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Yohimbe Bark
Pausinystalia yohimbe
TRADE NAMES
Yohimbe, Yohimbe Super Potent, Yohimbized 1000, Yocon
Tablets, Actibine, Aphrobine, Testomar, Yohimex, Super
Yohimbe Plus, Yohimbe Power Max 1500, Yohimbe Power
Max for Women, Yohimbe Power Max 2000.
DESCRIPTION
Medicinal Parts: The medicinal part is the bark.
Flower and Fruit: The inflorescence consists of racemes of
yellow blooms.
Leaves, Stem and Root: The evergreen tree grows up to 30 m
in height. The bark is gray-brown, fissured and split, and is
often spotted. The inner fracture is reddish brown and
grooved. The leaves are oblong or elliptical.
Characteristics: The taste is bitter, and the plant is odorless.
Habitat: The plant grows in the jungles of west Africa,
Cameroon, Congo and Gabon.
Production: Yohimbe bark consists of the dried bark of the
trunk and/or branches of Pausinystalia yohimbe.
ACTIONS AND PHARMACOLOGY
COMPOUNDS
Indole alkaloids (2.7-5.9%): including among others yohim-
bine (quebrachine) and its stereoisomers alpha-yohimbine
(rauwolscine), beta-yohimbine, and allo-yohimbine. Includ-
ing also, ajamalicine, dihydroyohimbine, corynantheine,
dihydrocorynantheine, corynanthine (rauhimbin)
Tannins
EFFECTS
Alpha 2-adrenergic Antagonist/Norepinephrine Release:
Rauwolscine is a selective alpha 2-adrenergic receptor
antagonist. Yohimbine increases plasma norepinephrine
(NE) levels by stimulating the rate of norepinephrine release
from sympathetic nerves (alpha 2-adrenergic antagonist)
(Murburg, 1991). Plasma concentrations of 3-methoxy-4-
hydroxyphenylglycol (MHPG), the major central nervous
system metabolite of NE, also increases with yohimbine
(Piletz, 1998). Central noradrenergic stimulation of yohim-
bine results in the enhancement of recall and recognition of
emotional material (O'Carroll, 1999).Analgesic Effects: Yohimbine significantly enhanced the
overall analgesic effect of morphine with postoperative
dental pain (Gear, 1995).Clonidine Antagonism: Traditionally, yohimbine was
thought to reverse the therapeutic effects of clonidine. One
study demonstrated yohimbine reversed sedation and short-
ened the duration of analgesia associated with clonidine
administered postoperatively. There was no effect on hypo-
tension and bradycardia related to clonidine administration
with yohimbine (Liu, 1993).Epinephrine Effects: Yohimbine causes an increase in
epinephrine release from the adrenals and results in a dose-
dependent increase in plasma epinephrine (Murburg, 1991).
Improves Sexual Function: Because of the alpha-2 adrener-
gic blockade, the drug may be an effective treatment for
sexual side effects, such as decrease libido and decreased
sexual response, caused by selective serotonin reuptake
inhibitors (Jacobsen, 1992; Hollander, 1992). There was no
therapeutic response to yohimbine in women with hypoac-
tive sexual desire (Piletz, 1998).Cardiovascular/Pressor Effects: Yohimbine given in moder-
ate doses increases systolic blood pressure in patients with
orthostatic hypotension due to primary autonomic failure
(Jordan, 1998). Yohimbine-induced enhancement of sympa-
thetic tone in patients with neurally mediated syncope
improves orthostatic tolerance (Mosqueda-Garcia, 1998).Salivary Effects: Yohimbine (18 mg daily) increases salivary
flow in patients treated with psychotropic drugs (tricyclic
antidepressants or neuroleptics) suffering from xerostomia
(Bagheri, 1997).Miscellaneous Effects: Through enhancing inhibitory sympa-
thetic input, yohimbine attenuates increases in colonic tone
(Bharucha, 1997).CLINICAL TRIALS
Non-organic Erectile DysfunctionA double-blind, placebo-controlled clinical trial was con-
ducted to determine the safety and efficacy of yohimbine
hydrochloride in the treatment of nonorganic erectile dys-
function. Eighty-three patients were included in the inten-
tion-to-treat analysis. Yohimbine (10 mg three times daily)
was administered orally for eight weeks. Subjective criteria
included improvement in sexual desire, sexual satisfaction,