Melanotan II lab report: what to check on a Melanotan II COA

Melanotan II is a small peptide with a ring in it: seven amino acids, six of which close into a loop. The ring, an unusual first amino acid and one amino acid in its mirror image (D) form each give its lab report something specific to check. This guide covers what a Melanotan II certificate of analysis (COA) should show and walks through our own report. For the basics of any report, see How to read a peptide lab report.

What Melanotan II is, chemically

Our product page writes it as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. Read from left to right: an acetyl group (Ac) on norleucine (Nle), then aspartic acid, histidine, phenylalanine in its D form, arginine, tryptophan and lysine, with an amide (NH₂) at the end. The square brackets mark the ring: the side chains of aspartic acid and lysine are joined by a bond, which closes those six amino acids into a loop.

Norleucine is an unnatural amino acid. It has the same formula as leucine, with a straight side chain, and no sulfur atom, which matters for oxidation below.

Purity: the near copies to look for

Purity comes from HPLC: the sample runs through a column, a detector at 214 nm draws a peak for each component, and purity is the main peak’s area as a share of the area of every peak. For a ring peptide like this one, three near copies are worth knowing:

• The open chain, where the ring never closed. It still holds the water molecule that closing the ring releases, so its mass differs from the ring’s.
• The other mirror form. A chain made with phenylalanine in its usual L form instead of the D form has exactly the same mass, so mass spec can’t tell the two apart. It shows only on the HPLC trace, as a separate peak close to the main one, when the method separates them.
• An oxidized form. Melanotan II has no methionine, the amino acid that most often picks up oxygen, but tryptophan can too.

Our report used reversed phase HPLC on a C18 column with a diode array detector at 214 nm. Its chromatogram shows one tall peak, labeled with the compound’s name, a little after 10 minutes, and a small mark in the first two minutes, where the solvent itself usually shows up. The purity is 99.823%, against Kovera’s standard of more than 98%.

Identity: confirmed by mass spec

Mass spectrometry confirms the main peak is Melanotan II by weighing it. The report should state that the measured mass matches the compound named on it. The open chain has a different mass, so it would not pass as Melanotan II.

Kovera lists identity as Identity Confirmation (LC-MS) and prints the result as the compound’s name, with a check mark, rather than the measured signals. On our report it reads Melanotan-2, the same name with the numeral written as a digit.

A similar name

Melanotan I is a different peptide altogether: a straight chain of 13 amino acids with no ring. Despite the similar name, it has its own mass and its own report.

Content: more than the label

Content is the milligrams of Melanotan II the lab measured in the tested vial, not the weight of the powder, which also holds a little water and salts. Our 10mg report found 11.68 mg, about 17% more than the label. Filling a few milligrams of powder is never exact, and like every content result this one describes the vial that was tested; other vials can land a little above or below. For more, see Purity vs content.

Our Melanotan II report

Our Melanotan II 10mg is listed with a report from Kovera Labs, report KVR-2026-3CB15D, certified September 7, 2026. Its sample information shows batch 0001, a lyophilized powder with a labeled quantity of 10 mg. The results: purity 99.823% (standard: more than 98%), net content 11.68 mg (standard: about 10mg), identity confirmed by LC-MS, and an endotoxin screen marked PASS against a limit of 0.5 EU/mL or less. The client name is covered on our copy.

Like every report, it covers the sample that was tested, and the product page says so when the current lot isn’t confirmed as that sample.

Checking a Melanotan II report, step by step

1. The sample: Melanotan II (also written Melanotan-2), the batch and a labeled amount of 10 mg.
2. Purity from HPLC, 98% or higher, with no large second peak beside the main one.
3. Identity confirmed by mass spec (LC-MS) as Melanotan II.
4. The right form: the closed ring, not the open chain.
5. Content in milligrams, close to the size on the label (10mg).
6. The report number on the product page matches the one at the top of the report.

Common questions

Is Melanotan II the same as Melanotan I?

No. Melanotan I is a straight chain of 13 amino acids with no ring, so it is a different molecule with its own report.

Why does the report say Melanotan-2?

It is the same name with the numeral written as a digit. What ties the report to the product is the report number, KVR-2026-3CB15D, which the product page lists with it.

Where do I find the Melanotan II report?

On the Melanotan II product page under Lab results, and on our research materials page, which lists every report.