Compare prices and buy Melanotan II from 42 research peptide vendors - also called suppliers or sources. Updated daily.
A cyclic synthetic heptapeptide analog of alpha-melanocyte-stimulating hormone (CAS 121062-08-6), shorter than the linear Melanotan I. It agonizes the MC1, MC3, MC4 and MC5 melanocortin receptors non-selectively, and its MC4 activity is linked to pro-erectile effects. It has no FDA approval, and FDA's compounding safety list cites published case reports of serious adverse events including melanoma and priapism.
For research purposes only. Not medical advice.
Melanotan II is a cyclic synthetic heptapeptide, CAS 121062-08-6, molecular formula C50H69N15O9, molecular weight 1024.2. Its structure is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. The seven residues correspond to positions 4 through 10 of alpha-melanocyte-stimulating hormone, with a lactam bridge closing the ring between the aspartate and lysine side chains. That bridge, together with the D-phenylalanine substitution, is what makes the molecule resistant to enzymatic degradation and far more potent than the hormone it derives from.
It sits between two other melanocortin compounds indexed here. Melanotan I is a different construction, a linear 13-residue analog, while Melanotan II is a shortened cyclic one. PT-141 is Melanotan II with the C-terminal amide converted to a carboxylic acid, keeping the same ring and the same seven residues. Melanotan 1 vs 2 sets Melanotan II's small clinical record and withdrawn FDA nomination beside Melanotan I's approval.
Melanotan II agonizes the MC1, MC3, MC4 and MC5 receptors without discriminating between them, and its pigmentation and erectile effects come from two different receptors on one molecule.
The first human study below recorded both pigmentation and spontaneous erections. PT-141 is widely described as the selective redesign that solved this, but its FDA label does not support that and ranks MC1R first in order of potency.
Melanotan II was designed and tested at the University of Arizona, and the controlled human record is small and runs from 1996 to 2000.
Dorr and colleagues reported the first Phase I evaluation in Life Sciences in 1996 (58:1777-1784), a single-blind placebo-controlled study in three male volunteers. It measured increased facial and upper-body pigmentation by quantitative reflectance, and also recorded spontaneous erections, mild nausea and somnolence.
Two crossover studies followed from the same group. Wessells and colleagues studied ten men with psychogenic erectile dysfunction in the Journal of Urology in 1998 (160:389-393), reporting clinically apparent erections in eight of ten and a mean duration of tip rigidity above 80 percent, by RigiScan, of 38.0 minutes against 3.0 on placebo. A 2000 study in Urology (56:641-646) extended the finding to men with organic risk factors, and also reported significantly higher sexual desire after active injection than after placebo.
That is the whole of it. ClinicalTrials.gov lists no Phase 3 trial of Melanotan II. Its Arizona designers named PT-141, Palatin Technologies' analog of it, in a 2006 review as the compound headed for pivotal Phase 3 trials, and that analog is the one that reached approval.
Melanotan II has no FDA approval, and the safety statement FDA attached to its Category 2 entry is still published after that entry was removed.
It was nominated for the Section 503A bulk drug substances list and placed in Category 2, the list of substances FDA says may present significant safety risks. The nomination was later withdrawn, and Melanotan II was one of the twelve peptides FDA announced removing from Category 2 on April 15, 2026, effective seven days later. That removal is administrative, makes no finding of safety and is not an authorization: the substance was not among the seven the Pharmacy Compounding Advisory Committee heard in July 2026, so it has not yet been reviewed for the permitted list. FDA has named it for the committee's next meeting, planned before the end of February 2027.
FDA moved the entry to the "nominated but withdrawn" table on the same page and, as it did for every entry there, kept its safety text attached, including published case reports of melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism.
Outside the United States, the UK regulator said in December 2021 that it had repeatedly acted to remove melanotan products from sale for over ten years, and had recorded 13 suspected adverse drug reaction reports associated with Melanotan II through its Yellow Card scheme between 2011 and 2021.
Vendor abbreviations for this compound collide with its sibling in a predictable way.
Nasal sprays are also listed, and they are catalogued separately without a per-milligram price.
PeptideScouter indexes each vendor listing per milligram where the format allows it, and verifies identity against the molecular formula rather than the product title.
No. Melanotan II has no FDA approval. Two closely related compounds are approved, which is a common source of confusion. Melanotan I is FDA-approved as afamelanotide (Scenesse) and is a linear 13-residue molecule, not this one. PT-141 is FDA-approved as bremelanotide (Vyleesi) and differs from Melanotan II by a single C-terminal amide converted to a carboxylic acid. Neither approval covers Melanotan II, and the material sold by the vendors indexed here is research-grade, labeled for laboratory use only.
Because it activates several melanocortin receptors without discriminating between them. Melanotan II is an agonist at MC1, MC3, MC4 and MC5. MC1R sits on melanocytes and drives eumelanin synthesis, which produces the pigmentation the compound is named for. MC4R is linked to the pro-erectile effects and is expressed in the spinal cord and in nerve fibers of the penis as well as in the brain. The two effects come from one molecule acting at two receptors, and the first human study recorded both. It is also why PeptideScouter catalogues Melanotan II under Skin and Cosmetic and discusses it on the Sexual Health category page rather than duplicating the row.
Melanotan II was one of twelve peptides the FDA announced removing from Category 2 of its interim 503A bulk drug substances list on April 15, 2026, effective seven days later, after the nominations were withdrawn. Removal on a withdrawn nomination is an administrative step, not a safety clearance or an authorization to compound: the Pharmacy Compounding Advisory Committee heard seven substances in July 2026 and Melanotan II was not among them, so it has not yet been reviewed for the permitted list. FDA has named it for the committee's next meeting, planned before the end of February 2027. The FDA kept the substance on the same page under a heading for substances nominated but withdrawn, and kept its safety statement attached. That statement says compounded drugs containing Melanotan II may pose a risk of immunogenicity for certain routes of administration, from aggregation or peptide-related impurities, and that published case reports discuss serious adverse events including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism.
Yes, in a small number of studies, all from the University of Arizona group that designed it, and all published between 1996 and 2000. Dorr and colleagues published the first Phase I evaluation in Life Sciences in 1996, a single-blind placebo-controlled study in three male volunteers that measured increased pigmentation by quantitative reflectance and also recorded spontaneous erections, mild nausea and somnolence. Wessells and colleagues then ran two double-blind placebo-controlled crossover studies. The first, in the Journal of Urology in 1998, studied ten men with psychogenic erectile dysfunction and reported clinically apparent erections in eight of ten and mean tip rigidity above 80 percent lasting 38.0 minutes against 3.0 on placebo. The second, a 2000 study in Urology in men with organic risk factors, recorded subjectively reported erections after 12 of 19 active injections against 1 of 21 placebo doses and significantly higher reported sexual desire. Severe nausea followed 4 of those 19 injections. ClinicalTrials.gov lists no Phase 3 trial of Melanotan II.
PeptideScouter computes a per-milligram price only for listings measured in milligrams and sold as a vial. Nasal sprays are catalogued as their own format and excluded, because a spray price bundles a delivery device and a prepared solution rather than pricing peptide mass alone, so a per-milligram figure would not be comparable to a lyophilized vial. Spray listings still appear on this page with their vendor, size and price. They are simply left out of the per-milligram table and out of the lowest-per-milligram figures quoted elsewhere on the site.
Melanotan II is sold by 42 research peptide vendors indexed on PeptideScouter, with 62 tracked listings compared per vendor in the table above. Pricing is normalized and refreshed daily.
41 of the 42 indexed vendors currently have Melanotan II in stock. The comparison table marks out-of-stock listings, and stock state is refreshed daily.
Studz Peptides currently lists Melanotan II at $1.66/mg, the lowest listed price across 42 tracked research peptide vendors. With current vendor discount codes applied, the lowest effective price is $1.49/mg.
Discount codes are issued per vendor rather than per peptide, so any code applies across that vendor's whole catalog. All 42 vendors listing Melanotan II publish a PeptideScouter code, worth 5% to 50% off. Applied, the lowest effective price falls from $1.66/mg listed to $1.49/mg at Studz Peptides. Each vendor's code is shown beside its price in the table above.
Melanotan II ranges from $1.66/mg to $9.50/mg across 62 listings from 42 research peptide vendors, normalized to USD per milligram and refreshed daily.
42 research peptide vendors currently list Melanotan II on PeptideScouter, with 41 in stock right now. We track 62 listings across size and kit variants.
Melanotan II's CAS Registry Number is 121062-08-6. It is also sold as MT-2, MELANOTAN 2, MLT II.
