Skip to content

Ipamorelin vs MK-677 (Ibutamoren)

Updated 9 sources

Key differences

  1. 1MK-677 is a daily pill with all-day action; ipamorelin is a short-acting injection given in pulses.
  2. 2MK-677 brings more hunger, water retention and blood-sugar effects; ipamorelin largely spares cortisol and prolactin.
  3. 3Guides pick MK-677 for convenience and ipamorelin for a cleaner side-effect profile.

Side by side

Facts from each record, in the same words as their own pages.
Ipamorelin and MK-677 (Ibutamoren) side by side
IpamorelinMK-677 (Ibutamoren)
Category
  • GH axis
  • GH axis
Evidence
  • Limited human data
  • Some human trials
FDA status
  • Not FDA approvedRegulatory
  • FDA 503A Category 2Regulatory
WADA
  • Prohibited
  • Prohibited
Half-life
  • About 2 hours after IV infusion in healthy men. Subcutaneous half-life has not been published.Clinical study
  • About 4 to 6 hours, measured in beagles; no human plasma half-life in the sources.Reference work
  • About 24 hours, per most guides. That figure tracks how long the effect lasts more than plasma levels.Competitor guide
Routes
  • Subcutaneous injection
  • Oral
FormsNot reported
  • Capsule, Oral solution
Reported doses
  • 100 to 400 mcg (subcutaneous injection)
  • 2 to 25 mg (oral)
  • 0.8 to 3.2 mg/kg (oral)
Most cited frequency
  • Once daily, before bed
  • Once daily
Vial sizes
  • 2 mg, 5 mg, 10 mgCompetitor guide
Not reported
Mixed vial keeps
  • Fridge, 2 to 8 °C.Competitor guide
Not reported
Protocols on file
  • 10
  • 16

Doses shown are what sources report, labelled by origin. Not medical advice.

Read each in full

Sources

9 sources, each checked by date. Record updated Oct 24, 2026. Numbers are restated in our own words and labelled by where they came from.

Clinical study1

  1. Ipamorelin PK-PD (Gobburu 1999)PubMed · checked Oct 23, 2026

Regulatory2

  1. Certain bulk drug substances, safety risksFDA · checked Oct 23, 2026
  2. 503A bulk drug substance categories (May 14, 2026)FDA · checked Oct 23, 2026

Reference work1

  1. IbutamorenWikipedia · checked Oct 24, 2026

Competitor guide4

  1. MK-677PeptidesExplorer · checked Oct 24, 2026
  2. MK-677 (Ibutamoren) protocol guidePathToPeptides · checked Oct 24, 2026
  3. MK-677 (Ibutamoren) dosage guideBodyHackGuide · checked Oct 24, 2026
  4. MK-677PeptideDeck · checked Oct 24, 2026

Community-reported1

  1. Ibutamoren (MK-677): community protocols and reportsPeptide Protocol Wiki, via a competitor guide · checked Oct 24, 2026