Supplements

Rauwolscine (Alpha-Yohimbine)

Updated · 22 sources

Rauwolscine, also sold as alpha-yohimbine (α-yohimbine), is a plant alkaloid and a stereoisomer of yohimbine: the same atoms in a different three-dimensional arrangement. Like yohimbine, it blocks alpha-2 adrenergic receptors, and it is sold in “fat burner” and pre-workout supplements as a stronger or “smoother” yohimbine alternative.

The single most important fact is that almost everything known about rauwolscine comes from laboratory and animal research, where it is a standard research tool for labeling alpha-2 receptors. We found no published clinical trial testing rauwolscine on its own in people for fat loss, performance or any other use, and Operation Supplement Safety, the US military’s supplement resource, states that no clinical studies on its safety or efficacy have been reported. It is not an approved drug anywhere we could find, and products that contain it are typically multi-stimulant blends with poor label accuracy.

This page summarizes what the pharmacology studies, supplement analyses and regulators report. It is for education only and is not medical advice.

Property Detail
Class Indole alkaloid (yohimban type); alpha-2 adrenergic receptor antagonist
Other names Alpha-yohimbine, α-yohimbine; a diastereoisomer of yohimbine and corynanthine
Formula C₂₁H₂₆N₂O₃, 354.4 g/mol (same as yohimbine)
Sources Rauvolfia species and yohimbe bark (Pausinystalia johimbe); can also be made in a laboratory
Route Oral (capsules, multi-ingredient powders)
Human dose data None from clinical trials; supplement labels commonly list a few milligrams (one recalled product listed 3 mg per capsule)
Half-life in humans Not established
US status No FDA-approved product; sold in dietary supplements without pre-market review; not on the DEA controlled-substance schedules
WADA status Not named on the 2026 Prohibited List

What it is

Rauwolscine is one of three closely related alkaloids, along with yohimbine and corynanthine, found in yohimbe bark (Cohen et al., Drug Test Anal 2016). All three share the formula C₂₁H₂₆N₂O₃ and differ only in the spatial arrangement of their atoms (PubChem: rauwolscine). Pharmacologists describe yohimbine, rauwolscine and corynanthine as diastereoisomers (Shepperson et al., J Pharmacol Exp Ther 1981).

Rauwolscine also occurs in Rauvolfia plants, which contain more than 30 chemical compounds, including rauwolscine and yohimbine (OPSS 2020). OPSS notes that rauwolscine can be extracted from plants or made in a laboratory, that it may appear on labels as “alpha-yohimbine” or “α-yohimbine,” and that a label listing only “rauwolscine” does not tell the buyer whether the ingredient is natural or synthetic.

The rationale for using it in supplements is borrowed from yohimbine HCl: blocking alpha-2 receptors removes a brake on norepinephrine release and on fat breakdown in fat cells. The yohimbine evidence itself is weak for fat loss, and none of it was generated with rauwolscine.

Mechanism

Rauwolscine’s main known action is alpha-2 adrenergic receptor blockade. It is so selective in binding studies that tritium-labeled rauwolscine became a standard laboratory tool for measuring these receptors:

  • In bovine brain tissue, [³H]rauwolscine bound alpha-2 receptors reversibly and with high affinity (dissociation constant about 2.5 nM), labeling both high- and low-affinity receptor states (Perry and U’Prichard, Eur J Pharmacol 1981).
  • Early tissue experiments described it as highly selective for presynaptic alpha-adrenoceptors, the receptors on nerve endings that limit norepinephrine release (Tanaka et al., Eur J Pharmacol 1978).

How selective it is in a living animal depends on the model:

Study Model Finding
Shepperson et al. 1981 Anesthetized dogs Rauwolscine and yohimbine were equipotent at alpha-2 receptors and about 30 times more potent there than at alpha-1 receptors
Doxey et al. 1984 Rat tissues and binding studies Alpha-2/alpha-1 selectivity ratios were 45 for yohimbine but only 3 for rauwolscine; rauwolscine was the most potent of the isomers at alpha-1 receptors

So the marketing claim that rauwolscine is a “cleaner” alpha-2 blocker than yohimbine is not supported consistently even in animal pharmacology.

Rauwolscine also acts on serotonin receptors:

These are cell and tissue findings. Whether these serotonin actions matter at supplement doses in people is unknown.

Pharmacokinetics

No human pharmacokinetic study of rauwolscine was found in PubMed or Europe PMC searches (November 2026). Its absorption, half-life, metabolism and the dose needed for receptor blockade in people have not been established. For comparison, its isomer yohimbine has a half-life under about 1.5 hours and an oral bioavailability that varied from 7% to 87% between individuals in one study (see the yohimbine HCl page). Those numbers cannot be assumed to apply to rauwolscine.

Regulatory status

  • No approved drug. A search of FDA’s Drugs@FDA data for rauwolscine as an active ingredient returned no matches (openFDA, accessed November 2026).
  • Sold as a supplement ingredient. The NIH Dietary Supplement Label Database returned 705 labels mentioning rauwolscine, including products no longer on the market (search in November 2026) (NIH DSLD). Dietary supplements do not need FDA approval before sale.
  • Not a controlled substance. Rauwolscine is not listed in the DEA schedules in 21 CFR 1308.
  • Military guidance. OPSS states that neither Rauvolfia nor rauwolscine is prohibited for US service members, but calls products listing rauwolscine and/or yohimbine “possibly unsafe” and warns that such products have been found to contain additional, sometimes hidden, stimulants (OPSS 2020).
  • European Union. Since 2019, yohimbe bark and its preparations have been prohibited in foods in the EU because no safety data were submitted (Regulation (EU) 2019/650). The regulation names the bark and its preparations; it does not mention isolated or synthetic rauwolscine.

What the research shows

In people: no rauwolscine-only trials

We did not find any published randomized trial that gave rauwolscine alone to people and measured fat loss, appetite, exercise performance, blood pressure or mood. OPSS reached the same conclusion: “No clinical studies on the safety or efficacy of rauwolscine have been reported” (OPSS 2020). Human data are limited to:

  • Laboratory studies on human tissue, such as receptor binding in human platelets and brain tissue (see Mechanism above).
  • Trials of multi-ingredient products. In a double-blind crossover study of 12 young adults, the original OxyELITE Pro formula raised blood markers of fat breakdown (glycerol and free fatty acids) and calorie expenditure over 2 hours, and also raised heart rate and systolic blood pressure compared with placebo (McCarthy et al., Nutr Metab Insights 2012). That product contained caffeine, 1,3-dimethylamylamine (DMAA) and several plant extracts in addition to “rauwolscine extract,” so the effects cannot be attributed to rauwolscine. FDA has since stated that DMAA is not a lawful dietary ingredient (FDA).

In animals

Study Finding
Callahan et al., Pharmacol Biochem Behav 1984 Yohimbine and rauwolscine reduced 3- and 6-hour food intake in food-restricted lean and genetically obese mice; obese mice were more sensitive
La Marca and Dunn, Life Sci 1994 Intravenous rauwolscine (2.24 mg/kg) had an anti-anxiety–like effect in a rat conflict test, whereas yohimbine did not; yohimbine is known to provoke anxiety in animals and people

The rat finding is sometimes cited online as evidence that rauwolscine causes less anxiety than yohimbine. It is a single intravenous animal experiment and has not been tested in people.

Side effects and risks

Because there are no human trials, there is no rauwolscine-specific adverse event profile. What can be said:

  • Expected alpha-2 blocker effects. Yohimbine, which shares rauwolscine’s main mechanism, is linked in poison-center data to rapid heart rate, high blood pressure and anxiety (see yohimbine HCl). A 2024 review of yohimbine noted that reported adverse events have occurred when it was taken in large quantities or combined with other stimulants such as caffeine, synephrine or rauwolscine (Porrill et al., Neurol Int 2024).
  • Stimulant stacking. In a 2023–2024 analysis of 44 weight-loss supplements bought on or near 12 US military bases, 89% listed caffeine in combination with other stimulants such as evodiamine, guarana, rauwolscine, yohimbe and yohimbine. Some listed more than 200 mg of caffeine per serving, and 64% used proprietary blends that hid individual amounts (Crawford et al., Nutrients 2024).
  • Cardiovascular and psychiatric caution. By analogy with yohimbine, people with high blood pressure, heart rhythm problems, panic or anxiety disorders, or who take MAOIs, tricyclic antidepressants or clonidine, are the groups for whom an alpha-2 blocker is most likely to cause harm. This is an inference from yohimbine data, not a rauwolscine study.
  • Pregnancy and breastfeeding. No data.

Quality and labeling

The supplement analyses that exist point the same way:

  • Weight-loss supplements near military bases. Of 44 products, 82% had inaccurate labels, 61% listed ingredients that were not detected, 36% contained hidden ingredients, and 91% scored “no-go” on the OPSS risk scorecard. None carried a third-party certification seal (Crawford et al., Nutrients 2024).
  • Online weight-loss products with military discounts. Of 30 products, 25 had inaccurate labels, 7 contained hidden components, and 10 listed or contained substances on the Department of Defense prohibited list (Crawford et al., JAMA Netw Open 2024).
  • Yohimbe and yohimbine products. Among 49 US brands, 39% contained no rauwolscine or corynanthine at all, suggesting their yohimbine was synthetic or highly processed rather than whole bark (Cohen et al., Drug Test Anal 2016). The presence or absence of rauwolscine in a “yohimbe” product therefore says something about how it was made.
  • Recall. In September 2024 a 3 mg rauwolscine capsule product (Gorilla Mind Rauwolscine, 90 capsules) was recalled in a Class I recall, FDA’s most serious category, for potential Salmonella contamination (openFDA food enforcement record F-0053-2025). The recall concerned contamination, not rauwolscine itself.

Rauwolscine is not named on the WADA 2026 Prohibited List, and neither is yohimbine (WADA 2026 Prohibited List). The S6 stimulant section does, however, include “other substances with a similar chemical structure or similar biological effect(s),” and WADA has not published guidance on how that wording applies to rauwolscine. The more practical risk for tested athletes is that products listing rauwolscine are often multi-stimulant blends, and the label studies above found hidden and prohibited ingredients.

Key takeaways

  • Yohimbine’s stereoisomer. Rauwolscine (alpha-yohimbine) has the same formula as yohimbine and also blocks alpha-2 adrenergic receptors; it additionally acts on 5-HT1A and 5-HT2B serotonin receptors in cell studies.
  • No human trials. We found no published clinical trial of rauwolscine alone, and its human dose, half-life and safety profile are not established.
  • Selectivity claims are shaky. One animal study found it as alpha-2 selective as yohimbine; another found it far less selective.
  • The only human data come from blends. A small trial of OxyELITE Pro, which also contained DMAA and caffeine, raised fat-breakdown markers along with heart rate and blood pressure.
  • Labels are unreliable. Weight-loss supplements that list rauwolscine are usually stimulant stacks, and most tested products had inaccurate labels or hidden ingredients.
  • Not approved, not scheduled, not named by WADA. It is sold in hundreds of US supplements without FDA review of safety or efficacy.

Sources

  1. National Center for Biotechnology Information. Rauwolscine (CID 643606). PubChem. PubChem.
  2. Cohen PA, Wang YH, Maller G, DeSouza R, Khan IA. Pharmaceutical quantities of yohimbine found in dietary supplements in the USA. Drug Test Anal. 2016;8(3-4):357–369. PubMed.
  3. Shepperson NB, Duval N, Massingham R, Langer SZ. Pre- and postsynaptic alpha adrenoceptor selectivity studies with yohimbine and its two diastereoisomers rauwolscine and corynanthine in the anesthetized dog. J Pharmacol Exp Ther. 1981;219(2):540–546. PubMed.
  4. Operation Supplement Safety (Uniformed Services University, CHAMP). Rauwolscine and Rauwolfia: read your label carefully. Updated November 3, 2020. OPSS.
  5. Perry BD, U’Prichard DC. [3H]rauwolscine (alpha-yohimbine): a specific antagonist radioligand for brain alpha 2-adrenergic receptors. Eur J Pharmacol. 1981;76(4):461–464. PubMed.
  6. Tanaka T, Weitzell R, Starke K. High selectivity of rauwolscine for presynaptic alpha-adrenoceptors. Eur J Pharmacol. 1978;52(2):239–240. PubMed.
  7. Doxey JC, Lane AC, Roach AG, Virdee NK. Comparison of the alpha-adrenoceptor antagonist profiles of idazoxan (RX 781094), yohimbine, rauwolscine and corynanthine. Naunyn Schmiedebergs Arch Pharmacol. 1984;325(2):136–144. PubMed.
  8. Arthur JM, Casañas SJ, Raymond JR. Partial agonist properties of rauwolscine and yohimbine for the inhibition of adenylyl cyclase by recombinant human 5-HT1A receptors. Biochem Pharmacol. 1993;45(11):2337–2341. PubMed.
  9. Wainscott DB, Sasso DA, Kursar JD, Baez M, Lucaites VL, Nelson DL. [3H]Rauwolscine: an antagonist radioligand for the cloned human 5-hydroxytryptamine2b (5-HT2B) receptor. Naunyn Schmiedebergs Arch Pharmacol. 1998;357(1):17–24. PubMed.
  10. US Food and Drug Administration. openFDA Drugs@FDA dataset: search for active ingredient rauwolscine (no matching records; accessed November 2026). openFDA.
  11. National Institutes of Health, Office of Dietary Supplements. Dietary Supplement Label Database: search for “rauwolscine” (accessed November 2026). NIH DSLD.
  12. Drug Enforcement Administration. Schedules of controlled substances. 21 CFR part 1308. eCFR.
  13. European Commission. Commission Regulation (EU) 2019/650 of 24 April 2019 amending Annex III to Regulation (EC) No 1925/2006 as regards Yohimbe (Pausinystalia yohimbe (K. Schum) Pierre ex Beille). 2019. EUR-Lex.
  14. McCarthy CG, Farney TM, Canale RE, Alleman RJ, Bloomer RJ. A finished dietary supplement stimulates lipolysis and metabolic rate in young men and women. Nutr Metab Insights. 2012;5:23–31. PubMed.
  15. US Food and Drug Administration. DMAA in products marketed as dietary supplements. FDA.
  16. Callahan MF, Beales M, Oltmans GA. Yohimbine and rauwolscine reduce food intake of genetically obese (obob) and lean mice. Pharmacol Biochem Behav. 1984;20(4):591–599. PubMed.
  17. La Marca S, Dunn RW. The alpha-2 antagonists idazoxan and rauwolscine but not yohimbine or piperoxan are anxiolytic in the Vogel lick-shock conflict paradigm following intravenous administration. Life Sci. 1994;54(10):PL179–184. PubMed.
  18. Porrill SL, Rogers RR, Ballmann CG. Ergogenic and sympathomimetic effects of yohimbine: a review. Neurol Int. 2024;16(6):1837–1848. PubMed.
  19. Crawford C, Lindsey AT, Avula B, Katragunta K, Khan IA, Deuster PA. Label accuracy and quality of select weight-loss dietary supplements sold on or near US military bases. Nutrients. 2024;16(24):4369. PubMed.
  20. Crawford C, Avula B, Lindsey AT, Katragunta K, Khan IA, Deuster PA. Label accuracy of weight loss dietary supplements marketed online with military discounts. JAMA Netw Open. 2024;7(5):e249131. PubMed.
  21. US Food and Drug Administration. openFDA food enforcement report F-0053-2025: Gorilla Mind Rauwolscine dietary supplement, Class I recall initiated September 6, 2024 (accessed November 2026). openFDA.
  22. World Anti-Doping Agency. The 2026 Prohibited List. In force January 1, 2026. WADA.