Is Melanotan I safe?

Its receptor selectivity means it is less likely to cause the nausea, flushing, and spontaneous erections associated with Melanotan II's MC4R activity, and it has an actual regulatory approval and clinical trial record behind it — unlike MT-II. But "safer than MT-II" is not the same as "safe to self-inject for tanning." The approved use is a monitored, clinician-administered implant at a specific dose and schedule; self-sourced injectable powder carries the same sourcing, purity, and mole-monitoring concerns that apply to MT-II.

No, and this is the single most important distinction to understand. Melanotan I (afamelanotide) is a linear peptide that acts mainly on MC1R and is FDA/EMA-approved as Scenesse for the rare disease erythropoietic protoporphyria. Melanotan II is a cyclic peptide that non-selectively activates multiple melanocortin receptors, including MC4R, giving it more pronounced effects on libido and appetite along with more side effects. Despite the name similarity, they are different molecules with different regulatory status, and most gray-market "Melanotan" for tanning is actually MT-II.

No. Afamelanotide (Scenesse) is approved by the FDA and EMA for a single narrow indication — increasing pain-free light exposure in adults with erythropoietic protoporphyria — administered as a clinician-placed implant. It is not approved anywhere as a cosmetic tanning agent, and no regulatory body has evaluated self-injected Melanotan I for that use.

The clinical trials measured pain-free light tolerance in EPP patients, a very different endpoint from sunburn prevention in the general population. Increased melanin provides some UV absorption, but it is not equivalent to sunscreen, and relying on it in place of SPF protection is not supported by the approval data.