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S233.0
S-23 Research
Mostly mechanism / observational
9 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most S-23 studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from medium-quality studies published 2009–2025 with a typical study size of 970 participants.
Based on 9 studies · 1,042 total participants
Confidence
Low confidence
By outcome
Androgen & hormonal axis
Mostly mechanism / observational8 studies
Safety profile
Mostly mechanism / observational6 studies
Body composition (rats only)Increased lean mass and bone in rats; no human efficacy or safety data, with marked HPTA/fertility suppression. · Not established (no human trials)
Mostly mechanism / observational4 studies
Fertility suppression (contraceptive effect)
Too few graded studies1 study
Active research area
8 studies in the last 5 years
200920172025
1Systematic Reviewn=970 · large study2025
In plain English: Conclusion SARMs have a positive effect on physical performance and body composition and are associated with moderate rates of mild to moderate adverse effects (AEs) and a low rate of severe AEs.
Wen J, Syed B, Leapart J, Shehabat M, Ansari U, Akhtar M, Razick D, Pai D. · Clinical endocrinology (2025)
Six SARMs were analysed: LGD-4033, PF-06260414, GSK2881078, GTx-024, MK-0773 and OPK-88004.
Mean post-intervention values were 315.16 W (89.46-525.73 W), 2191.27 N (1375.87-2462.9 N), 9.79 (8.88-10.4), 50.86 kg (31.02-67.29) and 21.85 kg (12.54-32.16), respectively.
Conclusion SARMs have a positive effect on physical performance and body composition and are associated with moderate rates of mild to moderate adverse effects (AEs) and a low rate of severe AEs.
In plain English: Therefore, more detailed analyses are needed to determine the safety of using SARMs.
Leciejewska N, Jędrejko K, Gómez-Renaud VM, Manríquez-Núñez J, Muszyńska B, Pokrywka A. · European journal of clinical pharmacology (2024)
Limited data are related to the dosages and purity of SARM supplements.
Conclusion Promoting SARMs as an anabolic agent in combination with other performance-enhancing drugs poses a risk to users not only due to doping controls but also to health safety.
The lack of quality control of consumed supplements makes it very difficult to assess the direct impact of SARMs on the liver and their potential hepatotoxic effects.
In plain English: This holds especially true when taking SARMs without supervision by a medical professional, which should consist of a thorough monitoring of liver enzyme and bilirubin levels.
Mertens JE, Bömmer MTC, Regier MB, Gabriëls G, Pavenstädt H, Grünewald I, Horvath J, Trebicka J, Schmidt H, Schlevogt B. · Zeitschrift fur Gastroenterologie (2024)
Nevertheless, three common heterozygous polymorphisms associated with an increased risk for intrahepatic cholestasis could be identified.
Our case demonstrates that SARMs can cause severe liver injuries not prominently mentioned in safety data sheets.
Therefore, these compounds constitute a potential danger to the user's health.
In plain English: Athlete SARM abuse is increasingly widespread and unsafe, and public health oversight bodies should advocate for regulation of these gray-market compounds.
Vasireddi N, Hahamyan HA, Gould HP, Gregory AJM, Gausden EB, Dodson CC, Voos JE, Calcei JG. · The American journal of sports medicine (2025)
The prevalence of SARM use among athletes is estimated to be 1% to 3%.
SARM preclinical and clinical studies reported significant increases in lean body mass and side effects-including bone remodeling, testosterone suppression, and kidney, liver, and prostate enlargement.
Conclusion The results of this systematic review serve to educate sports medicine clinicians and researchers on how to better identify, diagnose, and treat athlete SARM abuse.
5Spermatogenesis suppression and body compositionAnimal2009
In plain English: This is the first study to show that a selective androgen receptor modulator combined with EB is an effective and reversible regimen for hormonal male contraception in rats.
Jones A, Chen J, Hwang DJ, Miller DD, Dalton JT · Endocrinology (2009)
Foundational S-23 paper — high androgen-receptor binding affinity (Ki ~1.7 nM) and full-agonist activity in vitro
In intact male rats, suppressed LH (>50%) and, with estradiol benzoate, suppressed FSH and spermatogenesis: four of six rats had no sperm and zero pregnancies in mating trials
Increased bone mineral density and lean mass and reduced fat mass dose-dependently — the basis for its grey-market body-composition use
6Label accuracy of SARM-marketed supplementsIn Vitro2021
In plain English: This study found discrepancies ranging from a supplement in which no active ingredients were found, to supplements containing undeclared prohibited analytes.
Leaney AE, Beck P, Biddle S, Brown P, Grace PB, Hudson SC, Mawson DH · Drug testing and analysis (2021)
Purchased and chemically analyzed consumer products marketed as SARMs (the grey market S-23 is sold in)
Found pervasive mislabeling — products with no active ingredient, undeclared prohibited analytes, and doses differing from the label
No SARM has met the safety/efficacy bar for FDA or EMA approval; products are illegally marketed as supplements
In plain English: It is shown that SARMs may increase the risk of cardiovascular diseases ... There is a noticeable lack of clinical trials and literature on the relationship between SARMs, cardiovascular diseases, and the AR.
Hall E, Vrolijk MF · Nutrients (2023)
Review of androgen-receptor pharmacology and the cardiovascular risk of abusing SARM-containing supplements
Notes SARM abuse may raise cardiovascular risk via the renin-angiotensin system, lipid profile, inflammation, platelet activity, and other pathways
Emphasizes the near-total absence of clinical trials on SARMs and cardiovascular outcomes
In plain English: To the best of the authors knowledge, this seems to be the first study ever achieved on S-23 [in humans] ... nothing has been published about long-term effects of S-23.
Ameline A, Gheddar L, Raul JS, Kintz P · Journal of pharmaceutical and biomedical analysis (2022)
Single ~8 mg oral dose of S-23 in one human volunteer, used to characterize urinary metabolites for anti-doping — a detection study, not an efficacy or safety study
S-23 was detectable in urine from 2 h up to 28 days post-administration
Explicitly notes very few data exist and nothing is published on the long-term effects of S-23
9Urinary elimination profile of microdosed S-23Observational2025
In plain English: Among these, S-23 has been identified in five AAFs reported in 2022 ... inadvertent exposure through contaminated dietary supplements has emerged as a significant concern.
Alhalabi H, Korsmeier L, Thomas A, Thevis M · Biomedical chromatography : BMC (2025)
Microdose (1, 10, 50 µg) human administration study characterizing S-23 urinary elimination for doping control
S-23 was responsible for five adverse analytical findings (positive doping tests) in athletes in 2022
Highlights contaminated dietary supplements as a route of inadvertent S-23 exposure