(Oil-Free) Contains the active ingredient BIOTINE which is a very special product. The Natural Moisturizing Factors between the layers of the nail were copied in this product. These Moisturizing Factors keep the nails supple. The main reason why many people have hard and brittle nails is because their nails lack these Moisturizing Factors.Application once a week is all that is needed to sufficiently build strong beautiful nails.TRIND Nail Balsam is guaranteed to be oil free. This is very important because after applying TRIND Nail Balsam, you may use nail polish or TRIND Natural Nail Repair strengthener immediately afterwards!