Rauwolfia (Alpha-Yohimbine standardised extract)
Rauwolfia extracts standardised for alpha-yohimbine (rauwolscine) are used in fat-burners as an alpha-2 adrenergic antagonist to promote fat mobilisation and energy. Human evidence for the standardised supplement is thin, and it carries anxiety and blood-pressure risks similar to yohimbine.
01 Overview
Rauwolfia vomitoria and related species contain multiple alkaloids; supplements often standardise for alpha-yohimbine (rauwolscine), a stereoisomer of yohimbine, and sometimes crude rauwolfia. It is marketed as a stronger, longer-acting alternative to yohimbine for stubborn-fat loss.
Because alkaloid content in botanical extracts varies, dosing is inconsistent, and the same adrenergic side effects seen with yohimbine apply. This entry covers the standardised botanical product; the isolated isomer rauwolscine is catalogued separately.
02 Mechanism
Alpha-2 adrenergic receptor antagonist; blocking presynaptic alpha-2 autoreceptors increases noradrenaline release and reduces the fat-cell brake on lipolysis.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common | 1–3 mg | Oral | Standardised alpha-yohimbine content; start low. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Enhanced fat mobilisationAlpha-2 blockade can raise lipolysis, especially in fasted state. | Modest | Preclinical | |
| Stimulation and energyIncreased noradrenaline drives alertness. | Moderate | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Anxiety and panicAlpha-2 antagonism reliably provokes anxiety and can trigger panic attacks. | Moderate | Common | Observational | |
| Elevated blood pressure and heart rateNoradrenergic activation raises blood pressure and heart rate. | Moderate | Common | Observational |