Source comparison
IGF-1 LR3 vs MK-677: Full Comparison
Before selecting a compound for your research protocol, understand that these two agents occupy entirely different pharmacological categories. The table below distills the critical distinctions: Mechanism Direct IGF-1 receptor agonist; bypasses IGFBPs Ghrelin
This comparison does not assign a generated winner or score.
- Before selecting a compound for your research protocol, understand that these two agents occupy entirely different pharmacological categories. The table below distills the critical distinctions:
- Mechanism
- Direct IGF-1 receptor agonist; bypasses IGFBPs
- Ghrelin mimetic; stimulates endogenous GH secretion
- IGF-1 LR3 delivers supraphysiological receptor activation; MK-677 works within physiological limits
- Administration Route
- Subcutaneous injection (reconstituted peptide)
- Oral (capsule or powder)
- MK-677's oral bioavailability eliminates injection-related variables
- Half-Life
- 20–30 hours (plasma); 24–36 hours (tissue)
- 4–6 hours (drug); 24 hours (GH elevation)
- IGF-1 LR3's extended half-life allows once-daily dosing with sustained receptor occupancy
- Dosing Range (Research)
- 20–100 mcg/day subcutaneous
- 10–25 mg/day oral
- IGF-1 LR3 doses are 1000× lower by mass but produce more direct anabolic signaling
- Storage Requirements
- Lyophilized: −20°C; Reconstituted: 2–8°C, use within 14 days
- Room temperature stable for 12–24 months
- IGF-1 LR3 requires cold-chain logistics; MK-677 does not
- Dependency on Endogenous GH
- None—works independently of pituitary function
- Complete—requires intact hypothalamic-pituitary axis
- IGF-1 LR3 remains effective in models with suppressed GH; MK-677 does not