Peptides that often need acetic acid water: GHK-Cu (the copper complex is poorly soluble in neutral water), AOD-9604 (often forms a gel without mild acid), IGF-1 LR3 (acidic conditions prevent aggregation), Fragment 176-191, and sometimes Melanotan I and II depending on the batch
Cancer Cell 29(4):508522 Ferrara N, Gerber HP, LeCouter J (2003) The biology of VEGF and its receptors
So happy I found them
Moreira PI, Santos MS, Sena C, Nunes E, Seia R, Oliveira CR (2005) CoQ10 therapy attenuates amyloid beta-peptide toxicity in brain mitochondria isolated from aged diabetic rats
Anecdotal reports from online communities describe water retention and jaw and brow changes with high-dose long-term use, but these are not systematically collected data