Levoxyl Side Effects: I have been on Levoxyl for 3 years, changed from Synthroid. I hav http://www.medications.com/effect/view/27020 I have been on Levoxyl for 3 years, changed from Synthroid. I have gained about 20lbs a year for the last 3 years, suffered headaches, stomach problems, dizziness and nausea. The last couple of months I have had migraines or bad headache more often, just ab did you feel better after switching back to Synthroid? Fri, 29 Aug 2008 07:50:00 -0400 http://www.medications.com/effect/view/27020?item=11740 did you feel better after switching back to Synthroid? http://www.medications.com/effect/view/27020?item=11740