While it seems convenient, storing reconstituted peptides in plastic syringes for long periods can lead to degradation of the peptide, as it may adhere to the plastic
Still, their stability drops significantly after reconstitution most reconstituted peptides are considered reliable for no longer than 28 days under refrigeration, which is precisely why the shelf life of bacteriostatic water aligns so well with typical peptide usage cycles
Nature (2014) 4
In that case, a doctor will likely recommend B12 shots to get their levels up to where they should be
Tendon, Ligament, and Muscle Injury, Osteotendinous, Myotendinous, and Muscle-to-Bone Junction Therapy Perspectives with Growth Factors and Stable Gastric Pentadecapeptide BPC 157-A Review
It is essential to weigh such medications benefits against potential side effects