If a supplied lot fails agreed specifications, we’ll replace it at no cost or refund its purchase price in full.
Quality test failed? Free replacement or full refund.
Off-spec? Free replacement or full refund.
Reading a Peptide HPLC Trace — A 5-Minute Field Guide for Bench Scientists. Read our briefing →
Reading a peptide HPLC trace — a field guide. Read →
On reading HPLC traces. Read →
Melanocortin receptor agonist · regulated research peptide
Research documentation
Ask sales for the Melanotan II batch COA and the analytical evidence needed to qualify the material for your study. Confirm the available purity and identity records, lot continuity, handling information, and method requirements before ordering.
Overview
Melanotan II (MT-II) is a cyclic heptapeptide that acts as a non-selective melanocortin-receptor agonist, engaging MC1R, MC3R, MC4R and MC5R rather than any single subtype. This broad engagement links its two most-studied research readouts to distinct receptor populations: pigmentation responses trace to MC1R on melanocytes, while central sexual-function effects trace to MC4R in the CNS. Structurally it derives from α-MSH, with a lactam bridge closing Asp5 to Lys10 to lock the backbone into a constrained, high-affinity conformation while conferring resistance to proteolysis. Lyochem supplies Melanotan II as a lyophilized reference standard to a ≥99.0% HPLC purity specification, with release governed by RP-HPLC peak integration and ESI-MS identity confirmation. The mass check verifies the cyclic species at a theoretical 1024.18 Da, 18 Da below the linear precursor owing to the dehydration that forms the lactam — a useful diagnostic that the ring closed as intended. Water and counter-ion content are available on request and listed on the COA when tested. MT-II is tightly controlled across the UK, Australia, Canada and EU markets and prohibited for human consumption in many; it is offered strictly as a research material and not for any use amounting to human administration where such use is barred.
Applications & buyer fit
Other research peptides in this category — Melanotan I, Melanotan II, PT-141, ACE-031, Adipotide / FTPP, EPO, HCG, HMG — ship to research labs studying topics outside the GH / cognitive / immune / mitochondrial / repair / longevity / Khavinson clusters. Each peptide has its own analytical-packet emphasis (e.g. glycoprotein bioassay in IU/mg for HCG; cyclised-form confirmation for oxytocin) noted in the per-product CoA scope.
Academic Laboratories
Universities, medical schools, and government research institutes qualifying a reference standard for a method-development or in vivo workflow.
Every lot has its own batch-specific CoA — HPLC purity and MS identity, plus any analytical scope agreed at quote stage — tied to the exact lot you receive.
Review a representative batch CoA before you order, so you can confirm the packet matches what your method or sponsor audit needs.
Supplied strictly as a research reagent to research institutions — not a finished dosage form and not for human administration. Buyer qualification runs at the inquiry stage.
Specifications
Documentation available on request
Regulatory note
A compliance review is required before any order proceeds. This compound is heavily regulated and carries a human-use ban across multiple jurisdictions, among them the UK, Australia, and several EU markets. We supply it exclusively for legitimate research use, and only to qualified buyers who hold appropriate licensing in their jurisdiction.
Selected literature
Frequently asked questions
Cyclization removes one water molecule, so the cyclic product is 18 Da lighter than its linear precursor; ESI-MS reading the theoretical cyclized mass of about 1024 Da is the primary confirmation that the ring formed. RP-HPLC supplies orthogonal evidence, because the folded cyclic species and the open-chain precursor elute at clearly different retention times. An analyst should look for both a mass consistent with water loss and a single dominant peak matching the cyclic reference position; a peak at the heavier linear mass signals incomplete cyclization and a batch lacking the intended pharmacology.
The uncyclized precursor has markedly lower receptor affinity, so any fraction that failed to close the Lys-to-Asp lactam is effectively inactive material inflating the apparent weight of peptide. For reference-standard use this distorts potency normalization: an assay calibrated against nominal mass will read low if part of that mass is linear species. Reporting the cyclic-to-linear ratio, resolved by the 18 Da mass gap and the RP-HPLC retention difference, lets an analyst assign a meaningful active content to the batch rather than assuming the full weighed amount is the pharmacologically defining cyclic form.
Related peptides