Selective Androgen Receptor Modulators — commonly known as SARMs — have become one of the most actively researched classes of compounds in preclinical science. Their ability to interact with androgen receptors in a tissue-selective manner has made them a focal point of academic studies exploring muscle wasting, bone density, and hormonal health.
This guide covers everything researchers need to understand about SARMs: their mechanism of action, how they differ from traditional anabolic steroids, the specific compounds currently under investigation, and where the science currently stands. All information is presented strictly for educational and research reference purposes.
What Are SARMs?
SARMs (Selective Androgen Receptor Modulators) are a class of compounds that bind to androgen receptors — the same receptors targeted by testosterone and other anabolic steroids — but do so in a tissue-selective manner. Unlike traditional androgens, which activate androgen receptors broadly across the body (muscle, bone, liver, prostate, skin), SARMs are designed to activate receptors preferentially in specific tissues.
This selectivity is the central premise of SARM research. The goal, as explored in numerous peer-reviewed studies, is to achieve anabolic effects in muscle and bone tissue while minimizing activity in tissues where androgen stimulation may be undesirable. Each SARM compound has its own unique selectivity profile, which is why researchers study them individually rather than as a single class.
How SARMs Work: Mechanism of Action
Androgen receptors are nuclear receptors — proteins inside cells that, when activated by androgens like testosterone, move into the cell nucleus and bind to specific DNA sequences called androgen response elements. This binding initiates transcription of genes involved in protein synthesis, cell growth, and differentiation.
Traditional anabolic steroids activate this process powerfully but non-selectively. SARMs interact with the same receptor but produce different structural changes in the receptor-ligand complex. Different ligands cause the androgen receptor to fold into different shapes, which determines which co-activator proteins are recruited and which genes get transcribed — this is the molecular basis of selectivity.
SARMs vs. Anabolic Steroids: Key Differences
Androgen receptor selectivity: Anabolic steroids activate androgen receptors non-selectively across all tissues. SARMs aim for tissue-specific activation — though the degree of selectivity varies significantly by compound.
Oral bioavailability: Most SARMs studied in preclinical settings are orally active. Traditional testosterone-based compounds typically require injection for comparable bioavailability in animal models.
Aromatization: Most SARMs do not aromatize, meaning estrogen-related activity is generally not a factor in SARM-focused research.
Approval status: No SARM has yet received FDA approval for therapeutic use in humans. They remain research compounds studied in preclinical settings and early-phase clinical trials.
Key SARM Compounds Under Research
LGD-4033 (Ligandrol)
LGD-4033, also known as Ligandrol, is one of the most extensively studied non-steroidal SARMs. Originally developed by Ligand Pharmaceuticals and later advanced by Viking Therapeutics, research has focused primarily on its anabolic effects in skeletal muscle and bone tissue. Its high affinity for the androgen receptor and favorable oral bioavailability have made it a frequently referenced compound in SARM literature.
→ View LGD-4033 (Ligandrol) research compound
GW501516 (Cardarine)
GW501516, commonly called Cardarine, is frequently grouped with SARMs but is technically a PPARδ agonist rather than an androgen receptor modulator. Research has centered on its effects on lipid metabolism, fatty acid oxidation, and endurance capacity in preclinical models. Researchers should note that GlaxoSmithKline halted development of GW501516 due to carcinogenicity findings in animal studies — this is documented in the published literature and is critical context for any research protocol.
→ View GW501516 (Cardarine) research compound
SR9009 (Stenabolic)
SR9009 is a synthetic Rev-Erb agonist that targets Rev-Erb proteins, which play a role in circadian rhythm regulation, mitochondrial biogenesis, and lipid and glucose metabolism. Preclinical studies have examined its effects on metabolic activity and exercise endurance in mouse models.
→ View SR9009 (Stenabolic) research compound
RAD-150 (TLB-150)
RAD-150, also designated TLB-150, is a benzoate ester of RAD-140 (Testolone), designed to provide extended release characteristics versus the parent compound. Research interest in RAD-150 has grown as researchers study its pharmacokinetic profile relative to RAD-140.
→ View RAD-150 (TLB-150) research compound
Enclomiphene Citrate
Enclomiphene Citrate is a selective estrogen receptor modulator (SERM) that works by blocking estrogen receptors in the hypothalamus and pituitary, stimulating increased LH and FSH production and thereby stimulating endogenous testosterone production. Research has reached clinical trial stages with published data on its effects in men with secondary hypogonadism.
→ View Enclomiphene Citrate research compound
Non-Hormonal Research Compounds Often Studied Alongside SARMs
Researchers working with SARMs frequently study complementary compounds that operate through non-hormonal mechanisms. Our Complete Guide to Nootropics covers the non-hormonal side of this research space — including Noopept, Bromantane, and 5-AMINO-1MQ.
Current Status of SARM Research
As of the most recent published literature, no SARM has completed Phase III clinical trials or received regulatory approval for therapeutic use. The majority of human data comes from Phase I and Phase II trials, with most published efficacy data from preclinical rodent models. In the United States, most SARMs are classified as unapproved drugs. The FDA has issued multiple warnings about SARMs being marketed for human consumption — they are sold strictly as research compounds for laboratory use.
Sourcing Research-Grade SARMs
For researchers sourcing SARMs for preclinical studies, compound purity and third-party verification are the two most critical factors. Batch-level Certificate of Analysis (COA) documentation from an independent laboratory is the minimum standard for legitimate research-grade material. Chemyo Sarms supplies research-grade SARMs with third-party COA testing for each batch.
- LGD-4033 (Ligandrol)
- GW501516 (Cardarine)
- SR9009 (Stenabolic)
- RAD-150 (TLB-150)
- Enclomiphene Citrate
Frequently Asked Questions About SARMs
Are SARMs legal to buy for research purposes?
In the United States, SARMs are not scheduled controlled substances, meaning they can be legally purchased for legitimate research purposes. They cannot legally be sold for human consumption. Regulatory status varies by country.
How do SARMs differ from prohormones?
Prohormones are precursors that convert to active anabolic hormones in the body. SARMs are not steroid precursors — they act directly on androgen receptors without converting to testosterone or other androgens.
What is the difference between a SARM and a SERM?
SARMs (Selective Androgen Receptor Modulators) act on androgen receptors. SERMs (Selective Estrogen Receptor Modulators) act on estrogen receptors. Enclomiphene citrate is a SERM, not a SARM. Both are selective receptor modulators but they target entirely different receptor systems.
Where can I find published research on SARMs?
PubMed (pubmed.ncbi.nlm.nih.gov) is the primary database for peer-reviewed pharmacological research. Searching compound names alongside terms like “pharmacokinetics” or “preclinical” will surface the most relevant academic literature.
All compounds described on this page are sold strictly for research purposes. They are not intended for human consumption. For educational reference only.