In plain terms, that flagged them for safety-data concerns and effectively stopped licensed compounding pharmacies from preparing them
[DOI] [PubMed] [Google Scholar] 43.Japjec M., Horvat Pavlov K., Petrovic A., Staresinic M., Sebecic B., Buljan M., Vranes H., Giljanovic A., Drmic D., Japjec M., et al
If you're concerned about the side effects of B12 shots or patches, you don't need to worry since there are only a few side effects
Research shows B12 helps sperm in several ways: It improved sperm motility by about 50% after eight weeks of methylcobalamin treatment (1500 g/day) [17] Sperm DNA showed 22.1% less fragmentation after taking multivitamins with B12 [17] Sperm survived better during freezing when scientists added 2 mg/ml vitamin B12 to the storage medium [18] B12 supports male reproductive function in multiple ways, including reducing oxidative stress in seminal fluid