I have always had very long thick hair, The last couple years I have experienced hair loss at an alarming rate. I'm not using anything different when it comes to hair products. I do have Thyroid problems but am on medication for it. Also been very stressed.
I was wondering if certain supplements would help. I bought some Biotin and started on that and Vit B6.

These are for hair Folic Acid 800mcg, Biotin 200mcg, Pantothenic Acid 200mg, vitamin E, Zinc 30mg, Manganese 10mg, Choline 1000mg, Inositol 250mg, Para Amino Benzoic Acid 60mg

If your problem is hyperthyroidism I think it means you need to eat
Beetroot, radish, parsley, potatoes, fish, oatmeal and bananas

Avoid iodine

IODINE
(Kelp) (Most essential mineral for thyroid hormone production--deficiency of iodine and/or selenium causes goiter, a swelling of the thyroid gland. A goiter is the body's attempt to increase the production of thyroid hormones from an inadequate supply of nutrients. Replenishing those nutrients will enable the body to resorb the goitrous tissue and allow the thyroid to return to its normal size.)

These foods should be avoided
Cabbage, Brussels sprouts, broccoli, cauliflower, sweet potatoes,

But if your thyroid problem is not hyperthyroidism then you may need to do the opposite.

Some minerals may be helpful too.

Check with a doctor to make sure I have this correct and if it is what your doc would say is correct for you.
I get confused on iodine or not.

My hair was falling out more and more. My daughter suggested that I find a shampoo and conditioner that was very low in alcohol. I did, and now hardly any falls out, amazing (Bed Head, TIGI). NOhelp4you has provided an excellent list of supplements. Lecithin causes hair and nails to grow faster, this may help too.