The NICE Clinical Knowledge Summary for vitamin B12 deficiency outlines specific treatment schedules: for patients without neurological symptoms, hydroxocobalamin 1 mg intramuscularly three times a week for 2 weeks
This helps maintain healthy glutathione levels, scavenge free radicals, and provide foundational antioxidant support
Most are animal sources (milk, egg yolks, yogurt, salmon, tuna, beef) which is why vegetarians and vegans have a higher risk of being deficient (3)
Sulfenic acid formation and overoxidation of essential CYS61
So the responsible way to approach it is as antioxidant support with realistic expectations, not as a guaranteed cosmetic result
What they do know is that many conditions are associated with dysregulations or deficiencies in glutathione, such as: Neurodegenerative diseases like Parkinsons disease and Alzheimers disease Age-related cataracts, macular degeneration, and glaucoma as well as age-related hearing impairments Cancer Cardiovascular disease - especially hypertension and atherosclerosis