Potential interactions with other peptides are also poorly understood
Many sublingual supplements provide between 1,000 mcg and 5,000 mcg per serving, although the appropriate amount depends on individual needs and should follow the product label or your healthcare provider's guidance
Publisher American Journal of Sports Medicine Accessed Jun 27, 2026 Study type Systematic Review Limitations: A clinician primer is contextual
Fatigue, brain fog, tingling in the hands or feet, and irritability are common symptoms
Elderly Individuals : The stomach acid formation decreases with age and stomach acid is necessary for the intake of vitamin B12 from the diet
Bottom line: interesting scienceno proven human benefit, and unknown long-term safety