In other words, the preservative is the reason the product sits in a different handling class from preservative-free sterile water
Nature Reviews Immunology , 9 (11), 799809
Serious side effects are rare but can happen in some people
And B12 isnt likely to boost energy unless youre deficient
Warning signs include persistent fatigue despite adequate sleep, cold intolerance (especially cold hands and feet), menstrual irregularity or cessation in female subjects, hair thinning or shedding, and mood disturbances (irritability, low motivation)
Treatment plans that address gut health frequently produce significant mood and cognitive improvement alongside the GI benefits