I have been on 500mg of HU for three or four years. I had no noticeable side effects. Recently, I down-sized, (sold a house moved, and bought a house within a week) it was very stressful for me (at 79) and suddenly my hair stated falling out, naturally I blamed the HU and we adjusted my dosage, 1st to Every-other-day and now 5 days a a week. I now believe it was the stress of the move, cause my hair is just fine now. Some people on here report fatigue and joint pain and various other complaints, that are common with old people. As I am one of them, I also have joint pain, tiredness and a constant runny nose. All better than a stroke IMHO!