Vials should be equilibrated to room temperature under desiccant before opening to prevent moisture condensation
PT-141 (Bremelanotide) is a melanocortin receptor agonist that acts centrally on arousal pathways in the brain
The fix is to either use a slightly larger volume of solvent (dilute it more) to reduce the concentration, or keep the solution at a warmer temperature if possible (though dilution is the better solution)
AHK-Cu's copper-peptide structure gives it some advantage over larger molecules: peptides in the tripeptide size range are generally considered more permeable than larger protein fragments
PubMed Heiss, W.D., Brainin, M., Bornstein, N.M., Tuomilehto, J., & Hong, Z
Reduces oxidative stress in the brain, protecting neurons