RESEARCH MONOGRAPH · KDC-MN-260

Yohimbine

May 9, 2026 Kodiac biolabs Research Revised May 30, 2026 3 min read

Our opinion on this compound

65/100

Alpha-2 antagonist with a useful research profile and a long history of being oversold to consumers

Yohimbine is the textbook alpha-2 adrenergic antagonist, and depending on which subfield you're in it's either a useful research tool or a tired supplement gimmick. Both descriptions are accurate. The indole alkaloid from Pausinystalia johimbe is a competitive antagonist at alpha-2 receptors with some affinity for 5-HT1A, 5-HT1B, and D2 sites at higher exposures. As a clean alpha-2 probe it's actually pretty good; at higher doses the polypharmacology gets messy fast.

What we like for research use is the mirror-image relationship to clonidine. If clonidine reduces locus coeruleus output by agonizing the autoreceptor, yohimbine does the opposite, releasing the brake and producing a noradrenergic surge. That makes it a useful tool for panic-induction paradigms (the Charney lab's classic yohimbine challenge work in PTSD and panic disorder), for sympathetic-activation studies, and for probing autonomic reactivity in clinical research contexts.

The panic-challenge work is genuinely interesting. Charney and colleagues at Yale used controlled yohimbine challenges in the 80s and 90s to show that PTSD patients have exaggerated noradrenergic responses, which was foundational evidence for the noradrenergic dysregulation model of trauma-related disorders. That literature is one of the better uses of yohimbine in human neuroscience.

What we dont like is the supplement industry treatment. Yohimbine as a fat-loss adjuvant is mostly thin signal stacked on top of caffeine-driven thermogenesis, and the pharmacokinetics are wildly variable between people because of CYP2D6 polymorphism. The hypertensive and anxiogenic responses at higher exposures are real and unpredictable enough that the supplement-store framing significantly understates the risk profile.

Sourcing is where it gets complicated. Yohimbe bark extract and yohimbine hydrochloride are very different products. Bark extract is a mixture of alkaloids (yohimbine, corynanthine, rauwolscine, and others) with substantial batch variability; the hydrochloride is a defined chemical entity and what you want for research. Vendor verification matters; mislabeled rauwolscine-dominant material has shown up in research catalogs.

Mechanism is well-characterized, evidence base is solid for what it's used for in noradrenergic challenge work, supplement claims are weak. Reliability depends on what you're measuring; for autonomic readouts it's predictable, for anything weight-loss-related it's a coin flip. Honest take: useful tool, hyped product.

Evidence: 65
Mechanism: 82
Reliability: 65
Safety: 55
Sourcing: 65
Value: 70
Signal: 60
Staying power: 60

Plain-language summary Intrigue 55 / 100

Yohimbine is an alkaloid extracted from the bark of an African tree (Pausinystalia johimbe), used historically as an aphrodisiac. Pharmacologically it is an alpha-2 receptor blocker, which means it does the opposite of clonidine: it ramps up the sympathetic nervous system, raising noradrenaline release. At low doses it can produce alertness, anxiety, and a small erectile-function benefit; at higher doses it triggers panic-like states and is used in research as a deliberate panic challenge. Sold widely as a fat-loss and pre-workout supplement, with mixed clinical evidence. The pressor and anxiogenic effects make it dangerous for people with cardiovascular disease or anxiety disorders. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

Selective alpha-2 adrenergic antagonist

An indole alkaloid alpha-2 adrenergic antagonist from Pausinystalia johimbe; the canonical pharmacological probe for noradrenergic activation.

Abstract

Yohimbine (17-alpha-hydroxy-yohimban-16-alpha-carboxylic acid methyl ester; CAS 146-48-5; molecular formula C21H26N2O3; molecular weight 354.45) is an indole alkaloid isolated from the bark of Pausinystalia johimbe (Rubiaceae) and from Rauwolfia species. The compound is a selective alpha-2 adrenergic antagonist (Ki approximately 1 to 5 nM) with secondary 5-HT1A partial agonism (Ki approximately 100 nM); selectivity for alpha-2 over alpha-1 is approximately 50-fold. Pharmacologically, yohimbine increases central noradrenergic outflow by blocking presynaptic autoinhibition, producing anxiety, increased blood pressure, mydriasis, and tachycardia. Used in clinical research as a provocation test for panic disorder (where vulnerability to alpha-2 antagonism predicts panic susceptibility) and as a positive control in studies of noradrenergic regulation. Folk use as an aphrodisiac for erectile dysfunction has limited supporting evidence. Plasma half-life is approximately 0.6 hours. Used as the canonical alpha-2 antagonist in academic pharmacology.

Mechanism of action

Selective alpha-2 adrenergic antagonism (~50-fold over alpha-1); secondary 5-HT1A partial agonism. Increases central noradrenergic outflow.

Reported research dose ranges

Research 5 to 20 mg in the published literature; clinical (off-label ED) 5 mg in the published literature. Rodent studies 0.5 to 5 mg/kg.

References

Goldberg MR, Robertson D. Yohimbine: a pharmacological probe for study of the alpha-2 adrenoreceptor. Pharmacol Rev 1983.
Charney DS, et al. Noradrenergic function in panic anxiety: effects of yohimbine in healthy subjects and patients with agoraphobia and panic disorder. Arch Gen Psychiatry 1984.
Tam SW, et al. Yohimbine: a clinical review. Pharmacol Ther 2001.

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KDC-MN-260

The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.

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Yohimbine

Abstract

Mechanism of action

Reported research dose ranges

References

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Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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