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|Systematic (IUPAC) name|
carboxylic acid methyl ester
|Trade names||Actibine, Erex, Testomar, Yocon, Yohimar, Yohimbe|
|Legal status||Prescription Only (S4) (AU) OTC|
|ATC code||G04 QV03|
|Mol. mass||354.44 g/mol (base)
390.90 g/mol (hydrochloride)
| (what is this?)
Yohimbine is a mild MAOI with stimulant and aphrodisiac effects. It is sold as 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 α2A-adrenergic receptor gene.
Yohimbine primarily acts as an antagonist of alpha-2 adrenoceptors. Additionally, it inhibits the function of monoamine oxidase enzymes, although it is not clear if it is a RIMA, MAOA, or MAOB inhibitor.
RIMAS like moclobemide (an antidepressant), does not require dietary restrictions. Many people have been supplementing with yohimbine on normal diets (containing tyramine and phenylalanine like most cheeses and fish respectively) with no adverse effects. MAOIs are normally contradicted for use with tyrosine rich food, but recently numerous companies have taken to combining yohimbine with tyrosine in their fat burners, and energy products. However, tyrosine failed to potentiate the effect of yohimbine except for somewhat augmenting the increase in DHPG.
When yohimbine are used in pharmahuasca it does not have any MAOI effects on tryptamines, eg DMT keeps being orally inactive. This suggest that yohimbine is a MAOB inhibitor. A range of cacti contain tyramine, including the Echinopsis pachanoi (syn. Trichocereus pachanoi), known as the San Pedro cactus which also contain the phenylalanine mescaline. Poly drug use with yohimbine and mescaline cactus are inconclusive.
Overdoses of yohimbine can cause priapism. Normally priapism is treated with pseudoephedrine but in conbination with MAOIs like yohimbine it can lead to hypertensive reactions. The first step in management may be blood exchange transfusion.
Medical uses 
Sexual dysfunction 
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 has been shown to be effective in the treatment of orgasmic dysfunction in men. Yohimbine has also been used to treat hypoactive sexual desire disorder (reduced libido) in women,[medical citation needed] and for sexual side effects caused by some antidepressants (SSRIs).[medical citation needed]
Yohimbine blocks the pre- and post- synaptic alpha-2 adrenoceptors. Blockade of post-synaptic alpha-2 adrenoceptors causes minor corpus cavernosum smooth muscle relaxation. In fact the majority of adrenoceptors in the corpus cavernosum are of the alpha-1 type. Blockade of pre-synaptic alpha-2 adrenoceptors facilitates the release of several neurotransmitters, in the central and peripheral nervous system, thus in the corpus cavernosum, such as Nitric Oxide and Norepinephrine. Whether Nitric Oxide released in the corpus cavernosum is the major vasodilator contributing to the erectile process, Norepinephrine has a much more powerful vasoconstricting effect by stimulation of the alpha-1 adrenoceptors on the corpus cavernosum smooth muscle. Concomitant use of an alpha-1 blocking agent will prevent constriction caused by the increased adrenergic stimulation.
- Anorgasmia or reduced libido: 5.4-16.2 mg a day 1–2 hours before sexual activity. or 5.4 mg TID (three times a day)
- Erectile dysfunction: A suggested first line treatment for mild to moderate ED are a combination of 6 mg yohimbine hydrochloride and 6000 mg arginine glutamate (50% arginine, 50% glutamic acid). Other doses of yohimbine alone to treat ED are 15 to 30 mg a day 1–2 hours before sexual activity.
Yohimbine Hydrochloride, USP—a standardized form of yohimbine—is a prescription medicine that has been used to treat erectile dysfunction. A large dose of yohimbe have caused priapism. Medical advice should be sought immediately for cases of erection beyond four hours. However, controlled studies suggest that it is not always an effective treatment for impotence, and evidence of increased sex drive (libido) is anecdotal only.
It cannot be excluded that orally administered yohimbine can have a beneficial effect in some patients with ED. The conflicting results available may be attributed to differences in drug design, patient selection, and definitions of positive response. However, generally, available results of treatment are not impressive.
Fat loss 
According to one study, oral yohimbine supplementation may actuate significant fat loss in athletes, though this study is self-reported and did not monitor caloric intake. 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.[unreliable source?][unreliable source?]
Other uses 
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.
14 mg yohimbine increases salivation.
Adverse effects 
Depending on dosage yohimbine can both lower and increase systemic blood pressure, known as vasodilation and vasoconstriction respectively; small amounts of yohimbine can increase blood pressure while large amounts can cause dangerously low pressure.
The therapeutic index of yohimbine is quite low; the range between an effective dose and a dangerous dose is very narrow. A typical dose for sexual dysfunction would be 15–30 mg, whereas 100 mg would be considered dangerous. This may also lead to the precipitation of panic disorder type reactions, heart attack and possibly death.
Hallucinations or paralysis may occur with doses greater than 40 mg. Higher doses of oral yohimbine may create numerous side effects, such as rapid heart rate, overstimulation, insomnia and/or sleeplessness. Some effects in rare cases were panic attacks, hallucinations, headaches, dizziness and skin flushing.
Precautions and contraindications 
Yohimbe bark is on the FDA list of dangerous supplements. The levels of yohimbine that are present in yohimbe bark extract are variable and often very low. Therefore, although yohimbe bark has been used traditionally to reduce male erectile dysfunction, there is not enough scientific evidence to form a definitive conclusion in this area.
In Africa, yohimbe has traditionally been used as an aphrodisiac. However, it is very important to note that while the terms yohimbine, yohimbine hydrochloride, and yohimbe bark extract are related, they are not interchangeable.
Yohimbine is an alkaloid naturally found in Pausinystalia yohimbe (Yohimbe), Rauwolfia serpentina (Indian Snakeroot), and Alchornea floribunda (Niando), along with several other active alkaloids. Yohimbine has been used as both an over-the-counter dietary supplement in herbal extract
In addition to the main active chemical, yohimbine, Pausinystalia yohimbe contains approximately 55 other alkaloids, of which 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.
Pausinystalia yohimbe is currently threatened with extinction in its native habitat due to international demand. Its conservation is difficult because the bioactivity of the tree has led many Western governments to declare it a proscribed species.
At least 14 days should elapse between discontinuation of MAOI therapy and initiation of treatment with yohimbine.
Yohimbine in combination with norepinephrine reuptake inhibitor, such as dextromethorphan, tramadol, some antidepressants and central nervous system stimulants used to treat ADHD, can cause a hypertensive crises. This is due to those drugs in combination with an a2 receptor antagonist leads to too much norepinephrine in the brain, which causes blood pressure to spike to dangerous levels.
Yohimbine in combination with modafinil is frequently associated with nausea, dangerous acute rapid heart beat, and acute increased blood pressure. Yohimbine exhibits some degree of MAOI activity while modafinil has been shown to increase levels of various monamines and therefore could result in severe risk of dangerous side effects.
Common brand names 
Yohimbine is sold as Erex, Testomar, Yocon, Yohimar, Yohimbe.
Other uses 
Sport supplements with yohimbine as the main ingredient are sold as purported energy boosters.
Yohimbine has high affinity for the α2-adrenergic receptor, moderate affinity for the α1-adrenergic, 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1F, 5-HT2B, and D2 receptors, and weak affinity for the 5-HT1E, 5-HT2A, 5-HT5A, 5-HT7, and D3 receptors. It behaves as an antagonist at α1-adrenergic, α2-adrenergic, 5-HT1B, 5-HT1D, 5-HT2A, 5-HT2B, and D2, and as a partial agonist at 5-HT1A. Its intrinsic activities at the other sites listed are unclear/unknown, but it is probably mostly antagonistic at them. Yohimbine interact with serotonin and dopamine receptors in high concentrations.
See also 
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- Verwaerde, P; Tran, MA; Montastruc, JL; Senard, JM; Portolan, G (1997). "Effects of yohimbine, an alpha 2-adrenoceptor antagonist, on experimental neurogenic orthostatic hypotension.". Fundamental & clinical pharmacology 11 (6): 567–75. PMID 9444525.
- "Yohimbe: MedlinePlus Supplements". nlm.nih.gov. November 19, 2010. Retrieved December 13, 2010.
- Adeniyi AA, Brindley GS, Pryor JP, Ralph DJ (May 2007). "Yohimbine in the treatment of orgasmic dysfunction". Asian Journal of Andrology 9 (3): 403–7. doi:10.1111/J.1745-7262.2007.00276.x. PMID 17486282.
- Saenz De Tejada, I; Kim, NN; Goldstein, I; Traish, AM (2000). "Regulation of pre-synaptic alpha adrenergic activity in the corpus cavernosum". International Journal of Impotence Research. 12 Suppl 1: S20–25. doi:10.1038/sj.ijir.3900500. PMID 10845761.
- Lebret, T.; Hervéa, J. M.; Gornyb, P.; Worcelc, M.; Botto, H. (2002). "Efficacy and Safety of a Novel Combination of L-Arginine Glutamate and Yohimbine Hydrochloride: A New Oral Therapy for Erectile Dysfunction". European Urology 41 (6): 608–613. doi:10.1016/S0302-2838(02)00175-6. PMID 12074777.
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- Yohimbe Info and Products at Bodybuilding.com
- Dhir, A; Kulkarni, SK (2007). "Effect of addition of yohimbine (alpha-2-receptor antagonist) to the antidepressant activity of fluoxetine or venlafaxine in the mouse forced swim test". Pharmacology 80 (4): 239–43. doi:10.1159/000104877. PMID 17622775.
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