12 Hairstylists Reveal Their Favorite Products For Treating Thinning Hair

"This is a serious game changer. One of my clients (with some of the healthiest long hair I've ever seen) turned me on to Great Lakes Gelatin Collagen Hydrolysate ($25) and, after trying on my own hair and seeing results in as soon as one month, I now swear by it. I add two tablespoons of this magic powder to my morning tea or coffee and it completely dissolves and is tasteless. I've also recommended this to several other clients — the results on their hair (along with skin and nails) have been overwhelmingly positive." — Tina Malhotra, stylist at L'Appartement NYC