Androgen Receptor Modulators (SARMs)

AC-262,536, AC-262, AC262536, AC 262536

AC-262536 is a nonsteroidal selective androgen receptor modulator (SARM) that acts as a partial agonist at the androgen receptor. It is not a peptide and is not an approved medicine anywhere — it exists only as a preclinical research chemical, characterized in a single published animal/in-vitro study (PMID 18164613, J Steroid Biochem Mol Biol 2008) from ACADIA Pharmaceuticals. In castrated rats it produced roughly 66% of testosterone's anabolic (levator ani) effect at only ~27% of its prostate (androgenic) effect, reduced plasma LH, and inhibited DHT-driven proliferation of LNCaP prostate-cancer cells in vitro. There is no human efficacy or safety data of any kind, and it is prohibited in sport by WADA (S1.2). It is not an approved medicine and has never entered published human trials.

2-chloro-4-[(1R,5S)-3-hydroxy-3-methyl-8-azabicyclo[3.2.1]octan-8-yl]-3-methylbenzonitrile, 2-chloro-4-[(3-endo)-3-hydroxy-3-methyl-8-azabicyclo[3.2.1]oct-8-yl]-3-methylbenzonitrile, CAS 1048998-11-3 (alternate registry number in the 2025 forensic-tox literature; 899821-23-9 is the widely-documented primary)

ACP-105 is a nonsteroidal selective androgen receptor modulator (SARM) — a true SARM, not a peptide — discovered by ACADIA Pharmaceuticals and nominated as a development candidate around 2006. It is a potent partial agonist of the androgen receptor that was anabolic on muscle and bone with relative prostate-sparing in rodents, and was also explored around cognition in mice. Its evidence base is preclinical only: no human trials, no IND, and no ClinicalTrials.gov records. It is not an approved medicine anywhere, and it is prohibited in sport by WADA (class S1.2).

S-4, S4, GTx-007, GTX-007, Androxolutamide, Andarine

An investigational nonsteroidal selective androgen receptor modulator (SARM) — a small-molecule arylpropionamide with a nitro group, NOT a peptide. Developed by GTx as GTx-007 and regarded as likely the first SARM to enter human testing (about three Phase 1 studies, ~86 volunteers, ~2003–2004). Development was abandoned because of a dose-dependent visual disturbance — a yellow/amber tint to vision and impaired night/low-light adaptation, reversible on discontinuation. Never approved by any regulator. WADA-prohibited (S1.2).

PS-178990, BMS 564929, BMS564929, 2-Chloro-3-methyl-4-[(7R,7aS)-7-hydroxy-1,3-dioxo-5,6,7,7a-tetrahydropyrrolo[1,2-c]imidazol-2-yl]benzonitrile

A nonsteroidal selective androgen receptor modulator (SARM) of the bicyclic hydantoin (pyrrolo[1,2-c]imidazole-1,3-dione) class — a true SARM, NOT a peptide and NOT a steroid. Originated by Bristol-Myers Squibb and intended for age-related androgen decline in men. In castrated rats it is a subnanomolar AR agonist (Ki ~2.11 nM) with extreme muscle-versus-prostate tissue selectivity, but the same primary study flags potent luteinizing-hormone (LH) suppression and a narrow therapeutic index. Its evidence base is PRECLINICAL — ClinicalTrials.gov returns zero registered trials, and the widely repeated "early human clinical trials" claim is uncited and UNVERIFIED. There is no reliable human efficacy or safety data. WADA-prohibited (S1.2). Not an approved medicine anywhere (as of 2026-07-10).

DT-200, GLPG-0492, GLPG0492

GLPG0492 (also called DT-200) is a nonsteroidal, aryl-hydantoin selective androgen receptor modulator (SARM) developed by Galapagos NV — a small-molecule research compound, not a peptide, investigated for muscle-wasting conditions and Duchenne muscular dystrophy. Its most advanced human testing was Phase 1: three registered Phase 1 studies in healthy volunteers (a first-in-human single-ascending-dose study, a multiple-ascending-dose study, and a muscle-protein-synthesis pharmacodynamic study), the last completed April 2012. It never advanced to later-phase trials and was never approved for any use.

GSK2881078, GSK-2881078, GSK 2881078

A nonsteroidal, orally active selective androgen receptor modulator (SARM) developed by GlaxoSmithKline as an investigational treatment for muscle wasting and weakness — NOT a peptide and NOT an anabolic steroid. It reached Phase 2 (first-in-human study, Clark et al., Br J Clin Pharmacol 2017, PMID 28449232; and a 13-week Phase 2 trial in COPD, Thorax 2022, PMID 36283827, NCT03359473), where it raised lean body mass by ~2 kg with a strength signal in men — while the same trials documented the class-defining risks: transient liver-enzyme (transaminase) elevations, reduced HDL cholesterol and SHBG, and dose-dependent testosterone suppression in men. It is NOT an approved medicine for any use.

LG-121071, LGD-121071, 4-ethyl-1,2,3,4-tetrahydro-6-(trifluoromethyl)-8-pyridono[5,6-g]-quinoline

LG121071 is an early nonsteroidal selective androgen receptor modulator (SARM) developed by Ligand Pharmaceuticals and first described in 1999 (Hamann et al., J Med Chem, PMID 9925725) — a true nonsteroidal SARM built on a tricyclic tetrahydroquinolinone (trifluoromethyl-quinolinone) scaffold, NOT a peptide and NOT a steroid. It is historically important as among the FIRST orally active nonsteroidal androgens ever described and is a chemical predecessor to Ligand's later LGD series (including ligandrol / LGD-4033). It is reported as a high-affinity full agonist of the androgen receptor (Ki ~17 nM) with potency described as comparable to dihydrotestosterone (DHT), and, being nonsteroidal, it is not a substrate for 5alpha-reductase or aromatase. It has NO human trials, is NOT approved by any regulator, and exists only as a preclinical research compound and analytical reference material. It is prohibited in sport under WADA class S1.2 (SARMs); an in-vitro metabolism and urinary detection method was published in 2015 (Knoop et al., PMID 25906032) because it could be misused as a doping agent. It is NOT an approved medicine.

LGD2226, LGD 2226

LGD-2226 is a nonsteroidal selective androgen receptor modulator (SARM) and a bicyclic 6-anilino-quinolinone small molecule — not a peptide — discovered by Ligand Pharmaceuticals as a candidate for muscle wasting and osteoporosis. All evidence is preclinical (animal/in-vitro); it was never approved as a medicine and, on the available record, most likely never completed a Phase 1 human trial.

LGD 2941, LGD2941, DB05234

LGD-2941 is a nonsteroidal selective androgen receptor modulator (SARM) of the quinolinone (6-anilino-quinolinone) chemotype — it is NOT a peptide and NOT an approved medicine. It was originated by Ligand Pharmaceuticals and taken into Phase 1 under a collaboration with TAP Pharmaceutical Products; single-dose pharmacokinetic and adverse-event data in healthy volunteers were presented at ENDO 2008, after which development was discontinued (the SARM agreement was assigned to Abbott in 2008) and Ligand pivoted its SARM program to LGD-4033. Preclinical rodent findings suggested oral anabolic activity in muscle and bone with a reduced prostate effect, but these are animal data and do not establish human efficacy or safety. It is prohibited in sport under WADA S1.2 and is encountered today only as a research reagent. This entry is informational only and is a discontinued investigational drug, never approved for any use.

LGD3303, LGD 3303, 9-Chloro-2-ethyl-1-methyl-3-(2,2,2-trifluoroethyl)-3H-pyrrolo[3,2-f]quinolin-7(6H)-one

LGD-3303 is a true nonsteroidal selective androgen receptor modulator (SARM) of the pyrrolo-quinolinone class, synthesized by Ligand Pharmaceuticals — it is NOT a peptide and NOT a steroid. Its entire evidence base is preclinical (rodent and in-vitro, ~2008–2009); it never entered human trials. In animals it showed a functionally dissociated profile (full agonist for muscle/bone, partial agonist for prostate). Not approved by any regulator anywhere; sold only as an illicit research chemical.

LGD-4033, VK5211, Anabolicum

Ligandrol (LGD-4033) is a nonsteroidal selective androgen receptor modulator (SARM) — it is NOT a peptide. It is a synthetic pyrrolidinyl-benzonitrile that binds the androgen receptor as a tissue-selective agonist/partial agonist, producing anabolic effects in muscle and bone. Not approved for human use anywhere; investigational and sold only as a research chemical.

LY-305, LY 305, 2-chloro-4-[[(1R,2R)-2-hydroxy-2-methylcyclopentyl]amino]-3-methylbenzonitrile

LY305 is a true nonsteroidal selective androgen receptor modulator (SARM) of the benzonitrile class, developed de novo by Eli Lilly and engineered specifically for transdermal (gel) delivery. It is not a peptide, and it is a distinct molecule from Lilly's LY2452473 / OPK-88004 — the two should not be conflated. LY305 is an investigational research compound and is not an approved medicine anywhere.

MK 3984, MK3984

MK-3984 is a nonsteroidal selective androgen receptor modulator (SARM) developed by Merck — an aryl-propanamide (diarylpropanamide) small molecule in the same chemical family as ostarine and andarine, and explicitly not a peptide and not a steroidal (4-azasteroid) compound. Human data are limited to a single reported 12-week Phase 2 trial in 88 postmenopausal women (an ENDO 2010 conference presentation / GTx company release, with no ClinicalTrials.gov registration located), in which MK-3984 matched ostarine on lean-mass gain but caused a compound-specific liver-enzyme signal. Development was discontinued around 2010 when Merck exited the SARM field, and it is not an approved medicine anywhere.

MK4541, MK 4541

A preclinical, orally active STEROIDAL androgen-receptor ligand (a 4-azasteroid) developed by Merck & Co. — NOT a peptide and NOT a clean anabolic SARM. It is a dual/mixed AR modulator that is anabolic (agonist) in muscle and bone but ANTAGONIST (antiandrogenic) in the prostate, is also a 5α-reductase inhibitor, and strongly suppresses circulating testosterone. In cell and rodent studies it induced death of androgen-independent AR-positive prostate-cancer cells while sparing normal cells, and was explored as an adjuvant to androgen-deprivation therapy. It never reached human trials and is not an approved medicine anywhere; it is a research reagent only (as of 2026-07-10).

LY2452473, LY-2452473, TT-701, TT701, OPK 88004

OPK-88004 is one small-molecule nonsteroidal selective androgen receptor modulator (SARM) that carried three code names across three companies (Eli Lilly's LY2452473, Transition Therapeutics' TT-701, OPKO Health's OPK-88004); it acts as an androgen-receptor agonist in muscle and bone but an antagonist in the prostate. It is not a peptide and not a steroid. It is not an approved medicine anywhere and development stalled at Phase 2.

Enobosarm, MK-2866, MK2866, GTx-024, GTx024, S-22, Ostarine, Ostabolic

An orally active, nonsteroidal selective androgen receptor modulator (SARM) of the arylpropionamide class — NOT a peptide and NOT an approved medicine. Originally developed by GTx (later Oncternal, then licensed to Veru) and studied for muscle wasting, osteoporosis, and androgen-receptor-positive breast cancer. Its Phase 3 POWER1/POWER2 trials in non-small-cell-lung-cancer muscle wasting missed their co-primary endpoints, and a Phase 2 stress-urinary-incontinence trial (ASTRID) failed. Enobosarm has reached Phase 3 in AR+/ER+ breast cancer but is not approved anywhere. On the grey market it is the most-sold SARM and the single most common supplement-contamination culprit; documented harms include drug-induced liver injury and testosterone/HPTA suppression.

PF-06260414, PF 06260414, PF06260414, 6-[(4R)-4-methyl-1,1-dioxo-1,2,6-thiadiazinan-2-yl]isoquinoline-1-carbonitrile

A nonsteroidal selective androgen receptor modulator (SARM) — a small synthetic molecule (thiadiazinane-substituted isoquinoline-carbonitrile, C14H14N4O2S, CAS 1612755-71-1, PubChem CID 76071881), NOT a peptide — developed by Pfizer. It reached a single completed Phase 1 first-in-human study in healthy men (NCT02070939; Bhattacharya et al., Clin Ther 2016, PMID 27085586) and shows no public development beyond Phase 1. It is NOT an approved medicine for any use, including muscle growth, physique, or performance.

RAD-150, RAD 150, TLB-150, TLB150, TLB-150 Benzoate, TLB 150 Benzoate, RAD-140 benzoate, testolone benzoate

RAD150 (TLB-150) is the benzoate ester of RAD-140 (testolone) — a nonsteroidal selective androgen receptor modulator (SARM) prodrug, NOT a peptide. It is designed so that endogenous esterases cleave the benzoate group in vivo to release the active AR modulator RAD-140, and it is sold on the grey research-chemical market as a "longer-lasting" RAD-140. There is NO peer-reviewed pharmacology or pharmacokinetic study of the ester itself, so its risk profile must be assumed to match RAD-140's documented drug-induced liver injury and testosterone suppression. It is NOT an approved medicine — it has never entered any registered clinical trial and is WADA-prohibited (S1.2).

GTx S-1, S1 (arylpropionamide SARM), (2S)-3-(4-fluorophenoxy)-2-hydroxy-2-methyl-N-[4-nitro-3-(trifluoromethyl)phenyl]propanamide

An early preclinical nonsteroidal selective androgen receptor modulator (SARM) of the arylpropionamide class — a small molecule, NOT a peptide and NOT a steroid. Developed by James T. Dalton, Duane D. Miller and colleagues at the University of Tennessee / GTx, Inc., S-1 is a close structural analog of andarine (S-4) from the same patent series. In castrated rats it bound the androgen receptor with nanomolar affinity and showed tissue-selective anabolic activity (levator ani muscle over prostate) without significant LH/FSH suppression near its ED50. It was an early lead; the program ultimately advanced enobosarm (ostarine), not S-1. No human trials were identified. Not approved by any regulator anywhere; WADA-prohibited (S1.2).

S 101479, S101479

S-101479 is a nonsteroidal selective androgen receptor modulator (SARM) — a synthetic small molecule of the tetrahydro/pyrrolo[3,2-c]quinoline class, NOT a peptide and NOT a steroid. It was developed by KAKEN Pharmaceutical (Japan) and studied preclinically as a potential bone-anabolic treatment for osteoporosis. Its entire evidence base is preclinical (ovariectomized-rat models and in-vitro cell/molecular work); no human clinical trials could be found (0 trials). It is NOT an approved medicine anywhere.

Mastorin, S23, S 23

A nonsteroidal selective androgen receptor modulator (SARM) of the arylpropionamide class — a true SARM, NOT a peptide and NOT a steroid. Developed preclinically by GTx, Inc.; it never entered a clinical trial and has no approved medical use. In rats it binds the androgen receptor with very high affinity (Ki ~1.7 nM) and its defining preclinical finding is dose-dependent, fully reversible suppression of spermatogenesis to azoospermia — it was studied as a candidate reversible male contraceptive. There is no human safety, efficacy, or dosing data; WADA prohibits it by name (S1.2). Not an approved medicine anywhere (as of 2026-07-10).

S 40503, S40503

A nonsteroidal selective androgen receptor modulator (SARM) developed preclinically by Kaken Pharmaceutical (Japan) — a true SARM, NOT a peptide and NOT an anabolic steroid. It was studied only in rat models of osteoporosis, where its defining feature was a bone-first anabolic profile: in castrated male rats it raised femoral bone mineral density and levator-ani muscle mass like DHT while, notably, NOT increasing prostate weight, and in ovariectomized female rats it increased bone density and cortical-bone strength. It is often described as a lead/prototype compound to seed derivatives with better bioavailability rather than a drug candidate itself; there are no known human trials, no human safety or pharmacokinetic data, and it is WADA-prohibited (S1.2). Do NOT confuse it with andarine (S-4). It is NOT an approved medicine anywhere (as of 2026-07-10).

RAD-140, RAD140, Testolone, Vosilasarm, EP0062, EP-0062

A synthetic, orally active nonsteroidal selective androgen receptor modulator (SARM) — NOT a peptide — originally developed by Radius Health (as RAD140) and now advanced by Ellipses Pharma as vosilasarm (EP0062) for AR+/ER+/HER2- breast cancer. It reached Phase 1 in oncology and is in an ongoing Phase 1/2 trial (NCT05573126, NCT03088527). It is NOT an approved medicine. Its defining safety signal is the liver — the first-in-human RAD140 trial (n=22) reported treatment-emergent elevated AST in 59% and ALT in 46% of patients [NCT03088527], the reformulated vosilasarm Phase 1 saw transient Grade-3 ALT increases in about 20% [ASCO 2025, JCO 43:16_suppl:1057], and multiple published case reports link grey-market RAD-140 to drug-induced liver injury — the strongest DILI signal among the common SARMs. WADA-prohibited (S1.2).

PubChem CID 10277123, HY-103246, CS-0026116, (1S,3aS,3bS,5aR,9aR,9bS,11aS)-6,9a,11a-trimethyl-7-oxo-N-[2-(trifluoromethyl)phenyl]-2,3,3a,3b,4,5,5a,9b,10,11-decahydro-1H-indeno[5,4-f]quinoline-1-carboxamide

A preclinical, STEROIDAL selective androgen receptor modulator (SARM) — specifically a 4-azasteroid — that is NOT a peptide and NOT one of the familiar nonsteroidal arylpropionamide SARMs (e.g. ostarine, RAD140). Described by Merck medicinal chemists (Schmidt et al., J Biol Chem 2009; PMID 19846549) as a dual mechanistic agent: a partial agonist of the androgen receptor (AR binding IC50 ~30-38 nM; Emax ~55%) that also inhibits both 5α-reductase type I and type II (IC50 ~2 and ~3 nM). In its AR N-terminal/C-terminal (N/C) interaction assay it behaves as an antagonist, which is thought to underlie its gene- and tissue-selective profile. In ovariectomized rats it built bone and muscle comparable to DHT while only weakly stimulating prostate growth, stimulating sebaceous glands only ~31% as much as DHT, and partially antagonizing DHT-driven seminal-vesicle growth. It is a research-reagent / probe compound with NO human trial or human safety data of any kind; a structurally related successor (MK-0773) was advanced further by Merck. WADA-prohibited (S1.2). It is NOT an approved medicine anywhere (as of 2026-07-10).

YK11, YK 11, Myostine, (17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester

A synthetic steroid — derived from 19-norprogesterone and structurally a gene-modified DHT-type steroid — that is marketed and even WADA-listed as a "SARM," but is mechanistically neither a peptide nor a classic nonsteroidal SARM. It acts as a partial agonist of the androgen receptor, and its muscle-building signal is driven chiefly by inducing follistatin in muscle cells, which indirectly suppresses myostatin (it does NOT bind or inhibit myostatin directly). It is NOT an approved medicine — all efficacy data are in vitro (C2C12 myoblasts) or animal, and it should be framed strictly as a research reagent.