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BHuman cohort / observational
CardiovascularAnxietyHigh riskCardiotoxicNeuropsychiatric

Yohimbine HCL

Yohimbine

Yohimbine HCl is an indole alkaloid and alpha-2 adrenoceptor antagonist derived from the bark of Pausinystalia johimbe. By blocking presynaptic alpha-2 receptors it triggers a surge of noradrenaline (a hyperadrenergic/sympathomimetic state), which is the basis for its historical prescription use in erectile dysfunction and its unapproved use in supplements marketed for fat loss and physique. The same noradrenergic surge drives its dangers. Documented human harms include severe hypertension, tachycardia, hypertensive emergency, intracranial hemorrhage, seizures, panic attacks, and death from acute intoxication. There is no conclusive human evidence that yohimbine improves body composition, athletic performance, or physique, and a controlled trial of high-dose oral yohimbine found no effect on body fat or fat distribution. Toxicity is dose-dependent and unpredictable because oral bioavailability varies enormously between individuals and supplement products are frequently mislabeled. It is not an anabolic or hormonal agent. This is a reference summary, not medical advice; anyone using or considering it should work with a clinician.

Clinical readoutPED-adjacent · stimulant
Hepatic strainNone
CardiovascularHigh
HPTA suppressionNone
Half-life
Short and variable
Route
Oral
Evidence
B
Active
Short-acting
1·t½2·t½3·t½4·t½5·t½
Illustrative single-compartment washout · each mark = one half-life · t½ ≈ Short and variable. In healthy men given 10 mg orally, mean plasma elimination half-life was ~0.6 h (Owen 1987); in acute high-dose overdose the apparent half-life was longer (~2 h). Oral bioavailability is highly variable between individuals.
Pharmacology

Mechanism of action

Yohimbine is a competitive antagonist at pre- and postsynaptic alpha-2 adrenergic receptors. Blockade of inhibitory presynaptic alpha-2 autoreceptors removes the negative feedback on noradrenaline release, increasing central and peripheral sympathetic (noradrenergic) tone and raising plasma catecholamines and the noradrenaline metabolite MHPG. In adipose tissue, antagonism of antilipolytic alpha-2 receptors is the proposed rationale for a lipolytic effect (preclinical/mechanistic), but this has not translated into demonstrated fat loss in controlled human trials. In erectile tissue, increased noradrenergic and central sympatholytic activity is the proposed mechanism for its pro-erectile effect. It has weaker activity at 5-HT and dopaminergic sites.
Kinetics

Pharmacokinetics

Half-life

Short and variable. In healthy men given 10 mg orally, mean plasma elimination half-life was ~0.6 h (Owen 1987); in acute high-dose overdose the apparent half-life was longer (~2 h). Oral bioavailability is highly variable between individuals.

Active duration

Short-acting; sympathomimetic effects roughly parallel the brief plasma exposure (single-dose autonomic effects observed over a few hours), though clinical effect duration is not precisely defined.

Route

Oral (tablet/supplement) is the common route; intravenous yohimbine has been used only in research/challenge settings. Absorption is rapid but reduced by a high-fat meal.

Metabolism & clearance

Eliminated primarily by hepatic metabolism. Renal excretion of unchanged drug is negligible (~0.35% of dose in 24 h urine), and only ~20% partitions into red blood cells. This context is for understanding washout and clearance, not for evading testing.

For monitoring and washout planning, not drug-test evasion.

Reported effects

Physiological & performance effects

  • Sympathomimetic / hyperadrenergic activation: increased noradrenaline release, rise in plasma catecholamines and MHPG, and dose-related increases in blood pressure and respiratory rate (healthy volunteers).
  • Modest efficacy for erectile dysfunction as monotherapy versus placebo in a meta-analysis of randomized trials (odds ratio ~3.85).
  • No demonstrated benefit for body composition, physique, or exercise/physical performance in humans; a 6-month RCT of high-dose oral yohimbine (peak 43 mg/day) showed no effect on body weight, body fat, or fat distribution.
  • Increased subjective anxiety/arousal and, in susceptible individuals, panic; used experimentally as a noradrenergic 'panic probe'.
  • Proposed lipolytic effect via alpha-2 blockade in fat cells is preclinical/mechanistic and not supported by controlled human physique outcomes.
Safety

Adverse effects by system

Cardiovascular

Well documented in humans: dose-related increases in blood pressure and heart rate; overdose has produced hypertensive emergency (e.g., BP 259/107 mmHg, HR 140), and a single supplement dose has been temporally associated with intracranial hemorrhage. This is the primary organ system of concern.

Hepatic

No established direct hepatotoxicity signal in the human literature; no adequate human data specifically evaluating liver injury. Assume unknown rather than safe.

Endocrine / HPTA

Not a hormonal/anabolic agent; no evidence of gonadal (HPTA) axis suppression. It does acutely raise catecholamines and sympathetic tone (an endocrine/autonomic stress-type response); no adequate data show meaningful effects on testosterone, LH/FSH, or thyroid axes.

Reproductive

Used therapeutically for erectile dysfunction; priapism is a theoretical/rare concern with pro-erectile agents. No adequate human data on fertility or other adverse reproductive effects; avoid in pregnancy given lack of safety data and sympathomimetic activity.

Neuropsychiatric

Anxiety, agitation, irritability, and panic attacks are documented; yohimbine reliably provoked panic attacks in a substantial fraction of PTSD patients and increases anxiety in susceptible people. Can worsen anxiety, panic, and PTSD symptoms.

Renal

Renal elimination of the drug is negligible and no direct nephrotoxicity is established; however, severe drug-induced hypertension could indirectly threaten end-organs including the kidney. No adequate human data on direct renal toxicity.

Hematologic

No known clinically significant hematologic toxicity and no adequate human data suggesting one.

Dermatologic

Flushing and diaphoresis (sweating) reported in intoxication case series; piloerection possible. No serious dermatologic toxicity established.

Recovery

HPTA suppression & recovery

Suppression: None expected — not a hormonal agent

Yohimbine is not a SERM, aromatase inhibitor, anabolic steroid, or other hormonal compound and is not known to suppress the hypothalamic-pituitary-gonadal (HPTA) axis, so no post-cycle recovery framing applies. If HPTA concerns exist from concurrent hormonal agents (which must be managed as single-SERM at most, never dual-SERM), those are separate from yohimbine and should be evaluated and managed by an endocrinologist rather than self-directed.

Bloodwork & vitals

Monitoring

Recommended labs & checks
Baseline and on-treatment blood pressure and heart rate (home and clinical measurement)Baseline cardiovascular evaluation (including ECG) in anyone with cardiac risk factors before useBasic metabolic/renal panel and liver function tests at baseline given supplement adulteration risk and lack of safety dataMedication/supplement reconciliation to screen for interacting drugs (MAOIs, bupropion, SNRIs, clonidine, stimulants)

Cadence: Check blood pressure and heart rate before starting and regularly during any use; reassess with a clinician if the product, dose, or symptoms change. There is no validated long-term monitoring schedule because chronic use is not evidence-supported.

Warning signs — seek care
  • Severe or throbbing headache, chest pain, palpitations, or very high blood pressure
  • Sudden neurologic symptoms: facial droop, one-sided weakness, slurred speech, vision change, seizure (possible stroke/hemorrhage)
  • Severe anxiety, panic attack, agitation, confusion, or loss of consciousness
  • Nausea, vomiting, profuse sweating, flushing, or tremor
  • Any of these warrant stopping the substance and seeking emergency care immediately
Do not use if

Contraindications

  • Hypertension or uncontrolled/labile blood pressure
  • Known cardiovascular disease, arrhythmia, or history of stroke/intracranial hemorrhage
  • Anxiety disorders, panic disorder, or PTSD (can provoke panic and worsen symptoms)
  • Concurrent use of drugs that raise noradrenergic tone or interact dangerously: MAO inhibitors, noradrenaline-reuptake-inhibiting antidepressants (e.g., bupropion, SNRIs such as desvenlafaxine), other stimulants
  • Concurrent or chronic clonidine/other alpha-2 agonist use (alpha-2 downregulation may potentiate yohimbine; implicated in an intracranial hemorrhage case)
  • Pregnancy and breastfeeding (no safety data; sympathomimetic)
  • Renal or hepatic impairment (altered handling/clearance; caution)
  • Combination with other sympathomimetic 'fat burner'/pre-workout stimulants
Combinations

Interaction profile

  • MajorWith an anabolic steroid: Additive cardiovascular strain
  • MajorWith a stimulant: Additive cardiovascular strain
  • ModerateWith a SARM: Additive cardiovascular strain
  • MajorWith thyroid hormone: Additive cardiovascular strain
  • ModerateWith a GLP-1 / incretin agonist: Additive cardiovascular strain
  • ModerateWith a melanocortin agonist: Additive hypertension
  • MajorWith a QT-prolonging drug: QT prolongation
  • ContraindicatedWith DNP: Additive cardiovascular strain

Check a specific combination in the interaction checker.

Harm reduction

Reducing harm & when to stop

  • Understand the evidence gap: controlled human trials do not show yohimbine improves fat loss, physique, or performance, so the physique-related risk-benefit is unfavorable.
  • The dose-response is unpredictable because individual oral bioavailability varies widely and supplement products are frequently mislabeled or adulterated, so a 'usual' dose can produce toxic blood levels in some people.
  • Screen medications first: avoid combining with MAOIs, noradrenaline-reuptake-inhibiting antidepressants (bupropion, SNRIs), clonidine/alpha-2 agonists, other stimulants, or stimulant 'fat burners'/pre-workouts.
  • Do not use with pre-existing hypertension, heart disease, arrhythmia, prior stroke/hemorrhage, anxiety/panic disorder, or PTSD.
  • Measure blood pressure and heart rate before and during any use; stop immediately for severe headache, chest pain, palpitations, marked BP rise, severe anxiety/panic, or any neurologic symptoms.
  • Seek emergency care for signs of stroke (facial droop, one-sided weakness, speech or vision change), seizure, loss of consciousness, or hypertensive-emergency symptoms. Yohimbine intoxication can be fatal.
  • Discuss any use, and any hormonal-recovery concerns from other agents, with a physician/endocrinologist rather than self-managing; this monograph is informational and not a recommendation to use.
Evidence

Citations (11)

Every clinical claim above is tied to a primary source. Overall evidence grade B — graded to the best available evidence for its core claims.

  1. 01

    Yohimbine is an alpha-2 adrenoceptor antagonist that blocks pre- and postsynaptic alpha-2 receptors, increasing noradrenaline (and dopamine) release; therapeutic 5-15 mg doses give ~40-400 ng/mL blood levels with neurotoxicity/fatality at higher concentrations.

    Case reportPMID 23846025 ↗

  2. 02

    Yohimbine is rapidly absorbed and rapidly eliminated with a mean plasma elimination half-life of ~0.6 h after 10 mg oral; renal excretion of unchanged drug is negligible (~0.35%) and it is cleared primarily by hepatic metabolism.

    CohortDOI 10.1007/BF02455991 ↗

  3. 03

    Single oral doses in healthy volunteers produce dose-related increases in AUC, blood pressure, respiratory rate, and plasma catecholamines/MHPG; oral bioavailability varies markedly between individuals and a high-fat meal reduces absorption.

    RCTDOI 10.1002/j.1552-4604.1996.tb04255.x ↗

  4. 04

    Meta-analysis of seven randomized placebo-controlled trials found yohimbine monotherapy superior to placebo for erectile dysfunction (OR ~3.85) with infrequent, reversible serious adverse reactions.

    Meta-analysisDOI 10.1016/s0022-5347(01)63942-9 ↗

  5. 05

    There is no conclusive evidence yohimbine benefits bodybuilding, exercise tolerance, physical performance, or body mass; excess doses typically cause agitation, anxiety, hypertension, and tachycardia (dose-dependent toxicity).

    ReviewDOI 10.3109/19390211.2011.615806 ↗

  6. 06

    In a 6-month randomized double-blind trial, high-dose oral yohimbine (peak 43 mg/day) had no effect on body weight, body fat, or fat distribution in men.

    RCTPMID 1960007 ↗

  7. 07

    A bodybuilder who ingested ~5 g yohimbine developed seizures, loss of consciousness, and hypertensive emergency (BP 259/107, HR 140), with an apparent overdose half-life of ~2 h.

    Case reportDOI 10.1080/15563650903081601 ↗

  8. 08

    A single labeled dose of a yohimbine-containing supplement was temporally associated with acute basal-ganglia and subarachnoid intracranial hemorrhage and hypertensive emergency in a patient on chronic clonidine plus bupropion and desvenlafaxine, illustrating dangerous drug interactions and supplement mislabeling.

    Case reportDOI 10.1016/j.ajem.2022.08.053 ↗

  9. 09

    Four simultaneous severe yohimbine poisonings (one fatal) presented with tachycardia, headache, nausea, vomiting, and sweating, with very high blood concentrations in the deceased.

    Case seriesDOI 10.1016/j.forsciint.2021.110705 ↗

  10. 10

    Intravenous yohimbine provoked panic attacks in 42% of PTSD patients and increased anxiety, panic, and PTSD symptoms, supporting its psychiatric (anxiogenic/panicogenic) risk.

    RCTDOI 10.1001/archpsyc.1997.01830200083012 ↗

  11. 11

    Topically applied yohimbine ointment did not produce significant thigh girth (fat) reduction in controlled trials, unlike other agents tested.

    RCTDOI 10.1002/j.1550-8528.1995.tb00228.x ↗

Last reviewed 2026-07-06 · Verified against PubMed · Educational, not medical advice