The increase in melanin certainly will have some direct effect...

The increase in melanin certainly will have some direct effect but there’s a lot more going on than that I believe. Melanocortins have widespread effects and MT2 and Afamelanotide bind to different receptors although there’s definitely some overlap, probably on the receptors of most interest. I think a lot of the positive effects are from reduction in inflammation and upregulated DNA repair which I presume are independent of melanogenesis although not totally separated.

The binding affinity and half-life I think are also quite different between the two molecules.

This is why I don’t think it’s wise to compare what’s on the unregulated markets vs Clinuvel’s Afamelanotide. Don’t get me wrong though, in no way am I suggesting that I don’t think Afamelanotide is effective at reducing sunburn and skin cancer or provideing a host of other benefits.