|
Yohimbine
Yohimbine is an alkaloid originally found in the bark of the Yohimbe tree that
grows in southern Africa. It has been used as an aphrodisiac and to treat
sexual dysfunction for centuries but has gained recent notoriety as a fat loss
supplement. Numerous recent studies have indicated that yohimbine is effective
at blocking alpha adrenoreceptors, something that as will be detailed later is
highly efficient at promoting fat loss. For this reason yohimbine has become
quite popular and relatively widely available.
The primary mechanism by which yohimbine works is by blocking alpha
adrenoreceptors. These receptors, when stimulated, prevent the release of
norepinephrine. Norepinephrine is one of the primary lipolytic hormones in the
body and stimulates the alpha and beta adrenoreceptors. There are several
feedback mechanisms that cause norepinephrine release to be stunted. Yohimbine
works to combat this. Stimulation of the beta adrenoreceptors, via
norepinephrine, can cause lipolysis (the break down of fat). By blocking the
alpha adrenoreceptors more norepinephrine is able to be released and lipolysis
can continue.
The reason why the inhibition of the alpha adrenoreceptor works so well in
terms of promoting fat loss is that it is responsible for regulating lipolysis
during the times that are bodies are at rest and not during strenuous
activity, i.e. the majority of the day. Therefore by stimulating the mechanism
that allows us to burn fat during most of the day we become even more
efficient at burning fat. Interestingly enough it also is true that the
majority of males have a higher ratio of alpha adrenoceptors in the body fat
that they hold in their abdominal areas, while women have a higher ratio in
the body fat around their hips and thighs. This would bode well for those
individuals having trouble reducing their fat deposits in those areas that are
seemingly universal among the sexes.
Other than the effects that yohimbine has on lipolysis, it has also been
successfully used to treat sexual dysfunction in men (1) and can help with
sexual arousal in women if combined with L-arginine glutamate (2) as it is a
vasodilator. It has also been shown to slightly raise testosterone levels in
males (3), however this rise is negligible. There are also anecdotal reports
by some users that they experience an increased "pump" in the gym while using
the supplement, however of course there is no scientific research or studies
to back up this assertion.
Use and Dosing for Yohimbine>
Clinically, doses of approximately .2mg per kilogram per day have been shown
to be effective is reducing body fat for both men and women (4, 5). This type
of dosing should also result few side effects for the user. The half life of
yohimbine is only about one to two hours, however because the half life of the
metabolite 11-hydroxy-yohimbine is six to eight hours (and this metabolite has
a similar action as yohimibine itself) a user should only have to take doses
of the supplement two or three times per day to see the full effects.
It is recommended that yohimbine be taken on an empty stomach as if it was to
be taken with meals this may reduce it's lipolytic effects (5). Of course, as
is discussed below, due to some of the side effects associated with yohimbine
it is advisable that a user do not take it close to when they are going to
sleep as it can cause insomnia.
In terms of length of use there is no direct information stating that
yohimbine becomes less effective the longer a user administers it, however
anecdotally most users report that the effects of the compound tend to
dissipate over time and doses must be increased to continue at previous
levels. This would seem to indicate that some receptor down-regulation, which
is likely to occur.
For this reason it would seem obvious that users need to cycle their use of
yohimbine. Since there are no studies suggesting the most efficient way to do
this, it is primarily up to the user to experiment with the most effective
method to be used.
Risks and Side Effects while using Yohimbine>
The side effects associated with yohimbine are mostly related to the elevated
levels of norepinephrine that it causes. Anxiety, increased heart rate and a
rise in blood pressure are all side effects that are common at higher doses,
with insomnia be related to these.
Other possible side effects include dizziness, anxiety, hyperstimulation, and
nausea among others (6). There are conflicting studies that suggest that in
some cases yohimbine can cause antidiuresis, decreased frequency of urination
(7) or an increased frequency of urination (6). The reason for the discrepancy
is not explained in the scientific literature, but there could be numerous
variables in the studies that would be cause for this difference in the
information.
Also due to yohimbine being able to downregulate your body's response to
norepinephrine many male users will complain of not being able to achieve
orgasm during sexual activity. This is somewhat ironic in the fact that
yohimbine can help with erectile difficulties, but can cause problems in
"completing the act".
Of course, with all supplements like yohimbine it is recommended that a user
begin taking a much smaller dosage than is required to begin with so that they
are able to gage their reaction to it. Many will find that they are able to
use doses far smaller than thought and achieve good results. As well, one does
not want to start off with high doses if the side effects are unbearable. All
side effects associated with yohimbine dissipate once administration of the
supplement ceases.
As always, any potential drug interactions should be discussed with a doctor.
It should be noted however that yohimbine is often prescribed to individuals
who are taking selective serotonine re-uptake inhibitors and suffer from
erectile dysfunction as a side affect of this medication. It is also often
advised that yohimbine can cause adverse reactions if combined with monoamine
oxydase inhibitors (MAOIs). They same is true of some anti-depressant
medications. Again, if you are using other types of medications consult with
your doctor before beginning yohimbine.
References
1. Tam SW, Worcel M, Wyllie M. Yohimbine: a clinical review.
Pharmacol Ther. 2001 Sep;91(3):215-43
2. Meston CM, Worcel M. The effects of yohimbine plus L-arginine glutamate on
sexual arousal in postmenopausal women with sexual arousal disorder. Arch Sex
Behav. 2002 Aug;31(4):323-32
3. Guay AT, Spark RF, Jacobson J, Murray FT, Geisser ME. Yohimbine treatment
of organic erectile dysfunction in a dose-escalation trial. Int J Impot Res.
2002 Feb;14(1):25-31
4. Berlan M, Galitzky J, Riviere D, Foureau M, Tran MA, Flores R, Louvet JP,
Houin G, Lafontan M. Plasma catecholamine levels and lipid mobilization
induced by yohimbine in obese and non-obese women. Int J Obes. 1991
May;15(5):305-15
5. Galitzky J, Taouis M, Berlan M, Riviere D, Garrigues M, Lafontan M. Alpha
2-antagonist compounds and lipid mobilization: evidence for a lipid mobilizing
effect of oral yohimbine in healthy male volunteers. Eur J Clin Invest. 1988
Dec;18(6):587-94
6. Webber R. Erectile dysfunction. Clinical Evidence. 2003 (10): 1003�1011
7. Farjam A, Greven J. Effects of the alpha 2-adrenoceptor antagonists
yohimbine and idazoxan on kidney function in intact and diabetes insipidus
rats. Urol Int. 1989;44(5):255-9.
Books and Courses
|
Great Websites
|
Excellent Stores
|
Recipe Cook Books
|
|
|
