MK2866 – Ostarine

What is Ostarine (MK-2866)?

Ostarine, also known as MK-2866, is a selective androgen receptor modulator (SARM) developed by GTx Inc. for the treatment of muscle wasting and osteoporosis. It is one of the most clinically studied SARMs to date and is widely recognized for its ability to preserve and build lean muscle tissue without harsh side effects.

Unlike traditional anabolic steroids, Ostarine is tissue-selective—it targets skeletal muscle and bone without impacting the prostate, liver, or cardiovascular system. This makes it a leading compound in research studies focused on body recomposition, injury recovery, and age-related muscle loss.

Chemical Properties

How Does MK-2866 Work?

Ostarine binds selectively to androgen receptors in muscle and bone tissue, stimulating anabolic activity while avoiding undesirable effects in reproductive organs. This leads to increased protein synthesis, improved nitrogen retention, and muscle preservation—even in calorie deficits.

Its low androgenic index makes it one of the safest SARMs for research subjects, and it’s frequently used in both cutting and recovery studies due to its joint-healing and anti-catabolic potential.

Potential Benefits Of MK-2866 Ostarine

• Lean Muscle Preservation: May help retain or build muscle during calorie restriction.
• Fat Loss: Promotes recomposition by supporting lean mass while reducing fat stores.
• Joint Support: Reported to aid in joint and tendon recovery in test environments.
• Mild Profile: Minimal suppression and side effects compared to other SARMs.

Clinical Research & Findings

Ostarine has undergone multiple human trials, showing significant improvements in lean body mass and functional strength over placebo. In one 12-week study, elderly participants gained 1.5 kg of muscle without changes to diet or exercise. Its low toxicity and non-methylated structure also make it suitable for extended research cycles and for pairing with other compounds.

MK-2866 Ostarine Dosage Guide

Ostarine is commonly dosed at 10–25mg per day depending on research goals. Its half-life of approximately 24 hours allows for once-daily administration. Research cycles typically last 8–12 weeks.

While it exhibits low suppression at moderate doses, post-cycle therapy (PCT) is recommended for cycles over 10mg/day or longer than 8 weeks.

• Recomposition (Lean Mass + Fat Loss): 20–25mg per day for 8–12 weeks
• Cutting Phase Support: 15–20mg per day for 6–8 weeks
• Joint Recovery: 10–15mg per day for 4–6 weeks

Stacking Ostarine With Other SARMs

“Can MK-2866 be combined with other SARMs?” Absolutely. Ostarine is often used as a foundation in both beginner and advanced stacks, especially for cutting, recovery, and joint support.

Three popular stack partners:

1. Cardarine (GW-501516): Enhances endurance and accelerates fat loss while Ostarine maintains lean tissue.
2. Andarine (S4): For a dry, vascular recomposition effect during cutting phases.
3. Ibutamoren (MK-677): Improves sleep, recovery, and growth hormone support alongside Ostarine’s mild anabolic properties.

FAQs

Is Ostarine legal?

Yes. MK-2866 is legal to purchase for research purposes in Canada and internationally. It is not approved by the FDA for human use.

Does MK-2866 suppress testosterone?

At lower doses, suppression is minimal. However, extended cycles or high dosages may result in mild suppression. A light PCT is recommended post-cycle.

How long is the half-life of Ostarine?

Ostarine has a half-life of approximately 24 hours, allowing for once-daily research administration.

What form does this product come in?

This product is available in powder and liquid form with ≥98% purity, suitable for validated laboratory research applications.

Disclaimer

For laboratory use only. Not for human or veterinary use.

This material is intended strictly for research purposes under controlled laboratory conditions. It is the buyer’s responsibility to ensure legal and ethical use in accordance with institutional, local, and federal guidelines.

Always wear proper safety equipment and follow appropriate handling procedures.