History

RAD140 was discovered by Radius Health and first characterized in the peer-reviewed literature by Miller et al. (2011), who described its androgen-receptor binding and tissue-selective anabolic activity in rodent and primate models. Radius later pursued RAD140 as an oral agent for androgen-receptor-positive, estrogen-receptor-positive breast cancer (rationale from Yu et al., 2017), advancing it into a Phase 1 oncology trial (NCT03088527). Public reporting indicates that program was discontinued; precise final outcome details are not confirmed here and are omitted.

Testolone (RAD-140) is a selective androgen receptor modulator (SARM) — a non-steroidal small molecule, not a peptide and not an anabolic steroid. It was developed as an investigational drug, never approved for any use, and is widely sold online for muscle building despite the complete absence of published human efficacy data for that purpose. What human evidence exists comes only from an oncology setting, and the compound carries real documented harms.

What it is

RAD-140 binds the androgen receptor (AR) as an agonist with tissue selectivity, designed in preclinical work to favor anabolic effects on muscle and bone while exerting weaker androgenic activity on tissues such as the prostate than testosterone does. How well that selectivity holds in humans is not well characterized. It was discovered by Radius Health and is referred to in the literature by the development code RAD140. Notably, Radius investigated RAD140 not for muscle building but as an oral AR-targeting agent for AR-positive, ER-positive breast cancer.

The claims

In fitness, bodybuilding, and biohacking circles, RAD-140 is marketed and used as an oral “muscle-building” or “lean mass / strength” agent, often promoted as a lower-side-effect alternative to anabolic steroids or testosterone. It is sold as a “research chemical,” labeled “not for human consumption,” or disguised in products presented as dietary supplements. The claims of large muscle gains with minimal androgenic side effects are marketing claims: there are no published controlled human efficacy trials in healthy people supporting body-composition or performance benefits.

What the evidence actually shows

The foundational pharmacology (Miller et al., 2011) describes RAD140’s discovery, AR binding, and tissue-selective anabolic activity in rodents, with activity in a primate model. This is animal and in-vitro data, not human efficacy. Yu et al. (2017) reported RAD140 activity in AR+/ER+ breast cancer models with a distinct mechanism of action, providing the rationale for the clinical program. The only human exposure is in oncology (Phase 1, NCT03088527); a first-in-human Phase 1 report in ER+/HER2− metastatic breast cancer exists, but no fitness or body-composition efficacy data in healthy people are published. In short, human efficacy evidence for the fitness uses is absent, and the body-composition rationale rests on preclinical data only.

Legal and regulatory status

The U.S. FDA states that SARMs, including RAD-140, are not lawful dietary-supplement ingredients and are not FDA-approved for any use. The FDA has warned consumers and companies about SARMs, citing risks including liver injury and increased risk of heart attack and stroke, and has issued warning letters to companies marketing SARMs in supplement-style products. RAD-140 and most SARMs are not currently scheduled as DEA controlled substances. A “SARMs Control Act” has been introduced in Congress in multiple sessions to schedule SARMs, but its enactment into law is not confirmed as of June 2026 — it should be treated as proposed, not enacted. SARMs are distinct from anabolic-androgenic steroids such as oxandrolone (a Schedule III controlled substance under the Anabolic Steroid Control Act), which is part of why separate SARMs-specific legislation has been proposed.

In sport, SARMs including RAD140/Testolone are prohibited at all times (in- and out-of-competition) under the WADA Prohibited List, Section S1 Anabolic Agents — specifically S1.2, “Other Anabolic Agents,” where SARMs are explicitly listed (RAD140 is named alongside andarine, ostarine, LGD-4033, S-23, and YK-11). RAD-140 is a recurrent cause of athlete adverse analytical findings and is detectable in anti-doping testing.

Safety

Drug-induced liver injury (documented in humans): A published case report describes cholestatic liver injury attributed to RAD-140 taken in bodybuilding supplements (Barbara, Dhingra & Mindikoglu, 2020), involving the products “Alpha Bolic” (RAD-140) and “Alpha Elite” (RAD-140 and LGD-4033). SARM-associated hepatotoxicity, including from RAD-140, is also covered in NIH LiverTox and additional published case reports.
Testosterone/HPG-axis suppression: As an AR agonist, RAD-140 is expected to suppress endogenous testosterone and gonadotropins (LH/FSH); suppression is a recognized SARM class effect. Human quantitative data specific to RAD-140 are limited.
Lipids: SARMs as a class are associated with reductions in HDL cholesterol, best documented for ostarine (enobosarm). RAD-140-specific human lipid data are limited.
Product-quality risk: Independent analysis of products sold as SARMs (Van Wagoner et al., JAMA 2017) found that many were mislabeled, underdosed, contained unapproved drugs, or contained none of the claimed compound — a real-world hazard for anyone buying these products.

A note on misattributed harms: some effects commonly cited online belong to other compounds, not RAD-140. Vision disturbances (yellow-tinged vision, poor night vision) are reported with andarine (S-4), a different SARM. Multi-organ carcinogenicity in long-term rodent studies belongs to GW-501516 (cardarine), which is a PPARδ agonist, not a SARM. These should not be attributed to RAD-140.

Bottom line

RAD-140 is an investigational, non-approved SARM with no human efficacy evidence for fitness uses, a class-typical hormone-suppression profile, at least one documented serious human liver-injury case, frequent product mislabeling, and prohibited status in sport. The strongest data are preclinical (animal and in-vitro). Marketing claims of safe, effective muscle gain are not supported by published human trials.

Evidence grade: Animal only.