Ostarine (MK-2866, enobosarm) — Research Literature Summary

⚠ No validated human dose. This compound is not FDA-approved and has no peer-reviewed human dose-finding trials. The figures below are research conventions extrapolated from preclinical (animal/in‑vitro) and community sources — not validated clinical dosing. Treat them as study references only. Research use only; not medical advice.

Class: SARM • Page type: research-literature reference • Updated 2026-04-23

Regulatory notice — research reference only

Ostarine (MK-2866, enobosarm) is an investigational SARM. It has not received FDA approval for any indication. The U.S. FDA and DOJ have explicitly enforced against sale of SARMs for human consumption. This page summarizes published clinical research only.

Published research summary

Enobosarm is the most clinically studied SARM. It has been evaluated in Phase II and Phase III trials by GTx, Inc. for muscle wasting in cancer cachexia (POWER trials) and stress urinary incontinence, and more recently by Veru Inc. for breast cancer.
POWER 1 and POWER 2 (Phase III, ~650 NSCLC patients each, 3 mg/day oral for ~4 months) showed improvement in lean body mass versus placebo but did not meet the co-primary stair-climb endpoint required for regulatory approval.
HPT-axis suppression has been observed at doses >= 1 mg/day; long-term safety data are limited to trial durations.
Ostarine is prohibited at all times on the WADA Prohibited List (S1.2).

Why this page does not publish a consumer “cycle” schedule

Published research used fixed doses (1-3 mg/day) for defined trial durations. Consumer 'cycle' or 'PCT' protocols are not reflected in the peer-reviewed record.

Peer-reviewed citations

Consulting a healthcare provider: This page is a reference for published research. If you are considering any health decision, consult a licensed healthcare provider. Path to Peptides does not provide medical advice.

⚠ Before any use: human safety data is limited or absent for many of these compounds. Consult a licensed healthcare provider first — especially if you are pregnant or nursing, have a medical condition, or take other medications.

How do you take Ostarine (MK-2866)?▼

What are the storage requirements for Ostarine (MK-2866)?▼

Store capsules at room temperature in a cool, dry place. Keep tightly sealed, away from moisture and direct light.

Frequently Asked Questions

What is the standard Ostarine (MK-2866) dosing protocol?▼

There is no validated human dose for this compound; the following is a commonly cited research convention, not a validated protocol. The standard Ostarine (MK-2866) research protocol uses 10mg administered morning on protocol days. Weekly Total: 7 capsules (70mg) • Cycle Duration: 8 weeks on, 4 weeks off

How do you take Ostarine (MK-2866)?▼

Ostarine (MK-2866) is an oral compound supplied as capsules. No reconstitution is required. Swallow the capsule with water at the same time each day.

What are the storage requirements for Ostarine (MK-2866)?▼

Store capsules at room temperature in a cool, dry place. Keep tightly sealed, away from moisture and direct light.