PEPTIDE
Verified ComparisonLast updated: 3 April 2026

IGF-1 LR3 vs MK-677

IGF-1 LR3 is a long-acting IGF-1 analog providing direct growth-factor activity. MK-677 is an oral ghrelin mimetic that stimulates endogenous growth hormone release.

Compound A

IGF-1 LR3

Growth Hormone

Evidence
4.3/ 5
A−

Compound B

MK-677 / Ibutamoren

GH Secretagogue

Evidence
3.9/ 5
B+
Editor's note
IGF-1 LR3 is direct but has systemic effects; MK-677 stimulates endogenous GH.
CriterionIGF-1 LR3MK-677 / Ibutamoren
MechanismDirect IGF-1 analogGhrelin mimetic (GH secretagogue)
RouteSubcutaneous injectionOral
Half-lifeLongShort
Endogenous GH axisSuppressedStimulated
Off-target effectsHigher systemic exposureMore physiologic

Frequently asked questions

MK-677 stimulates endogenous GH; IGF-1 LR3 provides direct systemic exposure.

Want to read the full reviews?

Read IGF-1 LR3 reviewRead MK-677 / Ibutamoren review