Comparison

Melanotan I vs Tesamorelin

Function

While Melanotan I is approved in some regions for prevention of phototoxicity in erythropoietic protoporphyria and is studied as a skin-darkening, photoprotective peptide3444, Tesamorelin is FDA-approved to reduce excess visceral adipose tissue in HIV-associated lipodystrophy and is studied for broader body-composition, NAFLD, and cognitive effects via GH/IGF-1 axis modulation1893.

Mechanism

While Melanotan I works as a linear 13-amino-acid analog of α-MSH (afamelanotide) that selectively activates MC1R on melanocytes, increasing eumelanin synthesis and providing photoprotection3444, Tesamorelin is a full-length 44-amino-acid GHRH analog with an N-terminal trans-3-hexenoic acid modification that binds GHRHR, activating cAMP/PKA signaling to increase endogenous GH and IGF-1, with improved stability versus native GHRH182893102.

Length and Sequence

Melanotan I is 13 amino acids long, whereas Tesamorelin is longer as it has a length of 44 amino acids. Melanotan I is made up of a sequence of Serine, Tyrosine, Serine, Nle, Glutamic acid, Histidine, Phenylalanine, Arginine, Tryptophan, Glycine, Lysine, Proline, Valine. Tesamorelin is made up of a sequence of Tyrosine, Alanine, Aspartic acid, Alanine, Isoleucine, Phenylalanine, Threonine, Asparagine, Serine, Tyrosine, Arginine, Lysine, Valine, Leucine, Glycine, Glutamine, Leucine, Serine, Alanine, Arginine, Lysine, Leucine, Leucine, Glutamine, Aspartic acid, Isoleucine, Methionine, Serine, Arginine, Glutamine, Glutamine, Glycine, Glutamic acid, Serine, Asparagine, Glutamine, Glutamic acid, Arginine, Glycine, Alanine, Arginine, Alanine, Arginine, Leucine.

Receptor

Melanotan I

Melanocortin-1 receptor (MC1R) 344481

Tesamorelin

Growth hormone–releasing hormone receptor (GHRHR) 9394103

Organism or Origin

Melanotan I

Synthetic analog of human α-MSH derived from POMC34448190

Tesamorelin

Synthetic analog of human hypothalamic GHRH1893

Gene

Melanotan I

POMC

Tesamorelin

GHRH

Related articles

No related articles are linked to these peptides yet.

Sources

34Melanotan I (Afamelanotide): Research Profile - PeptideJournal, https://www.peptidejournal.org/peptides/melanotan-i-research-profile
44Melanotan I: properties, applications and references, https://www.benchchem.com/zh/product/b1666627
81Proopiomelanocortin (POMC), the ACTH/melanocortin precursor, is ..., https://pmc.ncbi.nlm.nih.gov/articles/PMC2253185/
90alpha-Melanocyte stimulating hormone: production and degradation, https://pmc.ncbi.nlm.nih.gov/articles/PMC3936413/
18Tesamorelin: Benefits, Dosing & Where to Buy (2026) - Peptides, https://thepeptidecatalog.com/peptides/tesamorelin
28The Ultimate Guide to Tesamorelin | Las Vegas | Sky Health, https://www.skyhealthnv.com/tesamorelin
93Tesamorelin - FDA-Approved GHRH Analog Guide - PeptideMark, https://www.peptidemark.com/peptides/tesamorelin
94Growth-hormone-releasing hormone receptor - Wikipedia, https://en.wikipedia.org/wiki/Growth-hormone-releasing_hormone_receptor
102Tesamorelin: Molecular Characterization and Metabolic Research, https://biotechpeptides.com/2026/03/25/tesamorelin-molecular-characterization-growth-hormone-axis-modulation-and-metabolic-research/
103Growth-hormone-releasing hormone receptor - Wikipedia, https://en.wikipedia.org/wiki/Growth_hormone_releasing_hormone_receptor