MT-1 (Melanotan 1) 10mg

Melanotan I, also called MT-1 and afamelanotide, is [Nle4, D-Phe7]-alpha-MSH: the full 13-residue sequence of alpha-melanocyte-stimulating hormone with two substitutions, kept linear. This listing is a sealed vial holding 10 mg of the peptide as freeze-dried powder, acetylated at the N-terminus and amidated at the C-terminus. Research on it runs from 1980s structure-activity work on alpha-MSH analogues through early clinical studies of skin pigmentation to two randomised trials of an implant formulation in erythropoietic protoporphyria.

Specifications

Melanotan I is not a milder melanotan II

The two names suggest two strengths of one product, but they are different molecules. Melanotan I keeps the whole backbone of alpha-MSH, Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2, with norleucine at position 4 in place of methionine and D-phenylalanine at position 7. Swapping out methionine removes the oxidation-prone thioether that the native hormone carries. Melanotan II is a seven-residue fragment closed into a ring by a lactam bridge.

The masses are far apart: 1646.9 Da for melanotan I against 1024.2 Da for melanotan II, so the LC-MS identity result on the certificate tells them apart at a glance. From the theoretical mass, 10 mg of melanotan I is about 6.1 µmol, slightly less after the water content the certificate reports. The melanotan 1 vs melanotan 2 guide compares the two receptor by receptor.

What the research covers

A superpotent linear analogue

Alpha-MSH is a 13-residue peptide, Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2¹. Structure-activity work in the 1980s produced analogues far more potent than the hormone, and in 1989 Al-Obeidi and colleagues named Ac-[Nle4,D-Phe7]-alpha-MSH, the compound now called melanotan I or afamelanotide, as one of two superpotent analogues their new designs started from¹. Those designs were cyclic lactam fragments, and their potency was measured against alpha-MSH in frog and lizard skin bioassays, the standard tests of melanotropic activity at the time¹. Melanotan I therefore came first; the cyclic peptides that led to melanotan II were designed from what it and its relatives had shown about the hormone¹.

A 2006 review by Hadley and Dorr described the melanocortin analogues from this work as superpotent, prolonged acting and resistant to enzymatic breakdown². Two were patented and moved into clinical testing: melanotan I, the linear peptide, and melanotan II, a truncated cyclic one².

Clinical development

According to Hadley and Dorr, melanotan I was tested clinically in studies of skin tanning, while melanotan II went toward the diagnosis and treatment of male erectile dysfunction². The review abstract gives no results for the tanning studies.

The largest controlled human data in these references concern a different use. Langendonk and colleagues ran two multicentre, randomised, double-blind, placebo-controlled trials of afamelanotide implants in erythropoietic protoporphyria, a photodermatosis in which light exposure causes acute pain³. The European trial enrolled 74 patients and the US trial 94; over study periods of 180 and 270 days they recorded the type and duration of sun exposure, the number and severity of phototoxic reactions, adverse events and quality of life, with photoprovocation testing in a US subgroup³. The primary end point was the number of hours of direct sunlight without pain. In the US study the median after six months was 69.4 hours in the afamelanotide group against 40.8 hours with placebo (P=0.04)³. The trial material was a solid implant, a different article from freeze-dried powder in a vial.

What is not established

The evidence in these references is narrow. Potency comes from amphibian and reptile skin assays¹, the controlled human data from two implant trials in one rare disease³, and the tanning work is mentioned in a review without figures². None of the cited abstracts measures receptor selectivity; the melanotan guide sets out what is known about it, along with afamelanotide’s regulatory history. None of the studies used research-grade powder or PrymaLab material.

The Melanotan 1 vs Melanotan 2 guide covers the literature in more depth.

How each lot is tested

Every lot is tested in PrymaLab’s own laboratory in Ashland, Kentucky before release: RP-HPLC for purity, LC-MS for identity, Karl Fischer titration for water, LAL for endotoxin and USP <71> for sterility. The results for the lot now shipping are in the certificate panel on this page, and the certificate number, key and QR code can be checked on the verify page. These are in-house results from PrymaLab Analytical, not an independent test, and the lab is not accredited to ISO 17025. The third-party testing guarantee on this page still applies: if any independent laboratory finds the wrong compound, or less than the stated purity or amount, the order is refunded and the cost of the test is reimbursed.

Frequently asked questions

References

1. Al-Obeidi F, Castrucci AM, Hadley ME, et al. Potent and prolonged acting cyclic lactam analogues of alpha-melanotropin: design based on molecular dynamics. J Med Chem. 1989;32(12):2555-61. DOI · PubMed
2. Hadley ME, Dorr RT. Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization. Peptides. 2006;27(4):921-30. DOI · PubMed
3. Langendonk JG, Balwani M, Anderson KE, et al. Afamelanotide for Erythropoietic Protoporphyria. N Engl J Med. 2015;373(1):48-59. DOI · PubMed