Yohimbine

Yohimbine
Clinical data
Pronunciation	/joʊˈhɪmbiːn/
Other names	Quebrachine
Routes of; administration	By mouth
Drug class	α2-Adrenergic receptor antagonist
ATC code	G04BE04 (WHO) QV03AB93 (WHO);
Legal status
Legal status	AU: S4 (Prescription only); CA: ℞-only; US: Unscheduled;
Pharmacokinetic data
Bioavailability	7-86% (mean 33%)
Elimination half-life	0.25–2.5 hours
Excretion	Urine (as metabolites)
Identifiers
	IUPAC name 17α-hydroxyyohimban-16α-carboxylic acid methyl ester;
CAS Number	146-48-5 ;
PubChem CID	8969;
IUPHAR/BPS	102;
DrugBank	DB01392 ;
ChemSpider	8622 ;
UNII	2Y49VWD90Q;
KEGG	D08685 ;
ChEBI	CHEBI:10093 ;
ChEMBL	ChEMBL15245 ;
CompTox Dashboard (EPA)	DTXSID9040130 ;
ECHA InfoCard	100.005.157
Chemical and physical data
Formula	C21H26N2O3
Molar mass	354.450 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES [H][C@@]15CC[C@H](O)[C@H](C(=O)OC)[C@@]1([H])C[C@@]4([H])c3[nH]c2ccccc2c3CCN4C5;
	InChI InChI=1S/C21H26N2O3/c1-26-21(25)19-15-10-17-20-14(13-4-2-3-5-16(13)22-20)8-9-23(17)11-12(15)6-7-18(19)24/h2-5,12,15,17-19,22,24H,6-11H2,1H3/t12-,15-,17-,18-,19+/m0/s1 ; Key:BLGXFZZNTVWLAY-SCYLSFHTSA-N ;
	(verify)

Yohimbine, also known as quebrachine, is an indole alkaloid derived from the bark of the African tree Pausinystalia johimbe (yohimbe); also from the bark of the unrelated South American tree Aspidosperma quebracho-blanco. Yohimbine is an α₂-adrenergic receptor antagonist, and has been used in a variety of research projects. It is a veterinary drug used to reverse sedation in dogs and deer.

While yohimbine behaves as an aphrodisiac in some mammals, it does not do so in humans. It has been prescribed as a treatment for erectile dysfunction, although its reported clinical benefits were modest and it has largely been superseded by the PDE5 inhibitor class of drugs. Substances that have purported to be extracts from the yohimbe tree have been marketed as dietary supplements for various purposes, but they contain highly variable amounts of yohimbine, if any; no published scientific evidence supports their efficacy.