Melanotan I Is Not Scenesse

Your feed is full of the “Barbie tan” peptide. Here’s a plot twist: its older sibling already has an FDA approval. Same molecule. Very different thing.

The sibling is Melanotan I. Under the drug name afamelanotide, it’s the active ingredient in Scenesse, a prescription implant for a rare disease that makes sunlight physically painful. So is a vial labeled Melanotan I basically Scenesse? No. A shared molecule isn’t a shared product, and the gap between the two is the whole story.

Literature, not lore.

Wait, which Melanotan is which?

Both came out of the same University of Arizona research program, starting in the 1980s. Scientists there were tinkering with α-MSH, a natural hormone that tells pigment cells to make melanin, the brown pigment in a tan.

Melanotan I is a straight chain of 13 amino acids, the building blocks of peptides. It’s α-MSH with two letters swapped so it lasts longer in the body. It mostly hits one receptor, MC1R, the pigment switch.

Melanotan II is shorter, ring-shaped, and much less picky. It hits several receptors, including ones tied to appetite and arousal. That’s the one regulators keep finding in tanning nasal sprays. (Its story is in Melanotan II Is Not PT-141.)

Did it actually tan people?

Yes, in a small, careful study. In 1991, the Arizona team ran a randomized, placebo-controlled trial in 28 healthy men.

Skin darkened in the men who got the peptide. It didn’t in the men who got salt water. The darkening peaked one to three weeks after the shots ended, and everyone wore strong sunscreen the whole time.

That’s a real human clinical trial, just a tiny and short one. It showed the pigment switch works. It didn’t show long-term safety, and nobody turned it into an approved tanning product.

So how did it become a prescription drug?

By finding a group of people who really need a tan that doesn’t come from the sun.

Erythropoietic protoporphyria, or EPP, is a rare inherited condition. Light on the skin triggers intense burning pain, sometimes within minutes. Many people with EPP spend their lives avoiding daylight.

An Australian company, Clinuvel, took Melanotan I into trials under the name afamelanotide. In two randomized trials published in 2015, 74 adults in Europe and 94 in the US got either the implant or a placebo. People on afamelanotide spent more hours in direct sunlight without pain.

Europe authorised it in 2014. The FDA approved Scenesse in October 2019, for adults with EPP, inserted under the skin by a specially trained clinician. It isn’t approved for tanning anywhere.

Same molecule, different product

Here’s the trap. The sequence is identical. The thing in your hand isn’t.

Scenesse is a finished medicine: a sterile implant made under drug-manufacturing rules, with a label, a specific patient group, and a trained clinician on the other end. A research vial is a dried powder made for lab work. Same words, different book.

The molecule is the words. The medicine is everything printed around them.

That’s also why a TGA lab test this August made headlines. Australia’s regulator tested seized Melanotan II nasal sprays with identical labels. Some bottles held more than twice as much peptide as others. The regulator also lists new moles and freckles among reported problems with Melanotan II, and dermatologists there told ABC News they’re seeing abnormal moles in people using it.

What’s new this fall?

On October 1, Clinuvel presented new patient cases at Europe’s big dermatology meeting. They were people with vitiligo, the condition where skin loses pigment in patches, treated with afamelanotide plus narrowband UV light therapy.

The photos looked good. But a handful of cases is early human research, and the company chose which ones to show. An earlier pilot found the peptide alone didn’t bring color back. The light therapy had to start the process.

The real test is a 210-person trial called CUV105, with results expected in December. We’ll read it when it lands.

What about the vial on a research shelf?

Inspired Labs carries Melanotan I as a research reagent. It shares a sequence with afamelanotide. It isn’t Scenesse, isn’t a trial product, and isn’t a tanning product.

Read any research lot, ours included, by its lot number and its certificate of analysis. The COA for our Melanotan I lot isn’t posted yet. Until it is, here’s how to read one when it arrives: How to read a certificate of analysis.

Research Use Only means laboratory research, not use in people. That fence stays up no matter how good the tan looks on someone’s feed.

The one thing to remember

Melanotan I is the same molecule as an FDA-approved medicine, but the approval belongs to the implant, the label, and the patients, not to the molecule in any vial.