Poor-quality peptides may contain contaminants, incorrect concentrations, or degraded product that could increase side effect risks or reduce efficacy
[12] If a pregnant patient has a true biotin deficiency (which is rare), a doctor may prescribe biotin supplementation, and this would be managed carefully
No human safety data : The complete absence of human clinical trials means the safety profile, side effects, optimal dosing, and pharmacokinetics in humans are entirely unknown Animal-to-human translation is uncertain : Metabolic differences between mice and humans mean that the magnitude of effects (e.g., weight loss, grip strength improvement) may not translate
That direct route matters because the most common reason people run low is not diet, it is a problem absorbing B12 through the gut, and an injection sidesteps that problem entirely