression that he
is larger), pupils are dilated, heart rate increases, and breathing
becomes rapid. This reaction is accompanied by a constriction of
arterial blood vessels and a decrease in the blood flow to the digestive
organs and reproductive organs (an erection on a lion during a fight
would be an unwanted obstacle, not to mention a vulnerable target
for the opposition).
When stressful situations subside, parasympathetic nervous
system will slow the heart rate and decrease blood pressure, moderate
the breathing process, induce salivation, and increase blood flow
to the digestive and reproductive organs. The signals from the sympathetic
and the parasympathetic nervous system are transmitted via neurotransmitters
that signal specific receptors. The neurotransmitter active on the
sympathetic pathway is norepinephrine while parasympathetic pathway
uses acetylcholine.
Yohimbe blocks the receptor sites
for the neurotransmitter norepinephrine. Specifically, Yohimbe blocks
the alpha-2-adrenergic receptors thus decreasing the action of the
sympathetic nervous system so the parasympathetic system can prevail.
By blocking the signals from the sympathetic system the parasympathetic
system input prevails resulting in more blood flow to the female
erectile organs. Secondary to the increased parasympathetic input
there is also an increase in other parasympathetic activities including
the digestive process.
In order to understand
why the interference with alpha-2 adrenergic receptors work to facilitate
erections, an individual must understand that during the normal
flaccid genital state the norepinephrine is almost permanently docked
to the alpha-2 adrenergic receptors. In order to achieve an erection
there must be a decrease in the stimulation of alpha-2 adrenergic
receptors. Yohimbe, by blocking the norepinephrine receptors (alpha-2-adrenergic
receptors), increases the in freely circulating norepinephrine.
The additional norepinephrine (adrenaline) subsequently acts as
a hormone to exert the typical adrenergic effect on the heart, resulting
in an increased heart rate, possible palpitations, etc. The increase
norepinephrine also causes a reaction similar to amphetamines; men
experience an increase sense of alertness sexual arousal.
This makes Yohimbine
very unique in that the herb has a dual aphrodisiac function: First
the herb improves sexual function by displacing hormonal epinephrine
from alpha-2 adrenergic receptors in the pelvic area by
increasing blood flow to the female erectile organs. Second the
herb, increases the levels of free norepinephrine which subsequently
results in an increase sense of alertness and sexual arousal.
Clinical Studies:
There have been numerous clinical studies that confirm Yohimbe’s
effectiveness. For example, in the February 1998 issue of the Journal
of Urology, researchers from the University of Exeter Medical School
in England surveyed clinical trials involving the herb and concluded
that Yohimbine should be used in the first line of treatment for
erectile dysfunction. The benefits of Yohimbe far outweigh the risks
associated with the herb.
Additional clinical studies have shown that Yohimbe to be effective
in up to 80% of men with erectile dysfunction. These results rival
the clinical results of Viagra that show a positive effect in some
75%-83% of the population tested. Yohimbe was shown to be most effective
in men who suffer from impotence secondary to psychological, vascular
or diabetic in origin.
The herbal supplement did not produce significant improvement in
males with impotence caused by organic nerve damage (which is only
attributed to a small percent of those individuals with impotence).
Yohimbe was also shown to increase sexual stamina and prolong erections
in men who are free from the complications of impotence.
In addition, the promising value of Yohimbe is not only the herbs
role as a treatment for erectile dysfunction but its power to enhance
sexuality in healthy subjects. Yohhimbe is also prescribed as an
effective weight loss supplement. Lise Alschuler M.D., medical director
at Bastyr University in Washington stated that “Yohimbe is
my number one choice for weight loss. I start with a very small
dose and the gradually increase the intake while monitoring the
patient’s tolerance levels.”
Modern day uses:
Today, Yohimbe is not only prescribed by physicians and herbal specialist
for erectile dysfunction but for the following positive benefits:
- Effective in restoring potency in diabetic and heart patients
who suffer from impotency
- Has been used in traditional medicine to treat angina and hypertension
- Effective weight loss agent
- Increase overall stamina and endurance
- Promotes generalized feeling of well being
Precautions and/or side effects:
Individuals with preexisting medical conditions should consult with
their physician particularly if they are taking prescription or
over-the-counter-medications or supplements. Women who are pregnant
or breast feeding and children should also consult with there physician
prior to taking any new supplements. Yohimbe should not be taken
with food or drinks that contain a high amount of tyramine, i.e.
avoid aged cheese; aged or cured meats (e.g., air-dried sausage);
any potentially spoiled meat, poultry, or fish; broad (fava) bean
pods; Marmite concentrated yeast extract; sauerkraut; soy sauce
and soy bean condiments; and tap beer. Tyramine is a sympathomimetic
agent that can potentate the side effects of the supplement.
Yohimbe should be taken with
caution, the herb should not be consumed by individuals who are
currently taking antidepressants, sedatives, certain antihistamines,
stimulants and/or hypertensive medications. Yohimbe is considered
to be a short term MAO inhibitor; therefore, individuals with a
history of hypertension should use caution prior to taking the herb.
Yohimbe may induce excessive adrenal or sympathetic nerve stimulation,
anxiety, panic attacks, irritability, sweating, flushing, hypertension,
headaches, dizziness, nausea, skin flushing, frequent urination,
water retention, increased body temperature, upset stomach, etc.
Yohimbe is also reported to have mild hallucinogenic properties
in some individuals. These effects include audio and visual hallucinations,
and feelings of euphoria. Most of the side effects mentioned above
occur when individuals take the supplement in higher than recommended
dose.
Most physicians recommend taking Yohimbine on
a daily basis to
avoid the side effects of nervousness and possible agitation. Practically
all hormones have the effect of inhibiting their own production,
usually via what is called a negative feedback system. (Messages
are carried through blood plasma to the hypothalamus-pituitary systems
when there is an increase in neurotransmitters to limit their production
in the future.) The adrenal hormones or neurotransmitters epinephrine
and norepinephrine are no exception. |