Understand the source comparison
IGF-1 LR3 Alternatives 2026 Best: Peptide Comparison
This table compares the primary IGF-1 LR3 alternatives based on mechanism, half-life, dosing frequency, and research application suitability. Use this to match peptide characteristics to your specific protocol requirements. MK-677 (Ibutamoren) Ghrelin receptor
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This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- This table compares the primary IGF-1 LR3 alternatives based on mechanism, half-life, dosing frequency, and research application suitability. Use this to match peptide characteristics to your specific protocol requirements.
- MK-677 (Ibutamoren)
- Ghrelin receptor agonist; stimulates pulsatile GH release
- ~24 hours
- 10–25 mg once daily (oral)
- Chronic GH elevation studies, metabolic research, anabolic protocols
- Best oral bioavailability; most convenient dosing; excellent for long-term studies requiring stable GH stimulation
- Hexarelin
- GHRP; binds GHSR-1a and CD36 receptors
- ~70 minutes
- 100–200 mcg/kg 2–3× daily (SC)
- Cardioprotective studies, acute GH pulse research
- Strongest GH release per dose; cardioprotective via CD36; requires multiple daily injections
- CJC-1295 + Ipamorelin
- GHRH analog + selective ghrelin agonist
- 6–8 days (CJC-DAC) / ~2 hours (Ipamorelin)
- 100–300 mcg CJC weekly + 200–300 mcg Ipamorelin 2–3× daily
- Synergistic GH/IGF-1 studies, body composition research
- Most physiologically refined combination; synergistic effect 2.5× either alone; ideal for multi-week protocols
- GHRP-2
- Growth hormone-releasing peptide; GHSR-1a agonist
- ~60–90 minutes
- 100–300 mcg 2–3× daily (SC)
- Metabolic studies avoiding cortisol/prolactin confounds
- Cleaner selectivity than GHRP-6; no cortisol spike; requires frequent dosing like Hexarelin
- Tesamorelin
- GHRH analog with enhanced receptor affinity
- 26–38 minutes
- 1–2 mg daily (SC)
- Visceral fat reduction, lipodystrophy models
- FDA-approved clinical peptide; selective lipolytic action; minimal diabetogenic effect vs GH