Ghrelin vs Ibutamoren

Head-to-head comparison of Ghrelin (Ghrelin (acylated human ghrelin; endogenous growth hormone secretagogue)) and Ibutamoren (Ibutamoren mesylate (MK-677)) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyGhrelinIbutamoren
CategoryGrowth HormoneGrowth Hormone
Full NameGhrelin (acylated human ghrelin; endogenous growth hormone secretagogue)Ibutamoren mesylate (MK-677)
Molecular Weight3367 DaN/A
Half-Life20-30 minutesabout 24 hours
Amino Acids28N/A
Typical Dose1-3 mcg/kg10-25 mg/day
RouteSubcutaneous/IntravenousOral
Purity≥98%≥98%
Studies Count2000180
Research StatusClinical researchClinical

Ghrelin Benefits

  • increases GH pulses
  • supports appetite and energy intake
  • may support lean mass preservation
  • promotes recovery signaling

Ibutamoren Benefits

  • raises GH/IGF-1
  • increases appetite
  • supports lean mass retention
  • oral non-peptide secretagogue

Ghrelin Dosing

1-3 mcg/kg SC or IV|repeat dosing in short research windows|titrate to GH response in monitored studies

Ibutamoren Dosing

10-25 mg orally once daily|take consistently at the same time each day|monitor fasting glucose and edema in longer studies

Ghrelin Side Effects

  • hunger/nausea
  • transient flushing
  • changes in glucose/insulin

Ibutamoren Side Effects

  • increased appetite
  • water retention/edema
  • somnolence or lethargy

Research Overview

Ghrelin

Ghrelin is the canonical ligand for the growth hormone secretagogue receptor and is used extensively as a reference compound in GH-axis research. Human and animal studies consistently show rapid, dose-dependent GH release after acyl-ghrelin administration.

Ibutamoren

Clinical studies show oral ibutamoren reliably elevates GH and IGF-1 over 24 hours with once-daily dosing. Body composition and appetite effects vary by population, and development has been limited by metabolic side effects.

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Common Stacking Partners

Ibutamoren stacks with:

Resistance trainingHigh-protein diet
ghrelinghsr1asecretagogueghrelin-receptor-agonistgh-secretagogueoral