From an experimental design perspective, the key hypothesis is not that the peptides duplicate each others effects, but rather that they might support different rate-limiting steps in repair, such as cell recruitment to the injury site, fibroblast function, extracellular matrix organization, angiogenesis, and the transition from inflammatory signaling to remodeling
You inject yourself
The thigh, buttocks, or upper arm are the best spots due to their muscle depth and ease of access
The most significant theoretical concern is BPC-157s pro-angiogenic activity because the same pathways that promote healing can theoretically support tumor growth in people with existing (possibly undetected) cancers
The difference was meaningful in research terms but small in absolute terms, which is why responsible framing presents AOD 9604 as a possible adjunct to diet and training, not a replacement for them