No problems with Stevia. I use a tsp in my morning espresso and one tbs in each of my protein shakes each day. I only use Stevita brand though, so perhaps the migraine trigger could be due to some additives or impurities in other brands. SG if you suffer recurring migraine you should buy some pure pharmaceutical grade magnesium glycinate. I use purebulk.com for pharma grade stuff. oral mag is not well absorbed so you need a formulation with exceptionally good bioavailability. 400mg a day of elemental magnesium (2200mg mag glycinate) completely stopped my migraines.