MK-677 vs L-692,429

Head-to-head comparison of MK-677 (Ibutamoren Mesylate (MK-677)) and L-692,429 (L-692,429) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyMK-677L-692,429
CategoryGrowth HormoneGrowth Hormone
Full NameIbutamoren Mesylate (MK-677)L-692,429
Molecular Weight528.662 g/molN/A
Half-Life~24 hoursunknown / study-dependent
Amino AcidsNon-peptide compoundN/A
Typical Dose0.03-0.1 mg/kg
RouteOral
Purity>99%≥98%
Studies Count12030
Research StatusActive ResearchPre-clinical

MK-677 Benefits

  • Oral GH secretagogue, 24-hour GH elevation, increases IGF-1, improves sleep quality, increases lean mass, does not suppress natural GH

L-692,429 Benefits

  • potent GHSR agonism
  • oral bioactivity in models
  • validates ghrelin pathway
  • useful research probe

MK-677 Dosing

10-25 mg orally once daily before bedtime. 25 mg is the most studied dose. Can be used long-term without cycling.

L-692,429 Dosing

0.03-0.1 mg/kg in early studies|single oral or short-course research dosing|serial GH sampling recommended

MK-677 Side Effects

  • Increased appetite, mild water retention, drowsiness, transient numbness, mild increase in fasting blood glucose with long-term use.

L-692,429 Side Effects

  • increased appetite
  • glucose intolerance
  • transient prolactin changes

Research Overview

MK-677

A landmark 2-year study in elderly adults demonstrated significant increases in lean mass, GH pulsatility, and IGF-1 to youthful ranges. Selectively agonizes GHS-R1a without increasing cortisol or prolactin.

L-692,429

L-692,429 was important in early GH secretagogue research because it showed that nonpeptide molecules could trigger robust GH release. It remains a classic tool compound for studying receptor-mediated GH pulsatility and appetite signaling.

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Common Stacking Partners

MK-677 stacks with:

CJC-1295IpamorelinRAD-140

L-692,429 stacks with:

Receptor assaysEndocrine studies
growth-hormone-secretagogueoralghrelin-mimeticIGF-1muscle-growthsleeptool-compoundgh-secretagogueghrelin-pathway