Watch for cloudiness, visible particles or precipitate, a color shift (most peptides are colorless GHK-Cu is the exception and reads blue, which is normal), or foam that will not settle
Injections are good at treating more severe deficiencies, says Foxx
PLoS Pathog 7:e1002251 Griffin JE, Pandey AK, Gilmore SA, Mizrahi V, McKinney JD, Bertozzi CR, Sassetti CM (2012) Cholesterol catabolism by Mycobacterium tuberculosis requires transcriptional and metabolic adaptations
On the other side, long-term human safety data, standardized dosing protocols, and controlled efficacy trials remain extremely limited
This complexity is precisely why peptides are interesting