Wheat seems to be in a lot of things- bread, pasta, pizza, but it hides in products like shampoo as well. It seems silly to have to check the ingredients of your shampoo, but you may find that wheat proteins are used. So, be cautious of the shampoo you pick, and be sure to read the ingredients on the back! (plus, you'll see how many chemicals are being used)
Happy ingredients reading
-Sema