# Ibutamoren (MK-677) Capsules

> Oral non-peptide ghrelin-receptor agonist, bottles of 30 capsules

All products are sold strictly for laboratory research use only. Not for human or veterinary use.

- Web page: https://peptidemedixeu.com/en/products/ibutamoren-mk-677/
- Brand: Peptide Medix EU
- Category: [GHRPs & Secretagogues](https://peptidemedixeu.com/en/collections/ghrp-peptides/)
- Purity: ≥98% by HPLC; lot-matched COA available
- CAS number: 159752-10-0
- from €55 (EUR)

## Sizes and prices (EUR)

| Size | Price | SKU |
| --- | --- | --- |
| 12.5 mg · 30 capsules | €55 | IBUTAMOREN-MK-677-12-5-MG-30-CAPSULES |
| 25 mg · 30 capsules | €85 | IBUTAMOREN-MK-677-25-MG-30-CAPSULES |

_Catalog prices at build time; the web page and checkout are authoritative._

## Specifications

- **CAS number:** 159752-10-0
- **Molecular formula:** C27H36N4O5S
- **Molecular weight:** 528.66 g/mol
- **Form:** Oral capsules in a sealed bottle with desiccant
- **Purity:** ≥98% by HPLC; lot-matched COA available
- **Available sizes:** 12.5 mg × 30 capsules, 25 mg × 30 capsules
- **Compound class:** Non-peptide spiropiperidine growth hormone secretagogue
- **Molecular target:** Growth hormone secretagogue receptor 1a (ghrelin receptor)
- **Also known as:** MK-677, MK-0677, L-163,191, ibutamoren mesylate (salt form)
- **Reported half-life:** Approximately 24 hours in published pharmacokinetic studies
- **Research areas:** GH and IGF-1 axis, sleep architecture, body composition, bone mineral density, appetite regulation
- **Storage:** Room temperature in the sealed bottle, protected from light, heat and humidity
- **Reconstitution:** None required — supplied in finished capsule form

## Description

Ibutamoren — known during development as MK-677 and L-163,191 — contains no peptide whatsoever. Merck designed this small spiropiperidine molecule to copy the action of growth hormone-releasing peptides on their receptor (the growth hormone secretagogue receptor) while surviving the stomach and gut. That difference counts: all the other compounds in this department are peptides that digestion would break down, whereas MK-677 was made to be absorbed orally from the start — hence we sell it in capsules and not as a freeze-dried vial.

Chemically, ibutamoren is a spiro-fused piperidine (C27H36N4O5S, 528.66 g/mol) that came from refining earlier peptide-like secretagogues rather than from trimming a peptide. Published pharmacokinetic studies give it a half-life of about 24 hours — the property behind most of its uses: it stimulates the secretagogue receptor continuously, while the peptide GHRPs listed beside it cause short, separate pulses, so the two suit quite different study designs. Research covers the growth hormone/IGF-1 axis, sleep structure, body composition, bone density and appetite. Each bottle holds thirty capsules of either 12.5 mg or 25 mg; keep it closed at room temperature with the desiccant inside.

## Frequently asked questions

### Is MK-677 a peptide?

No. Ibutamoren is a small, non-peptide molecule (a spiropiperidine) made to mimic peptide secretagogues at the ghrelin receptor. Having no peptide backbone, it isn't destroyed by digestion — which is why it comes in capsules rather than as powder for reconstitution.

### Is it independently tested, and can I see a COA?

Yes. For every lot, an outside laboratory measures purity by HPLC and confirms identity by mass spectrometry, and the amount in the capsules is checked against the stated strength. The certificate that matches the lot number on your bottle can be requested.

### What storage do MK-677 capsules need?

Keep the bottle closed at room temperature, desiccant inside, away from light, heat and moisture. Unlike lyophilised peptides it needs neither fridge nor freezer. Avoid humid places such as bathrooms, where capsule shells soften and may stick together.

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All products offered on this website are intended solely for in-vitro laboratory research and development by qualified professionals. They are not drugs, foods, cosmetics or dietary supplements, and are not intended to diagnose, treat, cure or prevent any disease. Products must not be introduced into humans or animals in any manner. By purchasing, you confirm that you are a qualified researcher and accept full responsibility for handling and storage in accordance with applicable laws.

Peptide Medix EU · https://peptidemedixeu.com/en/products/ibutamoren-mk-677/