Ostarine (MK-2866)
The mildest and most-studied selective androgen receptor modulator, known clinically as enobosarm (MK-2866). It was investigated as a treatment for muscle wasting.
- Half-life
- 1.0 d
- Out of system
- ~5 days
- Route
- Oral
- Level
- Intermediate
Daily dosing holds steady levels. After the last dose, roughly 97% has cleared in ~5 days (five half-lives) — the window that matters for washouts, bloodwork and surgery.
What Ostarine (MK-2866) is used for
- Modest gains in lean mass and strength with a milder profile than most SARMs
- Studied clinically for preserving muscle during wasting and calorie deficits
How it's typically used
Reported research and user ranges cluster around 20 mg daily for 8-12 weeks.
What to watch for
- Still suppresses natural testosterone (HPTA) at higher doses, so a PCT may be needed
- Products are frequently mislabeled or underdosed since there is no quality control
- Not approved for human use; an unapproved research chemical banned in sport by WADA
About SARMs
- What they are
- Selective androgen receptor modulators — oral compounds designed to hit muscle and bone androgen receptors while sparing prostate and skin. None is an approved medicine anywhere.
- How they're run
- Taken orally once a day, typically in 8–12 week blocks.
- What to watch
- The "non-suppressive" reputation is marketing: most suppress natural testosterone, and several are liver-toxic. Independent testing repeatedly finds products containing something other than the label. Bloodwork before and after is the minimum.
Full guide
Ostarine (MK-2866): A Tracking Guide for the Most-Studied SARM
A neutral, harm-reduction look at ostarine, why it is the mildest of the SARMs, and what to monitor given it still suppresses natural hormones.
Other sarms
Peptid AI is an educational and self-tracking tool — not a medical service, and not a vendor. Nothing here is medical advice, a prescription, or an endorsement. Doses reflect what is commonly reported in research literature; they are not recommendations. Many compounds listed are experimental, not approved for human use, and/or controlled substances that are illegal to possess without a prescription in many countries. Always consult a qualified physician before starting, changing, or stopping any protocol.