I also have thyroid issues and agree with all the above. The only thing I have to add is my hair has been very dry. I would recommend you make sure you are meeting your hairs needs ( moisture/protein) based on your hair type. I mean I have to use a rediculously amount of moisture for my short hair
2a canopy with 2b underneath.
Fine hair, low elasticity,
Hair dislikes oil
Live in dry climate