Selective Androgen Receptor Modulators (SARMs) are among the most-discussed compounds in modern performance and endocrine science. This guide explains what they are, which classes exist, what the published research actually shows, and how their legal and regulatory status is defined in the UK and EU — presented strictly as laboratory and educational information, without the hype.
What are SARMs?
SARMs are a class of investigational compounds designed to interact selectively with androgen receptors in particular tissues, such as skeletal muscle and bone, while exerting comparatively less activity in other tissues like the prostate. The concept was introduced in the late 1990s to explore whether the anabolic (tissue-building) signalling of androgens could be separated from broader androgenic effects. Unlike anabolic-androgenic steroids, most SARMs are non-steroidal molecules. In laboratory study they are handled as research chemicals, not as medicines or supplements.
What are the main classes of SARMs?
SARMs are not a single substance but a family of structurally distinct chemotypes investigated by different research groups. Reported structural classes include aryl-propionamide analogues, quinolinone analogues, hydantoin analogues, and indole and tetrahydroquinoline derivatives. Compounds frequently named in the scientific literature include enobosarm (also referred to as ostarine or MK-2866), ligandrol (LGD-4033), andarine, and RAD140. Each candidate differs in its reported receptor-binding profile and tissue selectivity, which is one reason researchers study them as distinct entities rather than as interchangeable agents.
What does the research show?
Published reviews describe SARMs as binding the androgen receptor and showing anabolic activity on muscle and bone in preclinical and some early-phase clinical models, with the aim of reduced activity on secondary sexual tissue. However, a 2025 critical appraisal in Frontiers in Endocrinology concluded that, despite decades of development, SARMs have not yet delivered truly tissue-selective effects in humans, and that the absence of head-to-head trials makes strong comparative claims difficult to substantiate. The evidence base remains preliminary and is the active subject of ongoing research.
Are any SARMs approved medicines?
No. As of 2026, no SARM has completed the full clinical-trial and approval process required to become a licensed medicine. SARMs have not been approved or evaluated as medicines by the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK, the European Medicines Agency (EMA), or the U.S. Food and Drug Administration (FDA). They are therefore unapproved investigational compounds. Any material referenced here is discussed for laboratory research and educational purposes only, not as a treatment for any condition.
How do SARMs differ from peptides?
Researchers often compare SARMs with research peptides because both are studied in performance and recovery contexts, yet they are chemically and mechanistically distinct. The table below summarises the key differences as described in the literature. It is provided for educational comparison only and does not imply that either category is approved for human use.
| Property | SARMs | Research peptides |
|---|---|---|
| Chemical nature | Mostly small non-steroidal molecules | Short chains of amino acids |
| Primary target | Androgen receptor | Varies by peptide (e.g. specific receptors or signalling pathways) |
| Typical lab handling | Often oral-format research solutions or powders | Usually reconstituted lyophilised powder |
| Regulatory status | Not approved as medicines (MHRA/EMA/FDA) | Most are not approved as medicines |
| Anti-doping status | Prohibited in sport at all times (WADA S1.2) | Many classes also prohibited in sport |
Is it legal to buy SARMs in the UK?
In the UK, SARMs are not controlled substances under the Misuse of Drugs Act, and they are commonly supplied as research chemicals for laboratory use. They are not licensed medicines and cannot lawfully be marketed, labelled, or sold for human consumption or as dietary or food supplements. Regulators including the MHRA have taken enforcement action against businesses marketing SARMs for human use. This article does not constitute legal advice; researchers should confirm current obligations for their own jurisdiction and intended use.
Are SARMs banned in sport?
Yes. The World Anti-Doping Agency (WADA) classifies SARMs as prohibited anabolic agents under section S1.2 (“other anabolic agents”) of its Prohibited List. They are banned at all times, both in and out of competition, for athletes at every level. Named examples on the list include andarine, enobosarm (ostarine), LGD-4033 (ligandrol), RAD140, S-23, and YK-11, and any related SARM would be treated as prohibited. Athletes subject to testing should treat all SARMs as banned.
Why does purity and third-party testing matter in research?
In any laboratory setting, results are only as reliable as the material studied. A compound verified at 99%+ purity behaves very differently from one at 80%, and impurities can confound experimental data. That is why every batch we supply is independently analysed by Janoshik Analytical, with a Certificate of Analysis (COA) available on request.
How do you read a Certificate of Analysis?
A good COA states the compound identity, the measured purity percentage (typically via HPLC), and the testing date, ideally tied to a specific batch. If a supplier cannot produce a COA, their purity claims should be treated with caution. You can review our verified batches on the Lab Tests page. Different compounds are studied for different research questions, and our Bioreactive Series carries our highest Reactive scores.
Research references
- Narayanan R, Mohler ML, Bohl CE, Miller DD, Dalton JT. “Selective androgen receptor modulators in preclinical and clinical development.” Nuclear Receptor Signaling. 2008;6:e010. DOI: 10.1621/nrs.06010
- Bond P, Smit DL, Verdegaal T, de Ronde W. “Selective androgen receptor modulators: a critical appraisal.” Frontiers in Endocrinology. 2025;16:1634799. DOI: 10.3389/fendo.2025.1634799
- U.S. Anti-Doping Agency (USADA). “What Athletes Need to Know about Selective Androgen Receptor Modulators (SARMs)” (WADA Prohibited List, class S1.2). usada.org
For laboratory research and educational purposes only. Not for human consumption and not intended to diagnose, treat, cure, or prevent any disease. SARMs are not approved medicines and have not been evaluated by the MHRA, EMA, or FDA.