Some doctors recommend injection or nebulized glutathione, both of which have their uses
Those medications have undergone extensive testing and are regulated by the FDA
The following summarizes what published research supports at the ingredient level, attributed as such - not as evidence of whole-product outcomes
CAS 946870-92-4) is a recombinant analog of human insulin-like growth factor 1 in which the native 70-amino-acid sequence is extended at the N-terminus by a 13-amino-acid sequence and carries an arginine-for-glutamate substitution at position 3 (E3R)
Human research remains limited, and potential risks such as immunogenicity may exist when sourced from unregulated materials
Adverse reactions reported following methylcobalamin administration include headache, infection, nausea/vomiting, paresthesias, and rhinitis