Testolone (RAD-140)
Testolone (RAD-140) is a potent non-steroidal SARM originally explored for breast cancer and muscle wasting. Human data are minimal, limited largely to an early oncology trial, so most claims are preclinical or anecdotal. Recreational users report strong strength and size gains alongside marked testosterone suppression, and case reports link it to liver injury.
01 Overview
RAD-140 was developed by Radius Health as a high-affinity androgen-receptor agonist, with a small oncology trial (RAD140 in AR-positive breast cancer) providing most of the limited human exposure data. Preclinical studies show robust anabolic and neuroprotective activity, but efficacy for physique or performance in humans is not established.
Among SARMs, RAD-140 is regarded anecdotally as one of the more potent and more suppressive. It is prohibited in sport, unapproved as a medicine, and has been named in published cases of drug-induced liver injury. All recreational dosing is extrapolated from anecdote rather than trials.
02 Mechanism
High-affinity selective androgen-receptor agonist with strong anabolic signalling in muscle and preclinical neuroprotective effects.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Light | 5–10 mg/day | Oral | Anecdotal starting range; no validated human dose exists. |
| Common | 10–20 mg/day | Oral | Higher anecdotal range associated with stronger suppression. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Increased muscle mass and strengthWidely reported by users; not demonstrated in controlled physique trials. | Anecdotal | ||
| Anabolic activity in muscleAnimal studies show significant increases in lean mass and androgen-receptor activation. | Preclinical | ||
| Neuroprotective activityCell and animal models suggest neuroprotective effects; unproven in humans. | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Lipid changes (HDL reduction)Users commonly report reduced HDL; not quantified in controlled human data. | Moderate | Common | Anecdotal | |
| Testosterone suppressionReported as markedly suppressive of endogenous testosterone, often requiring longer recovery than milder SARMs. | Severe | Near-universal | Anecdotal | |
| HepatotoxicityPublished case reports describe severe drug-induced liver injury attributed to RAD-140. | Severe | Uncommon | Observational |
06 Commonly used with
What testolone is combined with, and why. This is about intent rather than safety — the interactions table below covers what is dangerous. Nothing here is listed without what it costs.
| Compound | Frequency | Purpose & trade-off |
|---|---|---|
| Stacked compounds | ||
| Cardarinerecomp | A classic recomp pairing — testolone drives strength and lean mass while cardarine adds non-hormonal endurance and fat loss.Trade-off: Cardarine contributes rodent tumour risk and no human safety record, so the combination stacks an unknown on top of an already potent SARM. | |
| Ostarinerecomp | Ostarine is added as a gentler co-agent to round out muscle retention alongside testolone's stronger anabolic push.Trade-off: Both are suppressive, so combining them increases shutdown and the case for a full PCT rather than a token one. | |
| IbutamorenMK-677 | Stacked for GH-mediated recovery, sleep and appetite to support the surplus many run testolone in.Trade-off: Ibutamoren adds water retention, hunger and possible worsening of glucose handling without contributing to strength directly. | |
| Post-cycle | ||
| TamoxifenPCT | Testolone is among the more suppressive SARMs, so a SERM-based PCT is commonly run to aid testosterone recovery.Trade-off: A SERM does not guarantee full recovery from a potent, understudied compound and brings its own mood and vision side effects. | |