Source comparison
MK-677 Pharmacokinetics: Oral Secretagogue vs Injectable GH Comparison
Route of Administration Oral (capsule/liquid) Subcutaneous injection MK-677's oral delivery eliminates injection site reactions and allows discreet dosing without reconstitution Bioavailability 60–70% oral absorption ~75% subcutaneous ~50% subcutaneous (degrad
This comparison does not assign a generated winner or score.
- Route of Administration
- Oral (capsule/liquid)
- Subcutaneous injection
- MK-677's oral delivery eliminates injection site reactions and allows discreet dosing without reconstitution
- Bioavailability
- 60–70% oral absorption
- ~75% subcutaneous
- ~50% subcutaneous (degrades rapidly)
- MK-677 achieves therapeutic plasma levels without injection. Peptides require subcutaneous delivery
- Mechanism of Action
- GHSR-1a agonist (amplifies endogenous GH pulses)
- Direct GH replacement (suppresses endogenous secretion)
- GHSR agonist (pulsatile GH release, short-acting)
- MK-677 preserves pituitary function. Exogenous GH shuts down natural production
- Dosing Frequency
- Once daily (24-hour IGF-1 elevation)
- 1–2x daily (mimics pulsatile secretion)
- 2–3x daily (2-hour half-life, rapid clearance)
- MK-677's extended pharmacodynamic effect allows single daily dosing without IGF-1 troughs
- Half-Life
- 4–6 hours (compound); 24 hours (IGF-1 response)
- 2–4 hours (requires split dosing for stability)
- 20–30 minutes (necessitates multiple daily injections)
- MK-677's sustained IGF-1 elevation outlasts its plasma half-life. Peptides clear too fast for once-daily protocols
- IGF-1 Elevation
- 46–84% above baseline (sustained for 24 hours)
- 100–300% above baseline (dose-dependent, pulsatile)
- 30–50% transient elevation (returns to baseline within 4 hours)
- MK-677 produces moderate, consistent IGF-1 levels. Exogenous GH creates supraphysiological spikes
- Storage Requirements
- Room temperature (stable in solid form for years)
- Refrigerated (2–8°C); reconstituted vials expire in 28 days
- Refrigerated; reconstituted peptides degrade within 7–14 days
- MK-677 eliminates cold-chain logistics. Peptides and GH require refrigeration throughout handling