Iron supplements worked in one month

After a month of taking iron, my iron level normalized and my hair has continued to thicken up in much of the top (to where the barber thinned a section for the first time since ~2006). Not really the left corner and not the crown or back, though all that looks stable now and very little hair comes out in the shower. I do not have celiac. Invasive examination so far hasn’t found anything that would affect hair or absorption.

How long should I wait to see if any regrowth in the problem areas happens?

Always give hair changes 6 months to kick in a new anagen cycle. Then you will know and we should meet then