Agonist
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GH SecretagogueOral

MK-677

Also known as: Ibutamoren · L-163191

Orally active non-peptide ghrelin receptor agonist. Produces sustained GH and IGF-1 elevation with a 24-hour duration — unlike injectable GHRPs which require multiple daily doses.

At a glance

Half-life
6 hours
Common route
Oral
Typical dose range
10,000–25,000mcg
Stability (reconstituted)
365days refrigerated

Best timing

Once daily, time-of-day flexible. Pre-bed dosing increases overnight GH but worsens water retention and morning grogginess for some.

Contraindications

  • Active cancer
  • Heart failure (associated with edema-related decompensation in elderly trials)
  • Diabetes (insulin resistance development)
  • Pregnancy
  • Sleep apnea (untreated)

Watch symptoms

  • Water retention and weight gain (often 3–5 lb in first 2 weeks)
  • Increased hunger
  • Fasting glucose elevation
  • Lethargy or grogginess
  • Numbness or tingling (carpal tunnel)

Citations

The primary literature.

  1. 01Two-year treatment with the GH secretagogue MK-677 increases GH and IGF-IPubMed
  2. 02Oral administration of MK-677, a nonpeptide GH secretagogue, reverses diet-induced catabolismPubMed
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