Feeding him some yellow and orange color veggies help iguanas shed better. They contain beta-carotene and vitamin A necessary for healthy and vibrant skin. Winter squash seems to be the best to use and contain a lot of roughage and carbohydrate, that they also really need. Mine loves butternut squash, especially if I microwave it a little after I grate it. You can use carrots and yam, too, but carrots is kindda high in calcium oxalate and yam also has a lot calcium oxalate and it is also not as nutritious as the squash. The carbohydrate provides a lot of fuel for the metabolisms, and hence, I think, helps with the hormonal balance.