They're being used off-label for increasing growth hormone and IGF-1 for the sorts of things we're talking about here
Glutathione Synthesis in Cancer Cells
Cell 153(6):11941217 Martinez-Villaluenga C, Peas E, Ciska E, Piskula MK, Kozlowska H, Vidal-Valverde C, Frias J (2010) Time dependence of bioactive compounds and antioxidant capacity during germination of different cultivars of broccoli and radish seeds
This is largely because peptides are highly selective , meaning they target specific cells with precision, which results in a very low risk of side effects compared to traditional medications
[70] The situation in mammals is even less clear
5% Blue Copper Peptide Intensive Repair Cream: The Pinnacle of Anti-Aging 1