RAD-140 (Testolone)
EmergingMost potent of the common SARMs — strong body comp gains but the harshest HPG suppression in the class plus documented hepatotoxicity case… | SARM · Oral
Aliases (2)
▸ Cycle structure & PCT AAS oral
Ramp dose over week 1, hold steady through cycle weeks. Track baseline labs (TT/FT/E2/SHBG/HCT/lipids/LFTs) at week 0; recheck at week 4 and end-of-cycle.
On the last dose, the ester clears over its half-life window (enanthate = est. 7 days). PCT begins after the active compound has cleared.
Standard PCT is enclomiphene 12.5-25 mg/day or clomid 50/50/25/25 over 4 weeks (or nolvadex 20/20/10/10). HCG bridge optional during cycle to preserve testicular volume + faster restart. Bloodwork at PCT week 4 + 8 to confirm HPG axis recovery (LH, FSH, TT back to baseline).
▸ Overview TL;DR
Most potent of the common SARMs — strong body comp gains but the harshest HPG suppression in the class plus documented hepatotoxicity case reports. SKIP-AT-20: brain-priority profile + AR-mediated endocrine disruption during a developmental window = no-go regardless of training goals.
▸ Mechanism of action
RAD-140 is a non-steroidal small-molecule androgen receptor (AR) agonist developed by Radius Health. It binds AR with high affinity and selectivity, producing strong anabolic effects in muscle and bone while in theory sparing prostate/skin tissue. In practice the "selectivity" claim breaks down at performance doses: AR signaling in the hypothalamus and pituitary still triggers negative feedback, suppressing LH and FSH and shutting down endogenous testosterone production. The original clinical program targeted ER+ breast cancer (acting as an AR agonist in androgen-receptor-positive breast tumors); that trial was halted, with safety/efficacy concerns ending the development program.
▸ Pharmacokinetics No data
▸Quality indicators4 checks
▸ What to expect From notes
- 1Onset(week 1-2): Increased aggression, drive, gym output. "Wired" feel that some users like, others find irritable.
- 2Peak(week 3-6): Significant body composition shift — lean mass gain, fat loss, strength jumps that exceed natur…
▸ Side effects + safety
- Common (>10% users): HPG suppression (near-universal at 10mg+), libido changes (initial increase then crash), headaches, aggression/irritability, lipid shifts (HDL drops, LDL rises), elevated liver enzymes (mild-moderate ALT/AST elevation common).
- Less common (1-10%): Hair shedding (AR activation in scalp follicles), acne, sleep disruption, hypertension, gynecomastia (from estrogen rebound or aromatization of recovered T post-cycle).
- Rare-serious (<1% but worth knowing): Drug-induced liver injury (DILI) — published case reports of cholestatic hepatitis requiring hospitalization, some with prolonged recovery. Cardiomyopathy concerns (animal data + case reports). Severe long-term HPG axis dysfunction in some users requiring TRT.
- Specific watch periods: Liver enzymes at week 4 and week 8; lipids at week 8; full hormone panel at week 12 (post-cycle, after PCT).