RAD-140 for muscle growth
Does RAD-140 build muscle in humans — and is "selective" doing the work people think it is?
The whole human record
RAD-140 — testolone, and under its international name vosilasarm — has been given to human beings in a clinical trial exactly once.
Every registered human trial of RAD-140
Twenty people, all of them postmenopausal women with breast cancer, in a dose-finding safety study that finished in 2020 and has never reported. Nothing about that trial speaks to whether a healthy 25-year-old gains muscle.
So the efficacy question has no human answer. That is not unusual on this shelf. What makes RAD-140 different is what fills the gap.
The only human data on people using it for muscle is harm
There is a body of published human evidence about RAD-140 taken by young men to build muscle. All of it consists of case reports of liver injury.
The most detailed is a 24-year-old man who took up to 15 mg daily for five weeks. He presented with two weeks of diffuse abdominal pain, yellowing of the eyes, itching, and jaundice.3
Peak laboratory values — Ochsner Journal case report
A liver biopsy showed intracytoplasmic and canalicular cholestasis with minimal portal inflammation — bile backing up inside liver cells — and no significant steatosis, necrosis or fibrosis.3 He recovered fully, roughly eighteen weeks after discharge.
For scale: NIH LiverTox describes the typical SARM liver-injury presentation as a bilirubin of 4.0 to 8.0 mg/dL.1 This case ran roughly five to nine times higher than that, after five weeks of use.
What the pattern looks like
NIH LiverTox, the National Institutes of Health reference for drug-induced liver injury, assigns SARMs a likelihood score of B — a likely cause of clinically apparent liver injury with jaundice. RAD-140 is named among the agents most frequently associated, alongside ligandrol, ostarine and andarine.1
SARM-associated liver injury, per LiverTox1
abdominal pain, itching
That last row matters and we want to state it plainly rather than bury it. LiverTox records that reported SARM liver injuries "have often been prolonged but have invariably resolved," and that transplantation was avoided.1 This is a different picture from ashwagandha, where the same database records rare fatal outcomes and emergency transplants.
The honest summary is: severe, slow to clear, and so far reversible on stopping. Not trivial, and not the worst thing on this site.
The proposed mechanism is worth noting because it leads somewhere. LiverTox suggests the injury is "likely to be the result of excessive androgen receptor engagement and resultant interference with hepatocellular transport mechanisms for export of bilirubin and bile acids."1
The word doing the most work is "selective"
The entire proposition of a SARM is in its name. Selective androgen receptor modulator — a compound that engages androgen receptors in muscle and bone while largely leaving other tissues alone. That selectivity is the reason they are marketed as a cleaner alternative to anabolic steroids.
Liver injury caused by excessive androgen receptor engagement is, on its face, a problem for that premise. The authors of the case report make the point directly:
The accumulating cases of drug-induced liver injury from SARMs raise concern about their hepatic safety and question the tissue selectivity of these agents. Leung et al., Ochsner Journal, 20223
This is the load-bearing claim of the whole category, and it is being tested by accident — in case reports, on people who volunteered themselves. Nobody has run the trial that would establish how selective RAD-140 actually is in humans, at the doses people take, over the durations they take them.
USADA's summary of the category lists reported effects including bone remodeling, testosterone suppression, and kidney, liver and prostate enlargement, and notes recent case reports of drug-induced liver injury, myocarditis and tendon rupture.4 That is a wide spread of tissues for a compound sold on not affecting them.
Two claims, two answers
Note the shape. The claim people act on has no human evidence at all; the claim nobody is told about has a national database entry and a stack of published cases. Our rubric reports safety rather than grading it, so the dots describe only the first row — which is exactly why the safety section on a page like this is not optional reading.
Safety and unknowns
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Adverse events reported
Clinically apparent cholestatic liver injury with jaundice, documented in multiple published case reports; NIH LiverTox likelihood score B.1 USADA additionally lists testosterone suppression, bone remodeling, kidney and prostate enlargement across the SARM class, plus case reports of myocarditis and tendon rupture.4
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Longest human exposure studied
Unknown in the population that uses it. The single registered trial ran in cancer patients and never posted results.2 Case reports describe injury after five weeks to several months of use — and LiverTox gives a latency range extending to a year,1 meaning short use is not a guarantee of having got away with it.
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Known interactions and at-risk groups
Not characterised. The reported cases are predominantly young men with no prior liver disease, which is the notable part — this is not injury concentrated in an already vulnerable group.
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Regulatory status
Not approved by the FDA for human use; all SARMs are investigational only.4 Not a controlled substance in the US — the SARMs Control Act has been introduced repeatedly since 2018 and has never passed. Prohibited by WADA at all times under S1.2, Other Anabolic Agents.4 FDA has issued warning letters to vendors marketing it as a supplement.
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What has not been characterized
Whether it builds muscle in humans at all. How often liver injury occurs — case reports establish that it happens, never the rate. Whether the injury is dose-dependent. What long-term androgen receptor engagement does to the tissues USADA lists. And, since it is sold as a research chemical, USADA notes a high risk of black-market products being contaminated with other substances,4 so a given vial may not contain what the label says.
How this was graded
Evidence strength — Preliminary, criteria checked
A completed trial that never reports is not evidence. It is a question that was asked, answered somewhere in a sponsor's files, and not shared — which leaves the public record exactly where it was before the trial ran.
Bottom line
RAD-140 has been formally tested in humans once — twenty postmenopausal women with breast cancer, in a trial that finished in 2020 and has never published a result. No study has ever measured whether it builds muscle in a healthy person.
What does exist in the human literature is a series of case reports of liver injury in young men who took it for exactly that purpose. One documented a bilirubin thirty-two times the upper limit of normal after five weeks of use, taking around eighteen weeks to resolve. The NIH classifies SARMs as a likely cause of clinically apparent liver injury with jaundice — though, importantly, the reported cases have so far resolved once people stopped.
The premise of the entire category is selectivity. The published human evidence for RAD-140 is a record of it acting somewhere it was not supposed to.
Sources
- National Institutes of Health, LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Selective Androgen Receptor Modulators. NCBI Bookshelf NBK619971
- ClinicalTrials.gov. NCT03088527 — Phase 1, First-in-Human Study of RAD140 in Postmenopausal Women With Breast Cancer. Sponsor: Stemline Therapeutics. Enrollment 20. October 2017 – September 2020. Results posted: no. clinicaltrials.gov
- Leung K, Yaramada P, Goyal P, et al. RAD-140 drug-induced liver injury. Ochsner Journal. 2022;22(4):361–365. PMC9753945
- US Anti-Doping Agency. Selective androgen receptor modulators (SARMs): prohibited class of anabolic agents. usada.org
Search results for this compound are dominated by vendor pages quoting an anabolic-to-androgenic ratio of 90:1. That figure comes from preclinical work, describes tissue response in animals, and is not a human finding. Under our sourcing standard none of those pages are usable as evidence for any mark, and none were used here.
