- Also known as
- MT-II · MT2 · Melanotan 2 · MT-2
- Class
- Melanocortin receptor agonist (MC1R, MC3R, MC4R, MC5R)
- Form
- Lyophilised powder (10 mg vial); nasal spray solution (10 mg / 10 mL)
- Sizes
- 10 mg
- Storage, dry
- −20 °C, dry and dark
- Storage, mixed
- 2–8 °C, use within 28 days of mixing (as generally reported for reconstituted peptides)
- BAC water per size
- 10 mg: 2 mL
- Molecular weight
- 1024.2 g/mol
What is Melanotan II?
Melanotan II is a synthetic, cyclic peptide analogue of alpha-melanocyte-stimulating hormone (alpha-MSH) that activates several melanocortin receptors rather than one. It is a lactam-bridged heptapeptide: a side chain-to-side chain bridge between Asp and Lys closes the ring. In cell work it binds and activates the human MC3, MC4 and MC5 receptors, and the Phe and Trp residues are needed for that activity. Through the MC1 receptor it raises skin pigmentation, which is why it is sold illicitly as a tanning agent. In rats it produces penile erection through brain and spinal cord melanocortin receptors, and in rodents it lowers food intake and body fat. Nearly all controlled data are from rodents, fish or cells; human information comes from case reports and studies of online user forums.
What the research shows
| Study | Model | Dose used | Duration | Finding |
|---|---|---|---|---|
| Wessells H et al.2003 · Ann N Y Acad Sci · PMID 12851302 | Rat (awake males; anaesthetised rats for intracorporal pressure) | Graded doses i.c.v., intrathecal and i.v.; optimal erectile response at 1 microgram i.c.v. and intrathecal | Single dose, erections scored for 90 min | MT-II produced dose-dependent penile erections through brain and lumbosacral spinal melanocortin receptors, blocked by SHU-9119. Injected directly into the penis it did not raise intracorporal pressure, so the action is central, not in the penis. |
| Strader AD et al.2007 · J Pharmacol Exp Ther · PMID 17567964 | Mouse (diet-induced obese and low-fat fed), replicated in diet-induced obese rats | Not stated in the abstract (peripheral administration) | Not stated in the abstract | Obese mice given MT-II lost weight and body fat, with reductions in both visceral and subcutaneous fat; low-fat fed mice kept their body weight. Pair-fed controls lost similar weight but kept more fat. |
| Seeley RJ et al.2005 · Endocrinology · PMID 15932932 | Rat, diet-induced obesity (some pre-restricted to different body weights) | Various doses by osmotic minipump (values not stated in the abstract) | 28 days | Whatever the starting body fat, final body fat was set by the MT-II dose, and MT-II rats had less body fat than vehicle rats. Food-restricted rats given MT-II ate more than ad libitum rats given MT-II. |
| Wekwejt P et al.2023 · Biomed Pharmacother · PMID 37478579 | Zebrafish, short-term high-fat diet | Not stated in the abstract | About three weeks of high-fat diet | A high-fat diet impaired recognition memory, raised anxiety-like behaviour and reduced exploration. Fish on the high-fat diet given MT-II behaved like the control-diet group. |
| Bednarek MA et al.1999 · Peptides · PMID 10447101 | Cell/receptor assays (human MC3, MC4 and MC5 receptors) and NMR | Not applicable (in-vitro binding and activation) | Not applicable | Swapping His for Ala left potency similar to MT-II, Arg to Ala cut potency about 100-fold, and Phe or Trp to Ala gave inactive compounds. Retro, enantio and retro-enantio analogues lost much of their potency. |
| Dreyer BA et al.2019 · BMJ Case Rep · PMID 30796078 | Human, single case report | Not stated in the abstract (abdominal subcutaneous injection) | Single presentation; 4-week follow-up | A man presented with low-flow priapism after injecting melanotan. It was managed without surgical shunting, but erectile function had not recovered at 4 weeks. |
| Peters B et al.2020 · CEN Case Rep · PMID 31953620 | Human, case report with literature review | Not stated in the abstract | Not stated in the abstract | The authors report a renal infarction most likely attributed to Melanotan II and note earlier reports of rhabdomyolysis and renal failure. They suggest a thrombotic effect and possible direct kidney toxicity as mechanisms. |
| Gilhooley E et al.2021 · Dermatology · PMID 34464955 | Human, qualitative study of online forums (623 entries, 205 participants, UK and Ireland) | Not stated in the abstract | Forum data from January 2016 to October 2017 | Users sought a tan before holidays and fitness or bodybuilding competitions. The authors flagged risks to pigmented skin lesions, infection, contaminated products, polypharmacy and sunbed use. |
What these studies don't show: There are no controlled human trials of Melanotan II in this record set. The human information is two case reports and a study of forum posts, so it cannot give event rates. The controlled findings on erection, body fat and behaviour come from rats, mice and zebrafish, and the abstracts often do not state the doses used. Nothing here shows long-term safety, or effects on moles and pigmented lesions over time.
Every study links to its PubMed record. See all Melanotan II studies in the research library →
Melanotan II price in Australia: 10mg vial
Buy Melanotan II in Australia in a 10mg vial, plus a nasal spray and a starter kit. Prices are in AUD, you pay by PayID or bank transfer, and orders are dispatched from Australian stock.
| Size | Price | Per mg | BAC water (example) |
|---|---|---|---|
| 10 mg | $79.99 | $8.00/mg | 2 mL |
The BAC water column is an example volume for the maths only. Open the calculator (pre-set for Melanotan II).
Other formats and kits
Is Melanotan II available in Australia?
Melanotan II is not registered on the ARTG, and there is no TGA-approved Melanotan II product in Australia. The related melanocortin peptide afamelanotide is registered, as Scenesse, for erythropoietic protoporphyria, but it is a different compound. Tasman supplies Melanotan II as a research chemical for laboratory use only, not for human use. How the TGA treats research peptides →
Side effects reported in studies
The human reports of Melanotan II side effects in these records are case reports: low-flow priapism after injection, and a renal infarction that the authors attributed to Melanotan II. In animal studies the measured results were penile erection and yawning in rats and lower body fat in obese rodents. Read more →
Doses used in studies
The only Melanotan II dose these abstracts give as a number is in rats: 1 microgram gave the optimal erectile response when given into the brain or spinal fluid (Wessells et al., 2003). A 28-day rat study used several doses by osmotic minipump, but the abstract does not give the amounts. These are research doses in animals, not guidance for people. Read more →
Reconstitution
| Vial | BAC water (example) | Concentration |
|---|---|---|
| 10 mg | 2 mL | 5 mg/mL |
Melanotan II FAQ
Where can I buy Melanotan II in Australia?
Tasman Peptides supplies research-grade Melanotan II from Australian stock, for laboratory research only. It comes as lyophilised powder in 10 mg vials and as a 10 mg / 10 mL nasal spray solution, and each batch is tested by HPLC. It is not registered on the ARTG and is not sold for human use, including tanning.
How much is Melanotan II per mg?
The cost per mg depends on the format, and the size table on this page lists every option. Melanotan II is sold as a 10 mg lyophilised vial and as a 10 mg in 10 mL nasal spray, so both hold the same 10 mg of peptide in different forms.
What is the difference between the Melanotan II vial and the nasal spray?
The vial holds 10 mg of dry, lyophilised powder that has to be reconstituted before use in an assay. The nasal spray holds 10 mg already dissolved in 10 mL, which is 1 mg per mL. The powder keeps longer frozen. The solution is ready to use but should be kept cold.
How should Melanotan II be stored?
Store the dry powder at −20 °C, sealed, dry and away from light. Once reconstituted, keep it at 2–8 °C and use it within 28 days, as is generally reported for reconstituted peptides. Keep the nasal spray solution refrigerated at 2–8 °C and do not freeze it.
Is Melanotan II legal in Australia?
Melanotan II is not registered on the ARTG, and there is no TGA-approved Melanotan II product. The related peptide afamelanotide is registered as Scenesse for erythropoietic protoporphyria, but it is a different compound. Tasman supplies Melanotan II as a research chemical for laboratory use only.
What is Melanotan II studied for?
Melanotan II is studied as a tool for probing melanocortin receptors. In the records here, researchers used it to map central erection pathways in rats and to study body fat regulation in obese rodents. It has also been tested on diet-related memory changes in zebrafish and on receptor structure-activity in cells.
Melanotan II vs Melanotan I: what is the difference?
Melanotan II is a small cyclic peptide that activates several melanocortin receptors. Melanotan I (afamelanotide) is a linear analogue of alpha-MSH. Afamelanotide is registered in Australia as Scenesse. Melanotan II is not, and its broader receptor activity is linked in rats to erection and yawning.
Melanotan II vs PT-141: how are they related?
PT-141 (bremelanotide) is a closely related cyclic alpha-MSH analogue that was developed for sexual function rather than pigmentation. Both act on melanocortin receptors. Melanotan II's rat studies show erection driven through brain and spinal receptors, the same pathway PT-141 research builds on. PT-141 has its own page with its own studies.
Is there human research on Melanotan II?
There are no controlled human trials of Melanotan II in the records on this page. The human information comes from two case reports (priapism and renal infarction), an online survey of users and a qualitative study of forum posts. The controlled results are from rats, mice, zebrafish and cell assays.
Is there a Melanotan II starter kit?
Yes. The Melanotan II 10 mg vial is also offered as a starter kit with the laboratory items needed to reconstitute it, such as bacteriostatic water. The kit contents are listed on the product page. Like the vial, it is for laboratory research only.
Compare with
Related compounds
PT-141
Melanocortin receptor agonist (MC3R and MC4R; cyclic alpha-MSH analogue)
Melanotan I
Melanocortin-1 receptor agonist (linear alpha-MSH analogue)
KPV
Melanocortin-derived tripeptide (C-terminal fragment of α-MSH)
GHK-Cu
Copper-binding tripeptide (Gly-His-Lys copper complex)