RAD-140

RAD-140 (RAD140), also called testolone and vosilasarm, is a nonsteroidal selective androgen receptor modulator, or SARM. Radius Health chemists described it in 2011 as a potent, orally bioavailable SARM (Miller et al., 2011). Its only clinical trial in PubMed is a phase 1 study in women with metastatic breast cancer (LoRusso et al., 2022).

Published work on RAD-140 falls into six areas, each summarized with its model. Beyond one phase 1 trial, excretion studies and case reports, the data come from cells and animals.

Discovery and androgen receptor selectivity

RAD-140 bound the androgen receptor with a Ki of 7 nM (testosterone 29 nM, DHT 10 nM). In castrated immature rats, it raised levator ani muscle weight from 0.03 mg/kg by mouth but never matched testosterone propionate on the prostate or seminal vesicles, and at 10 mg/kg it partly blocked testosterone's effect on the seminal vesicles.

In young intact rats, prostate weight rose only at 30 mg/kg, the highest level tested (Miller et al., 2011). An independent group found androgenic activity in yeast and prostate cancer cell assays, consistent with docking to the receptor (Zierau et al., 2019). Models: receptor assays, cells and rats.

Monkey and mouse studies

In young male cynomolgus monkeys over 28 days, mean body weight, the authors' marker of anabolic action, rose more than 10 percent at 0.1 mg/kg by mouth, with no significant DEXA change in lean or fat tissue; LDL, HDL and triglycerides fell, and transaminases stayed within twofold of baseline (Miller et al., 2011).

In female mice, 10 weeks at 5 mg/kg raised frailty status and mortality risk (Brown et al., 2023). In mice about two years old, six weeks at 5 mg/kg a day left frailty unchanged, with lean mass and bone mineral density preserved in males only (Heinze et al., 2025). Models: monkeys and mice (animal data only).

Neuroprotection in rat neurons and rats

In cultured rat hippocampal neurons, RAD-140 was as effective as testosterone at reducing cell death from apoptotic insults. It raised ERK phosphorylation, and the MAPK kinase inhibitor U0126 blocked the protection. In gonadectomized adult male rats, it largely spared the prostate, activated androgen-regulated genes in the brain and protected hippocampal neurons against the excitotoxin kainate (Jayaraman et al., 2014). Two of the seven authors were from Radius Health, and no independent replication is indexed in PubMed. Models: rat neuron cultures and rats (cell and animal data only).

Breast cancer models and the first human trial

Radius Health scientists reported that RAD-140 activated the androgen receptor in breast cancer but not prostate cancer cells and substantially inhibited the growth of AR/ER-positive patient-derived xenografts in mice, more so with palbociclib (Yu et al., 2017). An independent group found it slowed only androgen receptor-high breast cancer models (Wei et al., 2023). In the first-in-human phase 1 study, 22 postmenopausal women with ER+/HER2- metastatic breast cancer received one of three daily amounts.

The most frequent adverse events were raised AST (59 percent), ALT (46 percent) and bilirubin (27 percent), vomiting, dehydration and decreased appetite and weight; 73 percent had grade 3 or 4 events. One woman had a partial response, and median progression-free survival was 2.3 months (LoRusso et al., 2022). No later RAD-140 trial report is indexed in PubMed. Models: cells, mouse xenografts and one human trial.

Liver and heart case reports

A 24-year-old man developed biopsy-supported cholestatic liver injury after five weeks of a product sold as RAD-140 and recovered after stopping (Leung et al., 2022). A 52-year-old man had similar injury after two supplements containing RAD-140, one also with LGD-4033 (Barbara et al., 2020).

A 2026 case its authors call the most severe so far followed a product with RAD-140 and andarine and needed plasmapheresis and intensive care (Dao et al., 2026). A 32-year-old man developed suspected acute myocarditis without coronary blockage (Padappayil et al., 2022), and a 16-year-old boy had myopericarditis on cardiac MRI hours after first use (Schwartzman et al., 2024). Case reports show an association, not proof of cause. Models: human case reports.

Metabolism and doping control

Excretion studies in male volunteers given microgram amounts found metabolites not reported before in human urine; the parent compound stayed detectable longest, up to 29 days after a single intake (Wagener et al., 2022). Models: reference material and human urine.