Visual inspection can reveal gross degradation (cloudiness, particles, color changes), but a vial can lose 20 to 30% of its potency while still appearing perfectly clear and colorless
See Meto's overview of longevity peptide stacking for context on how clinicians think about combining these compounds
VGF has been reliably implicated in well powered multi-omic AD studies, with CSF 10,43,51,52 and cortical 6,11,12,13,18 depletion of VGF associated with AD and other dementia-types
In yet another study, researchers found that cigarette smoke prevented glutathione from reducing, therefore preventing it from performing its antioxidant duties as the reduced form of glutathione is the active form
Research Blog Guides, comparisons, and laboratory resources for peptide researchers
How Often Do People Typically Come in for B12 Shots