RAD-140

Overview

RAD-140 (testolone) is a non-steroidal small-molecule selective androgen receptor modulator (SARM) — not a peptide — developed by Radius Health. It is NOT FDA-approved for any indication. Grey-market use for bodybuilding is associated with documented drug-induced liver injury (hepatotoxicity), testosterone suppression, and adverse cardiovascular effects. It is a WADA-prohibited substance. It is tracked in peptide-research spaces because of overlapping grey-market performance use.

Mechanism of Action

RAD-140 binds the androgen receptor with high affinity and acts as a tissue-selective AR agonist — anabolic in skeletal muscle and bone with relatively reduced androgenic activity in prostate and sebaceous glands in preclinical models. Selectivity is dose-dependent and modest, and RAD-140 still suppresses the HPG axis via negative feedback, reducing endogenous testosterone. It does not aromatize to estrogen.

Research Summary

Preclinical studies (Miller et al. 2010; Jayaraman et al. 2014) characterized RAD-140's anabolic and neuroprotective effects. A first-in-human Phase 1 dose-escalation study in ER+/HER2- metastatic breast cancer (LoRusso et al. 2022) showed preliminary activity at 100 mg/day but frequent hepatic AEs (elevated AST 59%, ALT 46%, bilirubin 27%); development in oncology was not advanced. Clinical development in cachexia has not produced an approval. Multiple published case reports document severe cholestatic drug-induced liver injury from grey-market RAD-140 use. FDA has repeatedly warned that SARMs including RAD-140 are not safe for human consumption, and the compound is banned by WADA.

Dosing Information

Reported Side Effects

• Drug-induced liver injury / hepatotoxicity (multiple published case reports, including cholestatic hepatitis with markedly elevated bilirubin)
• Testosterone / HPG axis suppression (dose-dependent, commonly requires PCT in grey-market use)
• HDL cholesterol suppression and potential cardiovascular risk
• Elevated AST/ALT and total bilirubin
• Hair shedding
• Headache
• Aggression or mood changes
• Acne

Research References

• Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140 (Miller et al., ACS Med Chem Lett) (2010)
• Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats (Jayaraman et al., Endocrinology) (2014)
• A First-in-Human Phase 1 Study of a Novel Selective Androgen Receptor Modulator (SARM), RAD140, in ER+/HER2- Metastatic Breast Cancer (LoRusso et al., Clinical Breast Cancer) (2022)
• RAD-140 Drug-Induced Liver Injury (Leung et al., Ochsner Journal) — cholestatic hepatitis case report (2022)
• Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet (Van Wagoner et al., JAMA) (2017)