Yohimbine, also known as quebrachine, is an indole alkaloid derived from the bark of the African tree Pausinystalia johimbe and from the bark of the unrelated South American tree Aspidosperma quebracho-blanco. Chemically an indole-based tetracyclic alkaloid with formula C21H26N2O3, it is commonly formulated as the hydrochloride salt for increased water solubility and administration consistency. Pharmacologically yohimbine acts primarily as an antagonist at presynaptic alpha-2 adrenergic receptors, increasing sympathetic outflow and norepinephrine release, and it shows measurable affinity at alpha-1 adrenergic sites and several monoaminergic receptors, which contributes to its cardiovascular and central nervous system effects. It is a veterinary drug used to reverse xylazine sedation in animals and in clinical and research contexts has been investigated for applications including treatment-resistant erectile dysfunction, experimental models of anxiety, and metabolic studies; oral bioavailability is variable due to first-pass hepatic metabolism and formulations and dosing require careful titration.
Parent: Yohimbine
![9-Methyl-9H-pyrido[3,4-b]indole](https://veeprho.com/wp-content/uploads/2024/11/VE0022227-9-Methyl-9H-pyrido-3-4-b-indole.png "9-Methyl-9H-pyrido[3,4-b]indole")
Parent: Yohimbine
Pharmaceutical grade yohimbine hydrochloride is typically manufactured and tested to meet strict assay and related-substance limits with assay purity commonly greater than 98% and total related impurities kept below established ICH thresholds, for example individual related substances often specified below about 0.5 to 1.0% and total impurities below about 2.0% depending on the monograph or specification. Crude botanical extracts have a variable alkaloid profile; yohimbine content in raw bark material is source dependent and frequently reported in low single-digit percent ranges by dry weight, while co-occurring indole alkaloids such as rauwolscine (alpha-yohimbine), corynanthine, 17-hydroxyyohimbine and ajmalicine may appear at lower relative abundances and are the principal related compounds monitored by HPLC-UV and LC-MS impurity profiling. Typical quality control approaches include HPLC retention-time matching, mass spectrometric confirmation for related substances, and limits for residual solvents and heavy metals consistent with regulatory guidance.
Yohimbine is used in veterinary practice to reverse alpha-2 agonist sedation such as xylazine and in human medicine and research it has been used for erectile dysfunction, studied for potential effects on body composition and mood, and employed experimentally to probe adrenergic and stress-response pathways; clinical use requires physician oversight because of cardiovascular and neuropsychiatric effects.
No, Yohimbine is an alpha-2 adrenergic receptor antagonist, not an agonist; by blocking presynaptic alpha-2 receptors it increases norepinephrine release and sympathetic tone.
Daily use carries risk and should only be considered under medical supervision; adverse effects can include increased heart rate, elevated blood pressure, anxiety, dizziness and interactions with antidepressants, stimulants and antihypertensives, so individualized risk assessment, dose titration and monitoring are recommended.
No, Yohimbine is an indole alkaloid, chemically and biologically distinct from steroid compounds.
