Hi @lyd0218
I am 81 and have ET JAK2 mutation, I started taking HU 500 mg daily in 2022. I had a few lightheaded feelings, fatigue, and headaches. Then my hematologist changed me to every other day and it was much improved. I found later that taking it immediately after eating works better for me. It is very important to drink 64 ounces of fluids daily to rid any toxic effect of HU.

Best wishes, Eileen