Many of us spend a fortune on hair care products to get a thick, shiny mane. Yet most people are unhappy with their hair. From frizzy strands to thinning locks, it seems like no matter what you do, you can’t get that perfect hair. Those same products that are supposed to give you luscious locks may be behind your hair woes. If you have dry, brittle hair, or your strands are falling out more than usual, your shampoo might be…