Bacteria, dust, and skin oils can all degrade sensitive peptide chains
If you are considering BPC-157 for injury recovery, the most prudent path is to work with a physician familiar with peptide therapy, source only from reputable suppliers, use conservative doses for defined periods rather than open-ended continuous use, and monitor closely for any unexpected symptoms
Vidal-Alaball J, Butler CC, Potter CC (2006) Comparing costs of intramuscular and oral vitamin B12 administration in primary care: a cost-minimization analysis
Notes that high-dose niacin passes into breast milk and that lipid-altering doses could pose risks to nursing infants, recommending caution or avoidance of such doses during breastfeeding)
continue holding until you hear the second click, which indicates the injection is complete