So, after using these for a few weeks on and off I've had bad Migraine headaches immediately upon awaking up the next morning. Open my eyes and BAM! Aura! I stopped taking them for days at a time and didn't get a headache on days following. So, upon further research, I've found that the ingredient mannitol is a trigger for many people that suffer from occasional migraines. Hmmm, I've used liquid vegan b12 sprays in the past with no problems and with none if the additional ingredients that these tabs have. I guess I'll give what's left to my husband....disappointed