To prevent drying and breakage, do take the time to moisturize your hair and scalp with a light moisturizing hair product. Use products that are designed to penetrate the cuticle layer and not cause build-up.
Products DO NOT moisturize hair; water is the only element that increases hydration. Quality products contain molecules that can combine with water help to lock in the water (hydrogen) molecules.
Sincere Product Plug : )
HYDRO-LOCK-Water Soluble Oil Cream (see SHOP) is a soy based cream whose molecules are small enough to penetrate DEEP into the cuticle layer of hair. I highly recommend using the Maximus Sol'ution product line for your hair extension maintenance. The products are environmentally friendly and made of ingredients from only natural and plant sources. It's a very special brand which has been the best hair maintenance line I've ever used. It does exactly what is says it will do.