Just recently diagnosed myself, at 67, and still wrapping my brain around this. Also new to this forum, so my first post is in some other thread but it is within the Essential Thrombocythemia threads. I too am concerned about the side effects of Hydroxyurea, as well as untreated ET. I did not know that hair loss was one of the side effects.
Generally speaking, rosemary is helpful for hair growth. The medication that is often mentioned for hair loss is Minoxidil. Let us know what you learn.