Does MT2 cause melanoma?
Nobody has shown causation. There are published case reports of melanoma in users and a plausible mechanism, and no controlled study large enough to rule it out. That is the honest state of the evidence.
No human trial data
Melanotan II (MT-2) Side Effects
No approval and no controlled human trial — what is known comes from early clinical studies and published case reports
Melanotan II is a non-selective melanocortin agonist that was abandoned in development and is sold only as a research chemical. The human literature is small early studies plus case reports: nausea, flushing, spontaneous erections, and pigmentary changes including darkening or new moles are consistently described, and there are published case reports of melanoma and of rhabdomyolysis in users. No frequency figures exist that we would print.
Research-use information only. Research-grade Melanotan II is not an approved medicine; where trial or label figures appear below they belong to the pharmaceutical product studied, not to any research vial. This page does not give dosing or medical advice.
What is reported
Every rate carries its source. Where no source exists, no rate is printed.
| Effect | Rate (sourced) | Detail | Source |
|---|---|---|---|
| Nausea, facial flushing, yawning, spontaneous erections | not quantified | Described in early human studies of MT-II (Dorr et al. 1996; Wessells et al. 1998). | Early clinical studies |
| Darkening of existing naevi, new naevi, generalised hyperpigmentation | not quantified | Repeatedly reported in dermatology case series. | Case reports / dermatology literature |
| Melanoma in users | not quantified | Published case reports; causation is not established but the concern is mechanistically plausible. | Case reports |
| Rhabdomyolysis, renal infarction, priapism | not quantified | Isolated case reports. | Case reports |
What is not known
- •Frequency of any of the above — there is no controlled trial.
- •Long-term consequences of repeated melanocortin stimulation.
- •Research-grade identity and dose.
Mechanism-based cautions
- •Non-selective MC3R/MC4R/MC1R activity: sexual and cardiovascular effects alongside pigmentation.
- •Anyone with atypical naevi or a melanoma history should treat the pigmentary signal as a red flag.
Regulatory status: Not approved anywhere; several national regulators have issued public warnings about melanotan II.
References
- Dorr RT, et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a single-dose trial. Life Sciences, 1996.
- Wessells H, et al. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction. Journal of Urology, 1998.
What is actually in a research vial
Everything above describes Melanotan II the molecule. The risk specific to a research vial is different: it may not contain Melanotan II at the labelled amount, and it may contain what the synthesis left behind. Identity (mass spectrometry), purity (HPLC), measured net content and an endotoxin result are the four lines on a certificate that bear on adverse effects, and only a certificate you can check at the laboratory tells you any of them. This is what we have verified for Melanotan II so far.
Who sells Melanotan II, and what they document
10 of the 77 vendors on our scoreboard list Melanotan II with a price we read on the product page (23 Sept 2026–2 Oct 2026). Of those, 10 name their testing laboratory, 7 publish certificates that resolve on the lab's own site, and 9 publish measured milligrams against the label. The full ranking, with every dated price, is on Best Melanotan II Vendors.
| Vendor | Rubric | Lab named | Price read |
|---|---|---|---|
| Purgo Labspartner | 10/10 | SteriGenix · Freedom Diagnostics | $36.99 · 10mg · 2 Oct 2026 |
| Rivn Peptidespartner | 9/10 | Freedom Diagnostics | $39.99 · 10mg · 23 Sept 2026 |
| TrustedPepspartner | 9/10 | Freedom Diagnostics (on certificates) | $20.00 · 10mg · 23 Sept 2026 |
| Everest Peptides | 8/10 | Freedom Diagnostics | $33.74 · 10mg · 23 Sept 2026 |
| PS Peptidespartner | 8/10 | North American Diagnostics | $39.99 · 10mg · 23 Sept 2026 |
Top 5 by rubric score; 5 more on the ranking page.
Melanotan II certificates we have opened
None yet for Melanotan II specifically. The COA library holds the certificates we have read for each vendor on other compounds, which is the next best signal of how that vendor documents a lot.