Melanotan II
Melanotan II is an unapproved synthetic melanocortin agonist originally researched for tanning and erectile dysfunction, now sold illegally online and linked in case reports to serious adverse events.
Regulatory status: Not approved by any regulator anywhere. It was a discontinued research compound and is now sold as an unlicensed injectable; published case reports link its use to renal infarction and priapism, and a 2009 BMJ report described unsupervised use in the general population.
Default vial
10 mg
Default mix
2 mL
Reported range
0.25–1 mg
Draw (U-100)
5 u
Start at the low end and titrate. Degrades faster than most peptides — use within ~2–3 weeks of reconstitution.
What it is
- A synthetic cyclic analogue of alpha-MSH that acts as a non-selective melanocortin receptor agonist at MC1R, MC3R and MC4R.
- Early academic interest was in erectile dysfunction and tanning, using subcutaneous injection.
- It was never advanced to approval; a selective analogue, afamelanotide, was developed and approved separately.
- It now circulates as an unregulated grey-market injectable.
How it is described to act
- 1
Self-administered by subcutaneous injection outside any clinical framework.
- 2
Distributes systemically, with unpredictable exposure given unregulated dosing and purity.
- 3
Non-selectively activates melanocortin receptors, including MC1R for pigmentation and MC4R for sexual and appetite pathways.
- 4
Observed in case reports as hyperpigmentation, priapism and vascular events including renal infarction.
What the research has looked at
Early clinical pharmacology
- Wessells et al. (J Urol, 1998) reported that a synthetic melanotropic peptide initiated erections in men with psychogenic erectile dysfunction in a double-blind, placebo-controlled crossover study.
Reports from illicit use
- A 2009 BMJ report described self-injection of Melanotan I and II obtained online, outside medical supervision, and flagged skin darkening and new or changing moles as clinical concerns.
- Clinicians reported a case of renal infarction possibly linked to Melanotan II use, with literature review (CEN Case Reports, 2020).
- A separate case report described Melanotan-induced priapism requiring medical intervention (BMJ Case Reports, 2019).
Strength of evidence: Preclinical evidence only
Some early-phase human pharmacology exists for the parent research compound, but there is no approved product, no modern controlled trial base, and the current literature is dominated by adverse-event case reports from illicit use.
What is published comes from cell and animal studies. Findings in those models frequently do not carry over to people.
Reported cautions and unknowns
- Case reports describe priapism requiring medical intervention.
- A case report and literature review linked its use to renal infarction.
- The 2009 BMJ report flagged unpredictable dosing, unsupervised use, and skin darkening or changing moles as reasons for clinical vigilance.
- Because the product is illegally sourced, contamination, mislabelling and dosing inconsistency are additional unquantified risks.
References
- 1.Wessells H et al. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction, J Urol (1998)
- 2.Use of melanotan I and II in the general population, BMJ (2009)
- 3.Melanotan II: a possible cause of renal infarction, CEN Case Rep (2020)
- 4.Melanotan-induced priapism, BMJ Case Rep (2019)
Handling this vial
- Lyophilized vials are generally stored at 2–8 °C and kept out of light; once reconstituted with bacteriostatic water they are refrigerated and commonly discarded after 28 days.
- Mix by aiming water down the vial wall and rolling gently — do not shake — and never re-freeze a reconstituted vial.
- Pep-Tidy cannot verify what is in your vial. Ask your supplier for a current Certificate of Analysis (HPLC/MS).
Melanotan II questions people ask
How do you reconstitute Melanotan II?
A common starting point for a 10 mg vial of Melanotan II is 2 mL of bacteriostatic water, which gives 5 mg per mL. Aim the water down the inside wall of the vial, let it dissolve on its own, and roll gently instead of shaking. Pep-Tidy's reconstitution calculator will recalculate the numbers for any other vial size or water volume you use.
How many units of Melanotan II is one dose?
At 5 mg per mL, that works out to about 5 units on a U-100 insulin syringe for a 250 mcg dose. Change the vial size, water volume, or target dose in the calculator and the syringe reading updates with it. This is arithmetic, not a dosing recommendation.
What dosing schedule is reported for Melanotan II?
Published and community sources describe 0.25–1 mg, subcutaneous, every day, typically run 2 weeks on and 2 weeks off. These figures describe what has been reported, not what anyone should take — talk to a licensed clinician first.
How should Melanotan II be stored?
Lyophilized Melanotan II vials are generally kept at 2–8 °C and out of light. Once reconstituted with bacteriostatic water they are refrigerated and commonly discarded after about 28 days. Never re-freeze a reconstituted vial and never shake it.
Read this before you act on anything above
Everything on this page is a summary of what other people have published — it is not medical advice, not a recommendation, and not a dosing instruction. Reported dose ranges describe what appears in the literature or in community protocols, not what anyone should take. Talk to a licensed clinician before using any peptide.