RAD-140 (Testolone) for Muscle Mass & Strength — SARMs
Most potent non-steroidal SARM for lean mass and strength gains. Developed by Radius Health. Phase I clinical trial completed. NOT FDA-approved.
Overview
RAD-140 (Testolone) is a non-steroidal selective androgen receptor modulator (SARM) developed by Radius Health Inc. for potential treatment of breast cancer and muscle wasting conditions. It is widely considered the most potent SARM available for muscle mass and strength enhancement. RAD-140 demonstrates high affinity and selectivity for the androgen receptor (AR) in skeletal muscle and bone tissue, with significantly reduced androgenic activity in the prostate and seminal vesicles compared to testosterone. Preclinical studies demonstrated an anabolic-to-androgenic ratio exceeding 90:1, making it one of the most tissue-selective compounds in its class. A Phase I clinical trial (NCT03088527) in postmenopausal women with breast cancer was completed in 2020, establishing preliminary safety and pharmacokinetic parameters. RAD-140 exhibits an exceptionally long elimination half-life of approximately 60 hours, allowing for once-daily oral dosing. The compound demonstrates dose-dependent suppression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), leading to significant endogenous testosterone suppression even at low doses (10mg/day). Hepatotoxicity has been reported in case studies, including drug-induced liver injury (DILI) with cholestatic pattern (PMID: 31365801, PMID: 32359652). RAD-140 is NOT FDA-approved for any indication and is explicitly prohibited by WADA for athletic competition. It remains an investigational compound with limited human safety data. All use outside of clinical trials constitutes off-label experimentation with unknown long-term risks.
Indications
- Investigational treatment for hormone receptor-positive breast cancer (Phase I)
- Research into skeletal muscle wasting prevention in cancer and aging
- Potential neuroprotective applications (preclinical evidence of AR-mediated neuronal protection)
- Investigation of bone density enhancement in osteoporosis models
- Research compound for androgen receptor biology studies
- Potential treatment for sarcopenia in elderly populations (preclinical)
Mechanism of Action
RAD-140 is administered orally with high bioavailability. The non-steroidal structure allows efficient GI absorption without first-pass destruction. Long half-life (~60hrs) provides sustained plasma levels with once-daily dosing
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| RAD-140 (Testolone) | 10 mg/day | Once daily | Beginner dose; significant suppression still expected |
| RAD-140 (Testolone) | 15-20 mg/day | Once daily | Intermediate dose; increased efficacy with greater suppression |
| RAD-140 (Testolone) | 20-30 mg/day | Once daily | Advanced dose; maximal suppression, higher hepatotoxicity risk |
Evidence Grade
GRADE D
Safety & Contraindications
- NOT FDA-approved for any human indication — all use is experimental
- Significant LH/FSH suppression leading to hypogonadism — PCT required post-cycle
- Drug-induced liver injury (DILI) reported — cholestatic hepatitis pattern (PMID: 31365801)
- Dose-dependent testosterone suppression even at 10mg/day
- Unknown long-term cardiovascular safety profile
- Potential lipid dysregulation — HDL suppression observed in anecdotal reports
- Hair loss acceleration possible in androgenetically predisposed individuals
- WADA prohibited substance — banned in all sanctioned athletics
- No established antidote or reversal agent for adverse effects
- Potential drug interactions with CYP3A4 substrates (preliminary data)
- Contamination risk with gray-market products — no pharmaceutical-grade supply
- Long half-life (~60hrs) means prolonged detection window and slow clearance of adverse effects