Octopamine
Octopamine is a trace amine and adrenergic-related compound sold as a fat-burner supplement ingredient, often derived from bitter orange (Citrus aurantium) alongside synephrine. It is claimed to promote lipolysis via beta-3 adrenergic-like activity, but human evidence is minimal and largely anecdotal, and oral bioavailability is poor. Its main documented risk is additive cardiovascular stimulation when stacked with other stimulants.
01 Overview
Octopamine is a naturally occurring trace amine structurally related to noradrenaline, found in small amounts in citrus and acting as a neurotransmitter in invertebrates. In supplements it is marketed as a lipolytic 'fat burner', with the rationale that it stimulates beta-3 adrenergic-like receptors on fat cells to promote fat breakdown.
Human data are thin: most support comes from in-vitro and animal work, and octopamine is poorly absorbed orally and rapidly metabolised by monoamine oxidase, which limits any systemic effect from oral doses. Its practical relevance is as a minor component of bitter-orange fat-burner stacks, where the main concern is additive cardiovascular and sympathomimetic effects when combined with synephrine, caffeine and other stimulants. It is also a WADA-prohibited substance in sport.
02 Mechanism
Trace amine with weak adrenergic activity, proposed to stimulate beta-3 (and possibly beta-2) adrenergic-like receptors on adipocytes to promote lipolysis. Poor oral bioavailability and rapid MAO metabolism limit systemic effect.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Supplement dose | 20–100 mg/day | Oral | Typical fat-burner supplement range; effect on humans is poorly established and oral bioavailability is low. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Claimed lipolysisPromotes fat-cell lipolysis in vitro and in animal models; human effect from oral dosing is unproven. | unproven in humans | Preclinical | |
| Mild stimulant effectAnecdotal mild stimulant/energising effect within stacks, hard to separate from co-ingredients. | minor | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Cardiovascular stimulation (in stacks)Additive raised heart rate and blood pressure when combined with synephrine, caffeine and other stimulants in fat-burner products. | Moderate | Context-dependent | Anecdotal | |
| Anxiety and jitterinessReported jitteriness or anxiety, mainly in stimulant combinations. | Mild | Sparse data | Anecdotal |