Tan Lines

The timeline

One origin, three strands, forty years.

Melanotan II starts as a single idea in a University of Arizona lab and splits into three separate stories. Read down the spine to watch them diverge — and to see the one strand that still hasn't paid off.

  1. 1960s–70s

    The mission

    The signal is mapped

    Endocrinologists work out that a family of melanocortin peptides — α-MSH chief among them — is the body's own instruction to make pigment. Natural α-MSH is too fragile to be a drug: it breaks down within minutes of reaching the blood.

  2. 1980s

    The mission

    The Arizona program begins

    At the University of Arizona — a state with some of the harshest UV in the country — chemist Victor Hruby and biologist Mac Hadley set out to engineer stable α-MSH analogs. The premise is public-health-scale: a protective tan induced pharmacologically, before sun exposure, as built-in defense against melanoma.

  3. late 1980s

    The mission

    Two peptides, one number apart

    The stabilized linear analog [Nle⁴-D-Phe⁷]-α-MSH becomes Melanotan I (later named afamelanotide). A smaller, more potent cyclic cousin — active across more of the receptor family — becomes Melanotan II. Both are patented; both structures enter the public literature.

  4. ~1990s

    The spinoffs

    The accident that redirected everything

    Testing MT-II, a member of the research team self-administers the compound and develops a prolonged erection — evidence that the peptide reaches central melanocortin circuits far beyond the skin. That off-target effect, not the tan, becomes the most valuable thing anyone found in the vial.

  5. late 1990s–2000s

    The spinoffs

    Industry splits the shotgun into rifles

    The melanocortin IP is licensed out. MT-II itself is dropped as a drug candidate — too non-selective to be safe as a lifestyle tan — while its individual effects are pursued as separate, targeted molecules. The erection observation is developed into bremelanotide (PT-141).

  6. mid-2000s

    The gray market

    The gray market forms

    Because the structure is public, any capable peptide lab can make MT-II. "Research chemical" sites sell vials labeled not for human consumption; bodybuilding and tanning forums supply the injection protocols. The press dubs it "the Barbie drug" for its tan-plus-appetite-plus-libido profile.

  7. late 2000s

    The gray market

    Regulators sound the alarm

    Health agencies in the UK, Australia, Denmark, Norway and elsewhere issue public warnings against Melanotan and move to block sales. The warnings document the risks — unverified contents, changing moles, no safety data — but they don't end the market.

  8. 2014

    The spinoffs

    Melanotan I gets approved — in Europe, for a rare disease

    Developed properly over decades by Clinuvel, afamelanotide (SCENESSE) — chemically the original Arizona Melanotan I — is approved by the EMA. Not as a consumer sunscreen, but as a subcutaneous implant for erythropoietic protoporphyria (EPP), a rare disorder in which light causes searing pain.

  9. Jun 2019

    The spinoffs

    The libido rifle lands: Vyleesi

    The FDA approves bremelanotide (Vyleesi) for hypoactive sexual desire disorder in premenopausal women — the deliberate, purified descendant of MT-II's accidental side effect.

  10. Oct 2019

    The spinoffs

    The FDA approves SCENESSE

    Afamelanotide reaches the US market for EPP — the first melanocortin photoprotective drug ever approved by the FDA. The molecule clears the bar. The indication stays narrow: a rare disease, a specialty implant, rare-disease pricing.

  11. Nov 2020

    The spinoffs

    The appetite rifle lands: Imcivree

    Setmelanotide (Imcivree) is FDA-approved for rare genetic obesity syndromes, targeting the MC4R pathway — the third distinct medicine drawn out of MT-II's effect profile, and again for something other than a tan.

  12. Today

    The mission

    The original goal is still open

    Three approved drug lineages, none of them the durable, general-public photoprotective tan the Arizona team set out to build. That product still does not exist — while gray-market MT-II keeps circulating in its place. Whether photoprotection ever gets its GLP-1-style breakout is the question this site is here to watch.

The strand that started it all is the one still waiting. For why a safe, approved, general-public photoprotective drug hasn't arrived — and what it would take — readThe middle-ground agonist already exists.