Abels, Improved distribution analysis of cobalamins and cobalamin analogues in human plasma in which the use of thiol-blocking agents is a prerequisite, Clinica Chimica Acta, Volume 131, Issue 3, 15 July 1983, Pages 211-224, ISSN 0009-8981 Thakkar, K., & Billa, G
Because of this, oral versions are typically sold "for research purposes only" and are not intended for everyday consumer use
How long a B12 shot lasts depends on the form of B12 used in the injection, how severe your deficiency is, and how well your body absorbs the form thats being injected
It is manufactured in the USA and supplied in a sealed 30 mL vial for reliable storage and shipping
Something is clearly happening to a subset of users - and understanding why is the key to either avoiding it entirely or recovering if you're already there
A great product, so helpful for my vitamin b12 deficiency I have Pernicious Anemia so I need B12 injections to stay alive