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FDA Category 2 · restricted from compounding

This compound is on the FDA’s interim Section 503A Category 2 bulks list and cannot be legally compounded by US pharmacies. An HHS announcement in February 2026 signaled intent to restore several peptides to Category 1, but no Federal Register action has been published. Check the FDA PCAC schedule for updates.

Read the full regulatory context
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MK-677 (Ibutamoren)

Ibutamoren · MK-0677

Once-daily oral ghrelin-receptor agonist that raises GH/IGF-1; Phase 3 Alzheimer's trial failed and frailty program was halted.

◆ Editorial note

Oral non-peptide small molecule (spiropiperidine).

§ 01   Overview

Overview

Once-daily oral ghrelin-receptor agonist that raises GH/IGF-1; Phase 3 Alzheimer's trial failed and frailty program was halted.

Phase 3 Alzheimer's negative; frailty program halted. No approved indication.

§ 02   Mechanism

Mechanism of action

MK-677 is a non-peptide orally active GHS-R1a agonist. It produces sustained GH/IGF-1 elevation with a single daily dose by mimicking ghrelin at the pituitary.

  • 01Convenience of oral daily dosing
  • 02Sustained IGF-1 elevation
  • 03Popularized in bodybuilding communities

§ 03   Dosing

Dosing protocol

Standard Protocol

Dose Range
10 – 25 mg daily (off-label)
Route
Oral
Timing
Before bed
Frequency
Daily
Cycle
8–12 weeks

§ 04   Evidence

Evidence & research

Clinical

Phase 3 Alzheimer's negative; frailty program halted. No approved indication.

FDA Status

Not FDA-approved.

§ 06   News

In the news

6 articles from the last 12 months · updates hourly

§ 07   Sourcing

Sourcing & supply

Regulatory status

Restricted from compounding

Placed on the FDA's 503A Category 2 list and cannot be lawfully compounded in the US. No brand pharmacy alternative exists. US buyers encounter only research-use-only (RUO) channels, which the FDA's Intended Use Doctrine treats as unapproved drug sales.

Research-use-only · 3

Research-use-only

Swiss Chems

Established SARMs/peptide vendor. FDA warning letter Dec 2024 for GLP-1s. Weaker peptide QC than SARMs QC.

Third-Party Testing1 flag on record
Visit
Research-use-only

Limitless Life Nootropics

'Only BBB-accredited peptide company' (since 2020). Claims three-lab third-party testing. Broad catalog.

BBB Accredited +1
Visit
Research-use-only

Core Peptides

Broad catalog, widest payment range. Mid-credibility: Knoji 2.5/5 and one scam-impersonation report.

Third-Party Testing1 flag on record
Visit

Listings are informational, not endorsement. Verify credentials and flags against FDA and PCAB databases before purchasing. Full directory & how to verify →

§ 09   Safety

Safety & side effects

Side effects

  • 01Increased appetite and water retention
  • 02Insulin resistance over time
  • 03Lethargy in some users

Contraindications

None specified.

§ 10   Questions

MK-677 (Ibutamoren) FAQ

What is MK-677 (Ibutamoren)?
Once-daily oral ghrelin-receptor agonist that raises GH/IGF-1; Phase 3 Alzheimer's trial failed and frailty program was halted. MK-677 is a non-peptide orally active GHS-R1a agonist. It produces sustained GH/IGF-1 elevation with a single daily dose by mimicking ghrelin at the pituitary.
What is MK-677 (Ibutamoren) used for?
Reported uses include convenience of oral daily dosing, sustained igf-1 elevation, and popularized in bodybuilding communities. Evidence strength is rated Clinical — see the evidence section for detail.
How is MK-677 (Ibutamoren) dosed?
Commonly referenced dosing is 10 – 25 mg daily (off-label), administered Oral. This is educational reference only; consult a licensed clinician before use.
What are the side effects of MK-677 (Ibutamoren)?
Commonly reported side effects include increased appetite and water retention, insulin resistance over time, and lethargy in some users. This list is not exhaustive.
Is MK-677 (Ibutamoren) legal?
Placed on the FDA's 503A Category 2 list and cannot be lawfully compounded in the US. No brand pharmacy alternative exists. US buyers encounter only research-use-only (RUO) channels, which the FDA's Intended Use Doctrine treats as unapproved drug sales. FDA status: Not FDA-approved..

§ 11   References

Selected references

  1. 01

    Nass — frailty RCT

    PMID: 18981485

  2. 02

    Murphy — pharmacology

    PMID: 11238496

This site is for educational and research purposes only. It does not constitute medical advice. Always consult a qualified healthcare provider before using any peptide or supplement.