What are most common side effects when starting HU (Hydroxyurea)?

I have Essential Thrombocythemia. Started with 3 pills weekly of hydroxyurea, and now at once a day as my platelets were not going down enough. I was told to take in the am with my other meds and vitamins. Gave me diarrhea. I decided on my own to take hydroxyurea in the evening after dinner. Fewer tummy problems. Other than softer stools, not much of an adjustment. I have started to have very vivid dreams, often pretty weird ones, that linger and stay with me after waking. But nothing really frightening. Other than that, so far so good.

Your doctor will decide your HU dosage.
Four mo ago my platelet count was 1.1 million.
I take 500 mg daily HU and my platelet count is 600k.
It’s still going down and I feel better than 4 mo ago.
The worst of the side effects - because we read everything before seeing the doc - was later explained is for other diseases with 8,500mg daily!
Everyone reacts differently but my side effects lasted a few weeks.
I have slight hair loss, stomach ok, just fatigue. I’ve had long Covid so I can’t always attribute symptoms….
Make a list of questions to discuss with your doc. My list gets shorter with each visit!

When I first started taking HU I had taken it 500 MG 9 days in a row. It brought my platelets down to the normal range but I felt awful. I had so much fatigue and bone pain. They then started me on the 500 MG 3 times per week MWF. I am ok with that dosage. I will have a tired day once in a while and bones aching/hurting especially my shins. My platelets are creeping back up so he may change my dosage . I have lost some hair but not bad, It is NOT coming out by the handfuls. My Dr said that was not one of the side effects. I told him it may not be but mine was not coming out before HU. I was diagnosed in August of 23. I have requested a second opinion with the Mayo Clinic. Praying for the best for you!!

Thank you for the response. I already naturally have lots of hair fall. It also tends to fall more when I'm under stress or losing weight.
I definitely don't want to add to it, lol. When I looked the HU up online hair loss is one of the effects that could happen. I was curious how often it actually happens & to what extent.

I also keep a running list of questions. I use wegovy for weight loss & already deal with nausea on the first couple days of each week. I also already deal with fatigue as one of my ET symptoms. I'd hate for it to get worse. I work from home so I sometimes have to take a nap during my lunch hour in order to make it thru the day.

I also have shin pain, especially at night in bed. Also bones in big toes ache. Dr says not ET, but I think it is

I was diagnosed with ET in November and was on 500 mg HU twice a day, 7 days a week. My platelets initially were at 692 and are now at 172! My dosage has dropped to 500 mg twice a day, 4 days a week and we shall see how I'm doing at my blood draw next Tuesday. Finding the right dosage is trial and error. I have experienced no noticeable side effects. I'm 69 years old and considered high risk due to my age. I'd recommend not worrying about the side effects as, obviously from the comments, we all react differently.

Because my platelet count was 600/700 and I'm 69, my oncologist started me on HU in October 2023. For a month I took 1 500mg capsule a week.

Since that didn't lower the platelet count, I'm now taking 1 500mg capsule 3 times a week.

I'm glad I started HU at a low dose -- that could be why I've had no problems at all with it.

Hydrea does not cause hair loss in the low doses most of us take...it has been an effective drug for over 60 years. In much higher dosages it can have side effects, but so can aspirin and cough medicine. Just follow the instructions ( Take with a meal, drink LOTS of water, and avoid prolonged sun exposure). The very high risk of a pulmonary embolism or a stroke without the medication is so much worse.

My fingernails tend to splinter more and break Don't know if HU, ET or old age????