At a glance
| Molecular size | Seven amino acids |
|---|---|
| Target family | Melanocortin receptors |
| Not interchangeable with | Afamelanotide or bremelanotide |
| Initial human pilot | Three volunteers |
| Regulatory context | Unapproved tanning products |
Overview
Melanotan II is distinct from afamelanotide, historically called Melanotan I, and from bremelanotide, the approved medicine derived from a related development pathway. Similar names do not make the compounds interchangeable. Interest in tanning comes from melanocortin signaling, but that receptor family also influences other physiological functions. Commercial nasal sprays and injection products have circulated outside an established approved tanning indication. Early experiments can demonstrate that pigmentation changes occur without proving that cosmetic use has a favorable benefit-risk balance. Uncertain composition and exposure in marketed products add a separate problem from uncertainty about the molecule itself.
How it works
Melanotan II activates melanocortin receptors involved in pigmentation and other central or peripheral responses. This broader receptor activity helps explain why tanning is not its only observed effect. The first small human pilot reported pigmentation along with nausea, somnolence, fatigue, and spontaneous erections. Mechanistic similarity to a natural hormone does not establish safe long-term stimulation or protection against ultraviolet-related disease.
The early human evidence is extremely small
The initial phase 1 pilot involved only three men. It documented pharmacologic effects, including pigmentation and prolonged spontaneous erections, alongside nausea and fatigue-related symptoms. A sample this small cannot estimate uncommon harms or establish a favorable long-term profile for widespread cosmetic use.
Supporting sources [1]
Pigmented lesions and uncertainty
A published melanoma case occurred after Melanotan II use together with sunbed exposure. A case report cannot prove which exposure caused the cancer, particularly with a known ultraviolet confounder. It nevertheless reinforces why changing moles and long-term skin outcomes require serious attention rather than assuming that induced pigment is protective.
Supporting sources [2]
Warnings concern both the molecule and the products
Australia’s TGA warns against tanning products containing melanotan, including nasal and injectable forms. Such products have not passed the same assessment as an approved medicine for that purpose. Product identity, purity, and actual exposure remain additional uncertainties; changing the route does not supply missing efficacy or safety evidence.
Supporting sources [3]
Reading this profile
Jurisdiction: United States: no approved tanning indication; Australian TGA warning also documented. Molecular class: Synthetic cyclic melanocortin heptapeptide.
This profile was written with AI-assisted research and checked against the linked sources. It has not been represented as a clinician’s review. Evidence summaries describe the cited studies and products; they do not establish that a separately purchased preparation is equivalent.
Sources & references
Follow the original material. Product labels define specific formulations and uses; trial registration describes a study and does not by itself establish benefit.
- Melanotan II pilot phase 1 study in three volunteers ↗Clinical trial source · Checked 2026-10-27
- Melanoma associated with Melanotan II and sunbed use: case report ↗Original research · Checked 2026-10-27
- TGA: warning on tanning products containing melanotan ↗Regulatory source · Checked 2026-10-27