I have a problem with thinning hair, even developing a slight bald spot on top.
My mom has the same thing, but yet her mom has full, fine hair. I've been to docs and they all say its heredity
No matter what shampoo, it doesn't stop, but what helped was when my thyroid tests showed hypothyroidism (I kept saying it, but tests always use to say, "within normal limits", yeah right for who, grrrrrrrrr!
The thyroid med seemed to slow the hair loss rate, but now I have same symptoms and doc won't try increasing my med. claims the new tests show "normal", grrrrrrrr!
I read even if tests show within normal range, one, as an individual can still not be normal range for them, everyone's bod is individual. Damn, GP!!!!!!!!
Well I wish there was some product/shampoo that can stop this, but not even Rogaine (shampoo/treatment) is reliable, I heard if you stop using it, the hair falls out again
I wish I had an answer for you, but I don't.
Have you had any thyroid function tests lately? Maybe there is an underlying abnormal functioning going on, and if so, thyroid meds may help.
Please take care, meanwhile if you hear of something that can help us with thinning hair PLEASE let us know, okay?
Lots of luck, I hope you feel better soon.

Sincerely,
DE