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
To reduce irritation and lumps, it helps to rotate injection sites (dont inject the same spot repeatedly), inject into healthy skin (avoid bruised, scarred, inflamed, or irritated areas), and keep your routine consistent (many protocols are taken in the morning)
Convenience One injection instead of two
The injectable administration integrates easily with other peptide protocols