Also Known As: Yohimbine, Yohimbe, Pausinystalia yohimbe, Yohimex, Aphrodyne
Yohimbine is an alkaloid with stimulant and aphrodisiac effects found naturally in Pausinystalia yohimbe (Yohimbe). It is also found naturally in Rauwolfia serpentina (Indian Snakeroot), Alchornea floribunda (Niando), along with several other active alkaloids. Yohimbine has been used as both an over-the-counter dietary supplement in herbal extract form and prescription medicine in pure form for the treatment of sexual dysfunction. Yohimbine was explored as a remedy for type 2 diabetes in animal and human models carrying polymorphisms of the Î±2A-adrenergic receptor gene.
The NIH states that yohimbine hydrochloride is the standardized form of yohimbine that is available as a prescription medicine in the United States, and has been shown in human studies to be effective in the treatment of male impotence.
Yohimbine Hydrochloride, USP—a standardized form of yohimbine—is a prescription medicine that has been used to treat erectile dysfunction. Controlled studies suggest that it is not always an effective treatment for impotence, and evidence of increased sex drive (libido) is anecdotal only.
Yohimbine blocks the pre- and post-synaptic alpha-2 adrenoceptors. Blockade of post-synaptic alpha-2 adrenoceptors leads to minor corpora cavernosa smooth muscle relaxation. In fact the majority of adrenoceptors in the corpora cavernosa are alpha-1. Blockade of pre-synaptic alpha-2 adrenoceptors leads to increased release of neurotransmitters in the central nervous system and in the corpora cavernosa penis such as nitric oxide, noradrenaline, and dopamine. Whether nitric oxide released in the corpora cavernosa has a relaxing effect, noradrenaline has a much powerful constricting effect by stimulating the unblocked alpha-1 adrenoceptors. Concomitant use of an alpha-1 blocking agent will prevent constriction caused by the increased adrenergic stimulation.
Pausinystalia Yohimbe (Yohimbe) doesn't contain just yohimbine. It contains around 55 other alkaloids and yohimbine accounts for 1% to 20% of total alkaloids. Among them corynanthine is an alpha-1 adrenoceptor blocker. Hence the use of Yohimbe extract in sufficient dosages may provide concomitant alpha-1 and alpha-2 adrenoceptors blockade and thus may better enhance erections than yohimbine alone.
Yohimbine has been shown to be effective in the reversal of sexual satiety and exhaustion in male rats. Yohimbine has also been shown to increase the volume of ejaculated semen in dogs, with the effect lasting at least five hours after administration. Yohimbine has been shown to be effective in the treatment of orgasmic dysfunction in men.
According to one study, oral yohimbine supplementation may actuate significant fat loss in athletes. Numerous bodybuilding supplement companies sell formulations of yohimbine for transdermal delivery to effect a local reduction of adipose tissue, although the experimental evidence for its efficacy is limited.
Yohimbine 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.
The addition of yohimbine to fluoxetine or venlafaxine has also been found to potentiate the antidepressant action of both of these agents.
Yohimbine has been used to facilitate recall of traumatic memories in the treatment of post traumatic stress disorder (PTSD). Use of yohimbine outside therapeutic settings may not be appropriate for persons suffering from PTSD. In pharmacology, yohimbine is used as a probe for α2-adrenoceptor. In veterinary medicine, yohimbine is used to reverse anesthesia from the drug xylazine in small and large animals.