In vitro studies examining receptor-independent growth hormone signalling
Are MIC B12 injections safe for people with kidney disease
All B 12 supplements have folic acid, and folic acid is toxic when taken in large quantities
What is missing There is no published human pharmacokinetic study of subcutaneous AOD-9604, no published human topical or intranasal exposure data, no Phase 3 efficacy trial, no long-term safety data beyond 24 weeks, and no published human cartilage or joint outcome data
Manganese peptide complexes (e.g., manganese tripeptide-1) have been explored as alternatives that avoid copper-related skin discoloration concerns while providing metal-dependent enzymatic activation
Due to the complicating factor of a shot and the extra cost, it seems the best route for most people is to focus on getting adequate B vitamins from food, and supplement as necessary.