RAD-140 — sold as testolone — is one of the most-searched compounds in the performance corner of the internet, and one of the least-studied. It is not a peptide and it is not a steroid: it is a small non-steroidal molecule that binds the androgen receptor, invented at Radius Health in 2011 and pushed into human testing for exactly one purpose, which was not building muscle.[3][1] Everything written about it as a physique drug is an extrapolation from rodents. Everything documented about it in people is, so far, mostly harm. This page lays out both halves precisely, because almost nothing else written about RAD-140 does.
What RAD-140 actually is
Testosterone acts on a single receptor — the androgen receptor (AR) — but that receptor sits in muscle, bone, prostate, skin, liver and brain. That is why anabolic steroids cannot separate the effect people want from the effects they do not. The selective androgen receptor modulator idea is to design a non-steroidal ligand whose shape, once bound, recruits a different set of coactivator proteins in different tissues — so the receptor behaves like an agonist in muscle and bone while behaving weakly, or not at all, in prostate. The selectivity is not in the receptor. It is in the tissue-specific machinery the drug–receptor complex assembles around itself.
RAD-140 was designed to that brief and characterised by its inventors at Radius Health across a set of preclinical anabolic models.[3] Because it is a small synthetic molecule rather than a chain of amino acids, it survives the stomach and is taken orally — the trait that made it a drug candidate, and also the trait that makes it easy to sell as a capsule to people who would never inject anything. Its measured half-life in humans is long, about 44.7 hours, which is why it was dosed once daily in trial.[1] If you want the class framing rather than the molecule, we cover it in peptides vs SARMs: they are entirely different chemical categories that get shelved together only because both are sold outside the pharmacy.
The only human trial ever run — and what it was for
RAD-140 has one entry on ClinicalTrials.gov. NCT03088527 was a phase 1, first-in-human, multi-part study of RAD140 in postmenopausal women with hormone-receptor-positive breast cancer. It ran from October 2017 to September 2020, is listed as completed, and has no results posted to the registry.[2] Radius Health was pursuing it as an oncology asset, and for a coherent reason: RAD-140 activates AR in breast cancer cells and, in patient-derived xenograft models, suppressed the oestrogen-receptor pathway including the ESR1 gene itself — a genuinely distinct mechanism against AR+/ER+ tumours.[4]
The trial was published in 2022. Twenty-two heavily pretreated women (21 of them AR-positive) received 50 mg, 100 mg or 150 mg once daily. The maximum tolerated dose was 100 mg. Target engagement was real: sex hormone-binding globulin fell in 18 of 18 evaluable patients and PSA rose in 16 of 20, and paired tumour biopsies confirmed AR engagement. Efficacy was thin — a 24-week clinical benefit rate of 18.2%, one partial response, and a median progression-free survival of 2.3 months.[1] RAD-140 has not advanced beyond that study.
Read the safety table and the picture sharpens considerably. The three most common treatment-emergent adverse events were all liver chemistries: elevated AST in 59.1% of patients, elevated ALT in 45.5%, and elevated total bilirubin in 27.3%. Grade 3 or 4 events occurred in 72.7%, most often AST/ALT elevation and hypophosphataemia.[1] These were women with metastatic cancer on prior therapy, so no single number transfers cleanly to a healthy 28-year-old. But this is the only controlled human liver-safety signal that exists for this molecule, and it points the same direction as every case report below.
Why “no human muscle trial” is a claim we tried hard to break
A negative claim is only worth printing if you attacked it from the other side, so here is exactly what we did. We pulled the entire PubMed corpus for RAD140 (41 records) and testolone (6 records) and read every title. We searched PubMed for RAD140 combined with randomized (0 records), for testolone combined with trial (0 records), and for RAD140 combined with muscle or lean body mass restricted to human studies — which returned two anti-doping methodology papers and nothing else. We queried ClinicalTrials.gov for both RAD140 and testolone: one registered study exists, the breast-cancer study above.[2]
Two near-misses are worth naming, because they are the closest anything comes and neither counts. First, RAD-140 has been given to healthy men in a research setting — six micro-dose excretion studies, five adult male volunteers each, run by anti-doping chemists to map urinary metabolites and detection windows.[8] That is a forensic study at sub-pharmacological doses; it measured what comes out in urine, not what happens to muscle. Second, a 2023 systematic review of SARM safety in healthy adults did find 18 clinical trials across the SARM class — but those trials tested other molecules, and the review’s RAD-140 content is case reports of harm.[17]
That distinction matters more than it looks. The SARM class can be tested properly in healthy people, and has been. Enobosarm was run through a 12-week double-blind placebo-controlled phase 2 trial in 120 healthy elderly men and postmenopausal women, with lean body mass measured by DXA as the primary endpoint and dose-dependent gains reported.[23] LGD-4033 was run through a placebo-controlled 21-day study in 76 healthy young men with full hormone and lipid panels.[22] Nobody has ever done the equivalent for RAD-140. That is not an accident of publishing — it is the whole point. Its developer took it into oncology and stopped.
What has and has not been tested in humans
| Question | Human evidence for RAD-140 |
|---|---|
| Does it engage the androgen receptor in people? | Yes — SHBG fell in 18/18 and PSA rose in 16/20 in the phase 1 trial; tumour biopsies confirmed engagement |
| Pharmacokinetics and half-life | Yes — half-life 44.7 h, supporting once-daily dosing (n = 22, oncology patients) |
| Urinary metabolites and detection window | Yes — six micro-dose excretion studies in healthy male volunteers, for anti-doping purposes |
| Does it increase lean body mass in healthy people? | Never tested. No trial of any phase, any size |
| Does it increase strength or physical function? | Never tested |
| Effect on testosterone, LH and FSH in men | Never measured in a trial — inferred from the SARM class and from case reports |
| Effect on HDL cholesterol | Never measured in a RAD-140 trial |
| Liver safety | Yes, and it is the worst finding: AST elevated in 59.1%, ALT in 45.5%, bilirubin in 27.3%; plus ≥8 case reports of drug-induced liver injury |
| Cardiac safety | No trial. Case reports of myocarditis, myopericarditis and heart failure |
| Long-term safety at any dose | Never tested |
The liver injury — the most important thing on this page
Search the case literature and a pattern repeats with uncomfortable consistency: a previously healthy young man, weeks to a few months of RAD-140, then jaundice, dark urine, pale stools, itching and right upper quadrant pain. The biochemistry is cholestatic — bilirubin and alkaline phosphatase carry the injury while transaminases lag — and where biopsies were taken they show canalicular cholestasis and biliary reactive change consistent with drug-induced liver injury.
Hormones, lipids and the heart
The phase 1 trial enrolled postmenopausal women, so it produced no data at all on what RAD-140 does to the male hypothalamic-pituitary-gonadal axis. What we have instead is mechanism plus the class. Anything that agonises the androgen receptor systemically feeds back on the pituitary and suppresses LH, FSH and endogenous testosterone. In the closest comparable human study, LGD-4033 given to 76 healthy young men for 21 days produced dose-dependent suppression of total testosterone, SHBG, HDL cholesterol and triglycerides, with FSH and free testosterone falling at the top dose.[22] That is a different molecule, and we flag it as such — but the mechanism is shared, and the direction is not in dispute.
There is a documented human case that closes the loop for RAD-140 specifically: a 40-year-old man developed bilateral gynaecomastia and biochemical hypogonadotropic hypogonadism after six months of performance supplements that were analytically confirmed to contain RAD-140 — alongside MK-677, cardarine, and undisclosed testosterone, oestradiol and growth hormone. Symptoms and hormones normalised after he stopped.[18] Note what that case demonstrates twice over: the endocrine harm, and the fact that nobody who buys these products knows what they are actually taking.
The cardiac reports are sparser but hard to ignore given who is affected. A young man developed acute myocarditis after self-medicating with RAD-140 for bodybuilding.[19] A 16-year-old boy developed myopericarditis after his first dose of testolone.[20] A further report describes SARM-abuse-induced heart failure attributed to RAD-140.[21] Individually these are anecdotes; collectively they are the only cardiac safety information that exists, because no trial has ever looked. If your baseline is a testosterone prescription rather than a bottle from a website, the comparison is not close — see what testosterone therapy actually does, where the risks are at least characterised in randomised trials and monitored by a clinician.
The preclinical record, graded as preclinical
The animal data is genuinely the interesting part of RAD-140, and it deserves to be described accurately rather than either inflated or dismissed.
- Anabolic activity in rodents and primates. The original Radius Health characterisation reports RAD-140 as a potent, orally bioavailable SARM active across several preclinical models of anabolic androgen action.[3] A 2025 study in male Sprague-Dawley rats found RAD-140 significantly increased muscle fibre cross-sectional area versus vehicle in unloaded controls — but added nothing on top of functional overload, and did not change cortical or trabecular bone architecture over 14 days.[6] That is a real anabolic signal, and a smaller one than the marketing implies.
- Neuroprotection in cells and rats. RAD-140 was as effective as testosterone at reducing apoptotic neuronal death in cultured hippocampal neurons via MAPK signalling, and protected hippocampal neurons in kainate-lesioned male rats while largely sparing prostate.[5] This is the source of every “RAD-140 is neuroprotective” claim online. It is a 2014 rat and dish study. It has never been followed into a human brain.
- The counterweight animal study nobody quotes. Ten weeks of RAD-140 in young and adult female mice failed to improve strength, reduced adaptive potential in young mice, and increased both frailty status and mortality risk compared with controls — leading the authors to conclude it may be more detrimental than beneficial for sarcopenia.[7] When a compound’s entire case is preclinical, the preclinical studies that go the wrong way are part of the case.
Preclinical anabolic data is the normal starting point for a drug, not a substitute for one. Dozens of compounds with better rodent data than RAD-140 have failed in humans. The honest statement is that RAD-140 probably does build muscle in people — it engages the androgen receptor, and androgen receptor agonists build muscle — and that nobody has measured how much, at what dose, or at what cost.
Not approved, banned in sport, and frequently not what the label says
Regulatory status. RAD-140 is not approved as a medicine in the United States, the European Union, or anywhere else. The FDA’s position is unusually blunt for the agency: SARMs are unapproved drugs, and “SARMs cannot be legally marketed in the U.S. as a dietary supplement or drug at this time.” The agency lists liver injury and acute liver failure, increased risk of heart attack or stroke, psychosis, infertility and testicular shrinkage among reported harms, and notes it has issued warning letters and pursued criminal actions against distributors.[27] The “for research use only” label on the bottle is a legal fiction, not a category.
Sport. SARMs sit in section S1.2, Other Anabolic Agents, of the WADA Prohibited List, with RAD140 named explicitly. They are prohibited at all times — in and out-of-competition — for every athlete, from elite to recreational.[28] Anti-doping laboratories have mapped RAD-140’s urinary metabolites precisely enough to distinguish deliberate use from supplement contamination, and detection windows extend well past the last dose.[8] If you are tested at any level, this is a sanction waiting to happen. Our guide to WADA-banned compounds covers how that list works in practice.
What is actually in the bottle. This is the finding that should end most purchasing decisions on its own. Researchers bought 44 products marketed online as SARMs and analysed them under WADA-approved chain-of-custody procedures. Only 23 (52%) contained any SARM at all. Seventeen (39%) contained a different unapproved drug — ibutamoren, GW501516 or SR9009. Four (9%) contained no active compound whatsoever. Eleven (25%) contained substances not on the label. And the amount matched the label in only 18 of 44 products (41%).[24] A UK analysis found the same class of discrepancy, from products with no active ingredient to products with undeclared prohibited analytes.[25] An Italian analysis of 13 online-purchased SARM products found the stated SARM present in about 70%, a different SARM instead in 23%, undeclared tamoxifen, clomifene, testosterone, methandienone or tadalafil in 30%, and measured content ranging from 30% to 90% of the label claim.[26]
Put that alongside the liver data and the risk compounds rather than adds. You are taking an unapproved compound with a documented hepatotoxicity signal, at a dose you cannot verify, possibly mixed with a second unapproved compound you did not choose. The gynaecomastia case above is exactly what that looks like when it goes wrong.[18] If muscle is the goal, the honest alternatives are unglamorous and legal — see what actually has evidence for muscle growth.
The bottom line
RAD-140 is a well-designed molecule that was taken into humans once, for cancer, and left there. There is no trial showing it builds muscle in healthy people, no trial measuring its effect on testosterone or HDL, no trial of any duration establishing that it is safe to take, and no regulator anywhere that has approved it. What does exist in humans is an adverse-event profile: liver enzyme elevation in the majority of patients in its only trial, at least eight published cases of drug-induced liver injury including one that required plasmapheresis and intensive care, and scattered reports of myocarditis, heart failure and hypogonadism — one of them in a 16-year-old after a single dose.
So the fair summary is not “promising but under-researched.” It is narrower and less comfortable than that: the only well-documented human effects of RAD-140 are its harms. The efficacy people are buying is an inference from rats; the liver injury is a matter of published record. And whatever you conclude about the molecule, the product you would actually receive has roughly even odds of not containing what the label says. There is no version of this where a careful reader ends up ordering it.
This article is research information, not medical advice, and not a protocol. RAD-140 (testolone) is an unapproved investigational compound: it has no marketing approval in any country, it cannot be legally sold in the United States as a dietary supplement or a drug, and “research use only” labelling does not make it lawful to consume. It is prohibited in sport at all times under WADA section S1.2, at every level of competition. Severe cholestatic drug-induced liver injury is documented in published case reports, including cases requiring hospitalisation, corticosteroids and plasmapheresis, and liver enzyme elevation was the leading adverse event in its only human trial. Products sold online as SARMs are frequently mislabelled, underdosed, or contain a different unapproved drug entirely. Anyone experiencing jaundice, dark urine, pale stools, itching, abdominal pain or chest pain after taking a performance product should seek medical care immediately and tell the clinician exactly what they took.