RAD-140 (Testolone) — Evidence Review

What it is

RAD-140 (Testolone) is a synthetic, orally active nonsteroidal selective androgen receptor modulator discovered by Radius Health and characterised preclinically around 2011. It was designed to activate the androgen receptor in muscle and bone with less activity in the prostate than testosterone. Its only legitimate development pathway has been in oncology: an early breast-cancer program, where it received the international nonproprietary name "vosilasarm" and, after reformulation for improved pharmacokinetics, is being developed by Ellipses Pharmaceuticals as EP0062. It has never been approved for any use. Outside of trials it is sold illicitly online as a "research chemical" / bodybuilding supplement, which is where nearly all of its documented human harm — principally liver injury — has occurred.

How it works

RAD-140 is a small nonsteroidal molecule that binds the androgen receptor (AR) with high affinity — reported Ki ~7 nM, comparable to dihydrotestosterone (~10 nM) and tighter than testosterone (~29 nM) — and with selectivity over other steroid nuclear receptors. Ligand binding drives AR conformational change, nuclear translocation and tissue-selective coactivator recruitment, producing agonist (anabolic) signalling in skeletal muscle and bone while, in animal models, sparing prostate tissue relative to testosterone (levator-ani-favouring anabolic:androgenic selectivity). In AR+/ER+ breast cancer cells it acts as an AR agonist that represses ESR1 (estrogen receptor) transcription — a distinct mechanism from prostate tissue and the rationale for its oncology program.

Efficacy — what the human evidence shows

The Institute grades each claimed effect by the strength of the human evidence behind it. Grades are assigned independently for benefit and for harm.

Muscle mass / anabolic effect (the use for which it is actually bought)Insufficient

No human trial has ever tested RAD-140 for muscle growth or strength. Anabolic activity is documented only in animals.

Preclinical only: Miller et al 2011 (ACS Med Chem Lett) reported AR Ki ~7 nM and levator-ani muscle growth in rats from 0.1 mg/kg, with good oral bioavailability in rats and monkeys; Puskas et al 2025 (Physiol Rep) reports rodent muscle/bone effects. No human muscle or strength endpoint has been published.

Antitumor activity in AR+/ER+/HER2- metastatic breast cancerPreliminary

A single-arm first-in-human phase 1 showed on-target AR engagement but only modest clinical benefit; a reformulated version (vosilasarm/EP0062) is in ongoing phase 1/2 trials.

LoRusso et al, Clin Breast Cancer 2022 — phase 1 dose-escalation, n=22 heavily-pretreated postmenopausal women, MTD 100 mg/day; 1 partial response (in an ESR1-mutant patient), clinical benefit rate 18.2% at 24 weeks, median PFS 2.3 months. Human but early-phase, non-randomised, small. Follow-on NCT05573126 (vosilasarm) ongoing; ASCO 2025 phase 1 data reported.

Bone mineral densityInsufficient

Increased bone density shown only in preclinical models; no human bone data.

Rodent/preclinical models (Miller et al 2011; Puskas et al 2025). No human BMD trial.

Safety signals

Harm signals are reported prominently even where the evidence grade is low. Absence of evidence is not evidence of safety.

Drug-induced liver injury (cholestatic and hepatocellular)Probable

This is the dominant, best-documented harm. In the phase 1 breast-cancer trial, liver enzyme elevations were common: AST elevated in 59%, ALT in 46% and bilirubin in 27% of 22 patients, and grade 3/4 adverse events (mainly AST/ALT elevation) occurred in 72.7%. Separately, multiple peer-reviewed case reports describe SEVERE clinically-apparent liver injury in otherwise healthy young men using RAD-140 for muscle: e.g. a 26-year-old with hepatocellular injury (ALT 243, bilirubin 4.9 mg/dL) after ~2 months (Ladna 2023); a 43-year-old with profound cholestatic jaundice (bilirubin 708 micromol/L, ~41 mg/dL, INR 1.5) after 2 months (Perananthan & George 2024); and a case with peak bilirubin ~41.5 mg/dL. Injury typically appears after weeks to a few months and resolves over months after stopping, but has been life-threatening. LiverTox rates SARMs likelihood 'B' (a likely cause of clinically apparent liver injury). Absence of long-term safety data is not evidence of safety.

Androgen-receptor activation and HPG-axis / endocrine suppressionProbable

In the phase 1 trial, SHBG fell in 18/18 patients and PSA rose in 16/20, confirming systemic androgen-receptor activation. Suppression of endogenous testosterone is the expected on-target consequence, consistent with the androgen/anabolic-steroid class, although dedicated human endocrine-recovery data for RAD-140 are limited.

Cardiovascular and lipid effectsInsufficient

FDA warns that SARM bodybuilding products carry increased risk of heart attack and stroke, and androgenic compounds characteristically suppress HDL cholesterol; however, RAD-140-specific cardiovascular or lipid outcome data are essentially absent. Reported but unquantified for this compound.

Product adulteration / mislabelingPreliminary

Products sold as 'RAD-140' are frequently mislabeled, underdosed or contaminated; case-report authors explicitly could not exclude contaminants as contributors to the observed liver injury given the unregulated supply. FDA has issued warning letters to distributors.

Human trials on record

Study / registry	Phase	Population	Key result
LoRusso et al 2022, Clinical Breast Cancer 22(1):67-77 (Radius Health first-in-human, RAD140)	Phase 1 (dose-escalation, 3+3, single-arm)	22 heavily-pretreated postmenopausal women with AR+/ER+/HER2- metastatic breast cancer (dose levels 50/100/150 mg/day)	MTD 100 mg/day; grade 3/4 treatment-emergent AEs in 72.7% (mainly AST/ALT elevation and hypophosphatemia). Target engagement confirmed (SHBG down in 18/18, PSA up in 16/20). 1 partial response (ESR1-mutant); clinical benefit rate 18.2% at 24 weeks; median PFS 2.3 months.
NCT05573126 — Vosilasarm (EP0062), Ellipses Pharmaceuticals; ASCO 2025 phase 1 readout (JCO 2025 abstract 1057)	Phase 1/2 (ongoing as of 2025-2026)	Advanced/metastatic AR+/ER+/HER2- breast cancer; monotherapy and combinations (e.g. with CDK4/6 inhibitors)	EP0062 is a reformulation of RAD-140 with improved bioavailability/PK. Phase 1 (module A) dose-finding completed and an optimal dose selected for phase 2 (module B) expansion; safety/efficacy data still maturing.

Legal & regulatory status

United States

Not FDA-approved for any indication. FDA classifies SARM bodybuilding products as unapproved drugs (not lawful dietary supplements) and has publicly warned they are linked to serious liver injury, and increased risk of heart attack and stroke; it has issued warning letters to sellers. Legitimate use is investigational only, as vosilasarm/EP0062 in breast-cancer trials.

Anti-doping (WADA)

Prohibited at all times (in- and out-of-competition) under Section S1.2 'Other Anabolic Agents' as a SARM on the WADA Prohibited List; RAD-140 is among the most frequently detected SARMs in anti-doping testing.

Other jurisdictions

Marketed and sold as a 'research chemical' worldwide despite lacking approval; products are frequently mislabeled or contaminated.

The bottom line

RAD-140 is a real, potent nonsteroidal SARM, not a mislabeled peptide or PPAR agonist. But its reputation as a "safe" testosterone alternative is not supported: the only controlled human data come from a small phase 1 breast-cancer trial in which liver enzyme elevations were extremely common (AST 59%, ALT 46%, bilirubin 27% of 22 patients), and the published real-world experience is a series of severe, sometimes near-fatal cholestatic and hepatocellular liver injuries in young men who took it for muscle. There is NO human evidence that it builds muscle, and it is banned in sport (WADA S1.2) and unapproved by FDA. The honest summary: unproven benefit for bodybuilding, a well-documented signal of serious idiosyncratic liver injury, and an unregulated, frequently-contaminated supply.

References

Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140ACS Medicinal Chemistry Letters, 2011 (PMID 24900290)
Selective Androgen Receptor Modulator RAD140 Inhibits the Growth of Androgen/Estrogen Receptor-Positive Breast Cancer Models with a Distinct Mechanism of ActionClinical Cancer Research, 2017;23(24):7608-7620
A First-in-Human Phase 1 Study of a Novel Selective Androgen Receptor Modulator (SARM), RAD140, in ER+/HER2- Metastatic Breast CancerClinical Breast Cancer, 2022;22(1):67-77 (LoRusso et al)
Selective Androgen Receptor Modulators (LiverTox: Clinical and Research Information on Drug-Induced Liver Injury)NCBI Bookshelf / NIDDK, NBK619971
Idiosyncratic drug-induced liver injury related to use of novel selective androgen receptor modulator RAD140 (Testolone): a case reportJournal of Medical Case Reports, 2023 (PMID 36978171)
Severe liver injury following use of RAD-140, a selective androgen receptor modulator, for body buildingAustralian Prescriber, 2024 (PMID 38444893)
The Prohibited List (S1.2 Other Anabolic Agents — SARMs)World Anti-Doping Agency (WADA)
Certain Bodybuilding Products Put Consumers at Risk for Heart Attack, Stroke, Serious Liver Damage and MoreU.S. Food and Drug Administration (FDA)
Results of a phase 1 study of vosilasarm (EP0062), a first-in-class oral SARM, in patients with advanced or metastatic AR+/ER+/HER-2- breast cancerJournal of Clinical Oncology, 2025;43(16_suppl):1057 (ASCO abstract)
Phase 1/2 Study to Evaluate Vosilasarm (EP0062) as Monotherapy and in Combination in Patients With Advanced or Metastatic AR+/HER-2-/ER+ Breast CancerClinicalTrials.gov, NCT05573126 (Ellipses Pharmaceuticals)

SARMS Institute Research Desk. Compiled from primary sources. Last updated 20 July 2026.
This review is for education and does not provide medical or legal advice. No SARM is approved for human use.