However, a very small percentage of B12 from a supplemental dose is absorbed by passive diffusion, rather than by intrinsic factor, such that vegans can make up for taking B12 only once per day, or even only once per week, by taking larger doses than normally provided by food
Bought from an unverified online seller, none of those safeguards exist, which is where most peptide problems begin
References 1 National Center for Biotechnology Information (NCBI)Human chorionic gonadotropin: structure, function and LH/CG receptor binding mechanism
Even a single use dulls the tip and increases the risk of introducing bacteria into the vial or your body
doi:10.1002/14651858.CD007411.pub4
It is especially useful in conditions where oral supplementation is not suitable or effective, such as in critically ill patients, ICU cases, severe vomiting, or in patients with poor compliance to oral therapy