I have been taking daily 600mgs of HU for 6 yrs (Droxia formulation). When I started I didn't like how I felt when I took 1000mgs every other day, alternating with 500mgs. I suggested using Droxia so I could have the same dose each day, and my hematologist agreed and said to take 600mgs/day. I'm 77, PMF, JAK2+, with elevated platelets, which have lowered to normal in the past year. Fortunately, I haven't had much trouble tolerating the Droxia.