Studied in models involving energy expenditure, substrate utilization, hepatic signaling, and metabolic adaptation pathways
Pharmaceutical-grade: the USP product from makers like Pfizer/Hospira is the reference standard, but as an end user it usually means a prescription or a pharmacy, and bottle sizes often run larger than a research setup needs
According to the National Academies of Sciences, Engineering, and Medicine (NAP), a safe highest level is called the tolerable upper intake level. Assessment of what amount is too much is based on animal and human studies, published evidence of adverse events, and professional agreement based on a committee of experts
Its important to remember that B12 shots are not a quick fix for energy levels or other health concerns
If you use sterile water, you can only draw from the vial once before contamination becomes a risk