Some companies publish full third-party testing data
My skin LOVES The Lamelle Corrective Vita C Lipid Serum R985
The Science Behind GHK-Cu and Skin Tightening The skin-tightening effects of GHK-Cu stem from its documented ability to stimulate production of the structural proteins that maintain skin firmness while simultaneously inhibiting their breakdown
[18] Low-dose gliotoxin can exert antioxidant activities in the presence of the thioredoxin redox system that can counter the release of ROS in cells as a result of the electron transport chain (ETC) during cellular respiration
Kogure Y, Kanda H, Wang S, Hao Y, Li J, Yamamoto S, et al
and in what follows I don't mean to detract from their work or their vegan philosophy.) Unfortunately, for me my particular brush with veganism was a catastrophe