Reducing sertraline 50 to 25 mg slowly after long term use. i've had 2 migraines in the last 5 days (unusual). ssri withdrawal? recommendations?

Try oral magnesium: You may be deficient in magnesium and even if you are not deficient you may benefit from adding small increments gradually.Magnesium acts as a vasodilator in the brain.

Not sure: A slower wean than what you are already doing would cure the possibility of any withdraw type symptoms, but discuss any medicine dosing changes with your doctor first. If migraines persist, may not be related, and then get eval for them too. Good luck to you.