Two melanocortin-system peptides that get mentioned together, but their research records are worlds apart. One is an FDA-approved drug with human trials behind it; the other is a research chemical with almost no controlled human evidence.
PT-141 (bremelanotide) is FDA-approved as Vyleesi and carries a real human RCT evidence base, which is why it leads decisively on study design, sample size, and replication. Melanotan II has never been approved for anything and has been studied almost entirely in early or animal work, with its widespread use for tanning sitting far ahead of any controlled human research.
There is one counterintuitive line in the data worth explaining: Melanotan II actually scores higher on funding independence (7 versus 4). That is not a point in its favor so much as an artifact of how little industry money has ever touched it, the small body of Melanotan II research is academic because no company developed it, whereas PT-141's trials were largely manufacturer-sponsored. More independence over a nearly empty evidence base is not the same as stronger evidence.
Everywhere it matters for research maturity, PT-141 is far better evidenced. The 31-point gap is one of the widest among compounds people casually pair, and it reflects the difference between an approved, trialed drug and a substance that remains essentially uncharacterized in controlled human studies.
So the honest framing is not "which melanocortin peptide is better." It is that these two are not really peers on the evidence at all. Melanotan II is not approved for any use, and its low score reflects how little controlled human research exists, not a verdict on the compound itself.