The main difference in GHK-Cu vs BPC-157 is that GHK-Cu is more often associated with collagen and skin regeneration pathways, while BPC-157 is more often associated with tendon, ligament, muscle, gut, and systemic recovery pathways
For instance, a vial of peptide or vaccine may instruct add 2 mL of sterile water in such cases bacteriostatic water can be used if suitable
A friend from my running club mentioned BPC-157 after his own recovery from patellar tendonitis
NAD+ / B-12 / SEMAX (nasal) A nasal spray combining NAD+, methylcobalamin, and the neuroprotective peptide SEMAX
have chosen to use Methylcobalamin for its active absorption status which means it can be absorbed directly into the blood stream via the mouth area of the cheek and under the tongue and via the small intestine
This is the key advantage over plain sterile water, which must be discarded after a single use