Actress Cheryl Ladd has learned to love thickening shampoo, and you can, too, as you get older. “As I’ve gotten older, my thyroid is less active, and when your thyroid goes, your hair gets thinner and thinner,” she said. “I used to have this luscious head of hair, and it’s normal to lose some of it, so I’m babying it a lot now with special hair shampoos.”