Try bob grasses skin cure friend says it would grow hair on a billiard ball!!

Or there's cornucresine a horses hoof treatment that also is used in hair regrowth..
Buy it from any tack shop etc. It's in a plastic red container a bit like a polish tin.
the stuff is gooey and goes on real easy smells a little aniseedy.
With the thyroid you'd be surprised I have a bitch that is classic hypothyroid,
no outward symptoms only 2 daughters have been diagnosed with Hypo-t one at
a very young age and then the second a year ago borderline hypo-t.
Vet thought I was nuts having bitch tested (I wanted her done as very concerned that 2 in a litter down with
hypo-t, it's not something my breed is routinely tested for either) as she looked so well etc.
Blood test came back as classic a case of hypo-t as you can get.
Vet was very shocked! and wouldn't have believed blood results went with my bitch had she not taken
them herself