what does bac water stand for Bacteriostatic Injection Bacteriostatic Water: What It Is

A COA is a batch-specific lab report that documents the identity, purity, and quality control results for the production lot you receive

They correspond to two different documented protocols and per-dose amounts (150 mcg vs 2.5 mg)

Vitamin B12 Injections: The Direct Approach Vitamin B12 injections deliver the nutrient directly into muscle tissue, bypassing the digestive system entirely

Role of Vitamin B12 in Boosting Immunity Vitamin B12 is intricately linked to immune system function

Yin L, Chen X, Lu X, An Y, Zhang T, Yan J

Its hard to say with a high level of certainty what AHK-Cu dosage you should take without knowing more - how are you taking it