Hi there, Thanks for your query. You need increase in Thyronorm dose as thyroid problem is still under-corrected, as manifested by rough/dry/brittle hair. You may take regular Biotin tablets, which will promote growth of hair. It would be better if you consult a Trichologist who will rule out/detect additional problem of the scalp and hair. Appropriate treatment will restore the hair. Lastly, a fully corrected thyroid deficiency will itself promote regrowth of hair. If you find my response helpful and informative, do not forget an “excellent” (5-star rating) to my answer, to ENCOURAGE ALL doctors- engaged in social service- to render sound advice to the FREE queries. Take care Dr. Rakesh Karanwal