RAD-140 (Testolone)

RAD-140 (Testolone, also being developed as "Vosilasarm") is an oral SARM with real first-in-human trial data — though that data comes from a cancer-patient population, not healthy volunteers.

First-in-human Phase 1 trial (n=22 postmenopausal women with metastatic ER+/HER2- breast cancer, 21 AR-positive): doses of 50, 100 (maximum tolerated dose), and 150mg daily tested. One partial response occurred at the 100mg dose in a patient with a specific tumor mutation; overall clinical benefit rate at 24 weeks was 18.2%, median progression-free survival 2.3 months. LoRusso et al., Clin Breast Cancer, 2022 This trial was designed to test RAD-140 as a targeted cancer therapy, not as a muscle-building compound — the population and purpose are different from typical research-use context.

The Phase 1 trial tested 50mg, 100mg, and 150mg daily, oral, with 100mg identified as the maximum tolerated dose in that specific (cancer-patient) population — this isn't necessarily the same as a safe dose in a healthy-user context, which wasn't studied.

This is a real, significant safety signal worth leading with, not minimizing. The most frequent adverse events were elevated liver enzymes — AST elevated in 59.1% of patients, ALT in 45.5%, and total bilirubin in 27.3% — with Grade 3/4 liver enzyme elevations in roughly 23% of patients. Treatment-related side effects of any kind occurred in 77.3% of participants. SHBG decreased in nearly all patients and PSA increased in most, confirming the drug was actively engaging the androgen receptor pathway as intended. Worth stating clearly: this trial was in cancer patients receiving a drug designed to affect tumor biology, not healthy volunteers — but the liver-enzyme signal itself is a real, dose-related pharmacological effect worth taking seriously regardless of population.