Melanotan II
Cosmetic and Skincare
ABOUT
Melanotan II is a synthetic melanocortin analogue. A very small, early phase-I study in three volunteers documented melanotropic effects and adverse effects; this is not a modern efficacy or broad safety evidence base.
EVIDENCE OVERVIEW
Too little published work to judge either way
WHAT THIS MEANS
Insufficient evidence. Review the research and limitations before relying on this record.
IDENTITY
HALF-LIFE
HOW IT IS THOUGHT TO WORK
Melanotan II is a synthetic cyclic analogue of alpha-melanocyte-stimulating hormone. It is non-selective across melanocortin receptors: MC1R activation drives the melanogenesis it is used for, while MC3R and MC4R activation produces the sexual, cardiovascular and appetite effects, and MC2R-adjacent activity contributes to the wider effect profile. The non-selectivity is the source of the harm profile, not incidental to it.
PHARMACOKINETICS
No human pharmacokinetic study exists. It has never been submitted for regulatory review in any jurisdiction, so no label-verified exposure data is available. Its selective analogue bremelanotide (PT-141) has a labelled 2.7 hour half-life; melanotan II does not.
REVIEW
PUBLISHED PAIR RECORDS
with PT-141
Shared melanocortin-receptor activityBremelanotide (PT-141) and Melanotan II are melanocortin analogues. No curated direct combination study was identified. Their shared receptor-family activity is a reason for medical review, not proof of a particular combined effect or a safety conclusion.
Reviewed 19 Aug 2026with Melanotan-1 (MT-1)
Shared melanocortin-receptor activityMelanotan II and Afamelanotide are both melanocortin-receptor agonists, so they converge on the same receptor family rather than on separate mechanisms - but they are not interchangeable within it: melanotan II is non-selective across melanocortin receptors, has never been submitted for regulatory review, and carries a published case literature of priapism, rhabdomyolysis with acute kidney injury, renal infarction and melanocytic change; afamelanotide is an MC1-receptor agonist supplied as a bioresorbable implant, approved for erythropoietic protoporphyria, whose labelling records that no drug-interaction studies were conducted and that twice-yearly skin examination is recommended because it darkens existing naevi. Overlapping activity at MC1 drives pigmentary effects and at MC4 drives appetite, sexual and cardiovascular effects, so which receptors a pair shares determines which effects stack. No study has characterised any two of these given together. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 21 Aug 2026with Setmelanotide
Shared melanocortin-receptor activityMelanotan II and Setmelanotide are both melanocortin-receptor agonists, so they converge on the same receptor family rather than on separate mechanisms - but they are not interchangeable within it: melanotan II is non-selective across melanocortin receptors, has never been submitted for regulatory review, and carries a published case literature of priapism, rhabdomyolysis with acute kidney injury, renal infarction and melanocytic change; setmelanotide is a selective MC4-receptor agonist approved for defined melanocortin-pathway obesity, whose labelling records that no dedicated drug-interaction studies have been conducted. Overlapping activity at MC1 drives pigmentary effects and at MC4 drives appetite, sexual and cardiovascular effects, so which receptors a pair shares determines which effects stack. No study has characterised any two of these given together. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 21 Aug 2026HUMAN EVIDENCE
A small pilot phase-1 study was published in 1996, and development stopped there - the selective analogue bremelanotide was taken forward instead and became an approved product. No controlled efficacy trial of melanotan II was completed, and it has never been submitted for regulatory review in any jurisdiction. The human literature since consists almost entirely of case reports of harm. Regulators in the United States, United Kingdom and Australia have issued warnings against use.
REPORTED EFFECTS
The published case literature is unusually consistent and serious. Melanocytic effects: eruptive atypical melanocytic naevi, dysplastic change in existing naevi, and reported malignant melanoma including cases arising from pre-existing moles and one oral mucosal melanoma. Systemic: rhabdomyolysis with sympathomimetic toxicity and acute kidney injury after a single 6 mg injection (creatine kinase peaking at 17,773 IU/L), renal infarction after six months of use, refractory ischaemic priapism requiring surgical decompression with permanent erectile dysfunction reported, hypertension, and posterior reversible encephalopathy syndrome. The dermatological concern is not that it causes melanoma from nothing but that it may accelerate pre-malignant melanocytic lesions. Melanotan II was added to FDA's Category 2 interim compounding list in September 2023.
RESEARCH LIMITATIONS
A three-person exploratory study does not establish effectiveness or safety. It must not be used to infer a suitable dose, product quality, long-term outcomes, or use for any purpose. Peppy provides no protocol or dosing guidance.
CURATED SOURCES · 3