Comparison

Ipamorelin vs LL-37

Function

While Ipamorelin is investigated for producing moderate, physiologic-like GH pulses useful for studying anabolic, body-composition, and recovery effects with a relatively clean endocrine side-effect profile compared with earlier GHRPs16, LL-37 acts as a broad-spectrum antimicrobial and immunomodulatory peptide involved in host defense and wound repair, but can also promote inflammation and cancer cell proliferation in some contexts5215.

Mechanism

While Ipamorelin works as a third-generation pentapeptide growth hormone secretagogue that selectively agonizes the ghrelin (GHSR-1a) receptor to trigger controlled, GH-specific pituitary release with minimal effects on cortisol or prolactin16269596, LL-37 is a cationic amphipathic 37-amino-acid cathelicidin peptide generated from hCAP18 that disrupts microbial membranes and modulates innate immunity, including chemotaxis, cytokine induction, and NET formation521586.

Length and Sequence

Ipamorelin is 5 amino acids long, whereas LL-37 is longer as it has a length of 37 amino acids. Ipamorelin is made up of a sequence of Aib, Histidine, D-2-Nal, Phenylalanine, Lysine. LL-37 is made up of a sequence of Leucine, Leucine, Glycine, Aspartic acid, Phenylalanine, Phenylalanine, Arginine, Lysine, Serine, Lysine, Glutamic acid, Lysine, Isoleucine, Glycine, Lysine, Glutamic acid, Phenylalanine, Lysine, Arginine, Isoleucine, Valine, Glutamine, Arginine, Isoleucine, Lysine, Aspartic acid, Phenylalanine, Leucine, Arginine, Asparagine, Leucine, Valine, Proline, Arginine, Threonine, Glutamic acid, Serine.

Receptor

Ipamorelin

Ghrelin/growth hormone secretagogue receptor type 1a (GHSR-1a)169596104

LL-37

Functions as a ligand for CXCR2 on neutrophils and other myeloid cells; LL-37 signaling has also been linked to FPR2 and P2X7 in various cell types515

Organism or Origin

Ipamorelin

Fully synthetic peptide ghrelin mimetic16

LL-37

Human cathelicidin antimicrobial peptide generated from the CAP-18 precursor5286

Gene

Ipamorelin

GHSR

LL-37

CAMP

Sources

16Ipamorelin peptide: A gentle pulse, but is it strong enough?, https://oathpeptides.com/2025/11/05/ipamorelin-peptide-a-gentle-pulse-but-is-it-strong-enough/
96Growth Hormone Secretagogue Receptor - ScienceDirect.com, https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/growth-hormone-secretagogue-receptor
52Cathelicidin LL-37: A new important molecule in the ... - PMC - NIH, https://pmc.ncbi.nlm.nih.gov/articles/PMC7388365/
86Cathelicidin antimicrobial peptide - Wikipedia, https://en.wikipedia.org/wiki/Cathelicidin_antimicrobial_peptide