Piz-zaz Hair Thickener Keratin Fibers Reviews I love this stuff. i am a female with very thin hair and this covers the light spots and stays all day. i can't be without it now. Thanks to piz zaz I am a breast cancer "survivor". Lost my hair due to Chemo and medication. Hair came back thin and whispy. Piz zaz fills in the thin areas. GREAT PRODUCT and the color match is perfect for me. Thank You Piz-zaz! I really like the PIZ ZAZ, It looks very natural and gives me confidence in my hair loss. I even bought 6 more bottles, did not want to run out. The Magic of Piz-zaz and How It Works: Like natural hair, Piz-zaz Hair Building Fibers are made of organic keratin proteins. Simply shake on and spray. Once applied to the scalp, the fibers are charged by static electricity that allows the Piz-zaz fibers to bind to your own hair fibers naturally. Piz-zaz will hold and stay in place all day and through the night.