Source comparison
MK-677 IGF-1 LR3 Protocol Growth Factor Research: Comparison
Mechanism Ghrelin receptor agonist → pulsatile GH release → hepatic IGF-1 synthesis Direct IGF-1 receptor agonist with reduced IGFBP binding Systemic upregulation + acute localized signaling Combined approach layers chronic elevation with acute peaks. Theoreti
This comparison does not assign a generated winner or score.
- Mechanism
- Ghrelin receptor agonist → pulsatile GH release → hepatic IGF-1 synthesis
- Direct IGF-1 receptor agonist with reduced IGFBP binding
- Systemic upregulation + acute localized signaling
- Combined approach layers chronic elevation with acute peaks. Theoretically superior but requires precise timing
- Administration
- Oral, once daily, 10–25mg
- Subcutaneous, daily to 3x/week, 20–80mcg
- MK-677 daily + IGF-1 LR3 post-intervention
- MK-677's oral bioavailability simplifies compliance; IGF-1 LR3 requires injection technique training
- Half-Life
- ~24 hours
- 20–30 hours
- N/A
- Extended half-lives allow flexible dosing schedules without loss of receptor occupancy
- Stability
- Stable at room temp 12–24 months (powder)
- Requires 2–8°C storage, 28-day use window post-reconstitution
- Separate storage required
- IGF-1 LR3 cold chain is the protocol's limiting constraint. MK-677 storage is trivial by comparison
- IGF-1 Elevation
- 40–90% above baseline over 2 weeks
- Immediate supraphysiological tissue concentration
- Sustained baseline + acute peaks
- MK-677 provides the foundation; IGF-1 LR3 delivers intervention-specific amplification
- Typical Protocol Length
- 8–12 weeks continuous
- 4–6 weeks pulsed or continuous
- 8–12 weeks MK-677 + 4–6 weeks IGF-1 LR3
- Longer MK-677 use is well-tolerated; IGF-1 LR3 duration limited by desensitization risk