I got a very tiny drop in my rbc's but aside from that I could not and will not tolerate HU as I call it the devil pill. I lost a year of my life on it having severe side effects; feeling like the worst flu everyday, my colitis came back full force which I was fine for yrs from it, severe! Weakness, pain I have that has become excerbated to the extreme and as fatigued as it made me I couldn't sleep at night even with an Ambien. I could go on and on all my other Drs PCP, nephrologist even a foot Dr I went to for a previous broken ankle all cringed when they found out I had started with HU a yr ago. They said it was a harsh drug and many people could not tolerate it. The cold hearted heartless Dr I was going to could care less about my symptoms and would try to make you think it was all in your head but insisted I would need this med for the rest of my life. I cry all the time from feeling so sick and feeling like has been passing me by. My sister and PCP kept saying to get a second opinion which I have an appt in 2 wks. It has already been 2 wks I went off the med completely and I still feel weak etc. I have CKD since I was a child and meds clear my system much slower than the average person and I found out HU goes through the kidneys for clearance . My dosages were 500mg five times a day then 3 times a week then two times a week until I got the jerk to go down to once a week. I didn't feel one but better. A pharmacist told me as long as your on the med no matter the dose you will always have side effects being the class of drug it is. My Dr went ballistic when I brought that up he will not tolerate any suggestions. I pray the new guy I go to is human with a heart. My PCP suggested this new Dr and told me he is a nice guy and a great listener. Good luck on your problem and think about a second opinion. Janet