What is Ostarine (enobosarm, MK-2866)?
The short answer
Ostarine is a lab-made pill that is studied in research on the same system as male hormones.
What it is
Non-steroidal androgen-receptor ligand designed for tissue selectivity.
What people look into
Muscle and exercise
- 6 sources
- Status as of
- How we source
- Ellum doesn't sell peptides.
Get updates on Ostarine (enobosarm, MK-2866)
What it is
- Type
- Selective androgen receptor modulator (SARM), non-steroidal
- Also known as
- enobosarm, mk-2866, gtx-024, ostabolic
- How it works
- Non-steroidal androgen-receptor ligand designed for tissue selectivity.
Regulatory status
Not FDA-approved How we label status
As of October 4, 2026, Ostarine (enobosarm, MK-2866) is not FDA-approved for any use and is not on FDA's 503A bulks list.
- Federal (FDA)
- Not FDA-approved (openFDA: no application); excluded from the dietary supplement definition under 201(ff)(3) (FDA ingredient directory categories 2, 4)
- 503A compounding
- No category; not on 216.23 as of 2026-10-07 (as of October 7, 2026)
- WADA 2026
- S1.2 (named enobosarm (ostarine))
US enforcement actions
2 US enforcement actions since 2023.
Actions by US federal and state agencies whose documents name Ostarine (enobosarm, MK-2866). Each row links to the government's own document.
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US enforcement actions table
| Date | Agency | Action | Document |
|---|---|---|---|
| FDA | Warning letter | FDA document, warning letter, December 12, 2025, on fda.gov | |
| FDA | Warning letter | FDA document, warning letter, June 12, 2023, on fda.gov |
References
Sources as of October 4, 2026
- FDA: www.fda.gov/food/dietary-supplements/information-select-dietary-supplement-ingredients-and-other-substances
- FDA: www.fda.gov/consumers/consumer-updates/fda-warns-use-selective-androgen-receptor-modulators-sarms-among-teens-young-adults
- FDA warning letter, December 12, 2025 (1 of 2)
- FDA warning letter, December 12, 2025 (2 of 2)
- WADA: www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
- eCFR: www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-216/subpart-B/section-216.23