KPV — three amino acids. Is there anything to it?

KPV is a tripeptide, which seems remarkably small to be doing anything specific. Is size a problem here or an advantage?

Both, and it depends what you want from it.

Small is an advantage for stability and for getting anywhere — fewer bonds to hydrolyse, fewer oxidation-prone residues, better prospects of crossing something. It is a disadvantage for specificity: three residues is not much of a binding surface, so selectivity is generally poorer than a longer sequence would manage.

KPV is the tail end of alpha-MSH and the anti-inflammatory activity is attributed to that fragment. Same design logic as the growth hormone fragments — take the bit associated with the effect you want, leave the rest.

evidence: none, same as most of the recovery category.

Understood. Small buys stability and costs specificity.