SARMs (selective androgen receptor modulators) are small, non-steroidal molecules designed to bind the androgen receptor. Peptides are short chains of amino acids that act on many different receptors and pathways. They are different classes of compound with different structures, formats and testing methods. Both are sold by Explicit SARMs for laboratory research only.
By the Explicit SARMs Team. Updated October 23, 2026.
What is a SARM?
A SARM is a synthetic small molecule that binds the androgen receptor with a degree of tissue selectivity. Examples include ostarine (MK-2866), RAD-140 and LGD-4033. SARMs are not steroids, and none has been approved as a drug.
What is a peptide?
A peptide is a short chain of amino acids joined by peptide bonds, usually fewer than about 50 residues. Research peptides include BPC-157, TB-500, ipamorelin and GHK-Cu. Each acts on its own target, so peptides are a broad family rather than a single mechanism.
Where does MK-677 fit?
MK-677 (ibutamoren) is often grouped with SARMs in online stores, but it is neither a SARM nor a peptide. It is a small-molecule ghrelin receptor agonist, a growth hormone secretagogue. Our research article on MK-677 covers it in more detail, and it is available as capsules and a liquid.
How do SARMs and peptides differ in structure?
| SARMs | Peptides | |
|---|---|---|
| Type of molecule | Small synthetic organic molecule | Chain of amino acids |
| Typical molecular weight | Roughly 300-450 | Roughly 300 to several thousand |
| Main target | Androgen receptor | Varies by peptide |
| Common formats | Capsules, liquids | Lyophilized vials, sprays, capsules, gel |
What formats are they sold in?
SARMs are usually supplied as capsules or liquids. Peptides are most often supplied as lyophilized powder in a vial, and some are also offered as sprays, a gel or capsules. Our guide to BPC-157 and TB-500 formats compares these.
How is each class tested?
Both are tested with HPLC for purity and mass spectrometry for identity. For peptides, identity testing confirms the full amino-acid chain by its mass; for SARMs, it confirms the small-molecule structure. At Explicit SARMs, every batch is manufactured in the US, tested twice by our manufacturer, then independently tested by Accumark on our behalf before it ships. See how we test and how to read a COA.
Can SARMs and peptides be combined in one product?
Blends exist within each class. Peptide blends include KLOW and BPC-157 / TB-500. SARM blends include SX3 (MK-2866, S4 and SR9009) and MX3 (RAD-140, YK-11 and LGD-4033).
Are SARMs or peptides approved for human use?
No. The research compounds discussed here are not approved drugs, and we sell them for laboratory and in-vitro research only. We do not provide usage guidance.
Where can I browse both?
See our SARM capsules and research peptides collections.
Why are SARMs and peptides often sold by the same suppliers?
Both are used as reference compounds in receptor and signaling research, and both rely on the same kind of analytical testing. That overlap is why many research suppliers, including us, carry both classes.
Is YK-11 a SARM?
YK-11 is usually listed with SARMs, but its structure is steroidal, unlike most SARMs. It is described in the literature as a partial androgen receptor agonist. Our YK-11 research article covers it in more detail.
Is SR9009 a SARM?
No. SR9009 (stenabolic) is a synthetic Rev-Erb agonist that acts on proteins involved in circadian regulation. It is sold alongside SARMs but works through a different target. See our SR9009 research article.
Are peptides always larger than SARMs?
Not always. Very short peptides such as KPV and GHK-Cu are tripeptides with molecular weights in the same range as some SARMs. The difference is structural: a peptide is built from amino acids, while a SARM is a non-peptide organic molecule.
For laboratory research use only. Not for human consumption. Sold by Explicit SARMs solely as reference material for in-vitro and laboratory research by qualified professionals. Not evaluated by the FDA and not intended to diagnose, treat, cure or prevent any disease.