Most are administered via small subcutaneous injection a few times per week, though some are available as nasal sprays (Semax/Selank), oral capsules (Dihexa), or topical formulations (GHK-Cu)
Conclusions of a WHO technical consultation on folate and vitamin B12 deficiencies
For ligament work, the canonical reference is Cerovecki and colleagues 2010 study of medial collateral ligament transection in rats, in which intraperitoneal, oral (drinking water), and topical BPC-157 administration each produced consistent improvements in functional, biomechanical, macroscopic, and histological healing endpoints over a 90-day window (Cerovecki et al., 2010)
Some researchers report that peptides reconstituted in sterile water degrade faster than those mixed with bacteriostatic water, even when stored at the same temperature