For laboratory research use only. Not for human consumption. Sold by Explicit SARMs as reference material for laboratory research use only by qualified professionals.
Key facts: MK-677 (Ibutamoren) Capsules
- Contents: 90 capsules per bottle, 10mg per capsule
- Price: $80.00 as of November 2026
For laboratory research use only.
MK-677 is ibutamoren, Merck’s compound L-163,191 (also written MK-0677). Each bottle holds 90 capsules at 10mg per capsule, made in the US.
What MK-677 is, and isn’t
MK-677 is sold alongside SARMs and often called one. It isn’t. It has no androgen receptor activity. It’s a small nonpeptide agonist of the growth hormone secretagogue receptor, GHS-R1a, the receptor later shown to bind ghrelin (Howard et al., Science 1996, PMID 8688086; Kojima et al., Nature 1999, PMID 10604470).
Chemistry
The free base is CAS 159634-47-6, C27H36N4O5S, MW 528.7. Most research material and most of the clinical literature use the mesylate salt: CAS 159752-10-0, C28H40N4O8S2, MW 624.8. That difference of about 96 matters when you calculate molar concentrations, so check which form your COA reports.
What the literature reports
Patchett et al. (PNAS 1995, PMID 7624358) described the compound’s design and its GH-releasing activity in rat pituitary cells (EC50 1.3 nM). Merck’s beagle work showed GH elevated for up to six hours after a single gavage administration, followed by a rise in IGF-1 (Jacks et al., Endocrinology 1996, PMID 8940347). Later clinical studies reported changes in GH, IGF-1 and fasting glucose and reduced insulin sensitivity (Chapman et al. 1996, PMID 8954023; Nass et al., Ann Intern Med 2008, PMID 18981485). Trials by Adunsky (2011, PMID 21067829) and Sevigny (2008, PMID 19015485) did not show clinical benefit, and the compound has never been approved.
For the full write-up, read our MK-677 (Ibutamoren) Research Review. Looking for MK-777 (acetamoren)? It is a separate compound: MK-777 (acetamoren) capsules. Prefer a liquid? See MK-677 Liquid.
Specifications
- Compound: ibutamoren (MK-677, MK-0677, L-163,191)
- CAS: 159634-47-6 (free base); 159752-10-0 (mesylate)
- MW: 528.7 (free base); 624.8 (mesylate)
- Target: GHS-R1a (ghrelin receptor) agonist
- Format: 90 capsules, 10mg per capsule
- Not the same compound as: MK-777 (acetamoren)
- WADA: named in S2.2.4, prohibited at all times
How we source and test it
MK-677 is made by US domestic manufacturing partners.
FAQ
Is MK-677 a SARM?
No. It’s a ghrelin-receptor (GHS-R1a) agonist with no androgen receptor activity.
How much do MK-677 capsules cost, and where can I buy them?
As of November 2026, MK-677 (ibutamoren) capsules from Explicit SARMs cost $80 for a bottle of 90 capsules at 10mg each, and you can order directly on this page. US orders of $100 or more ship free, and orders placed before 2 PM ET, Monday to Friday, ship the same day. Sold for laboratory research use only.
Is MK-677 a peptide?
No. It’s a small nonpeptide molecule.
Free base or mesylate?
Most of the clinical literature used ibutamoren mesylate. The COA states which form was tested.
Capsules or liquid?
It’s the same compound. Capsules give a fixed 10mg per unit; the liquid suits protocols that need volumetric measurement. See MK-677 Liquid.
Is it for human use?
No. It’s sold only as reference material for laboratory research.
For laboratory research use only. Not for human consumption.
Who tests MK-677?
No COA is published for this product yet. We are waiting for the next updated batch and will send it to Accumark Labs, an independent third-party lab, for a COA when it arrives.
What payment methods does Explicit SARMs accept?
We accept debit and credit cards, Zelle, Cash App, ACH bank transfer, and cryptocurrency.
Does Explicit SARMs ship worldwide?
We ship to the international destinations shown at checkout. Buyers are responsible for their destination country’s import rules.
Sizes and prices
| Product | Size / format | Price |
|---|---|---|
| MK-677 (Ibutamoren) Capsules | 10mg per capsule | $80.00 |
| MK-677 Liquid | 30mg/mL | $80.00 |
Prices as of November 2026.
