What is Kerassentials? And Does It Work? Kerassentials is an advanced nail and skin health support formula that is created by using natural ingredients that can aid in treating toenail fungus and toenail infections. The formula is designed in a way that it can eliminate every type of toenail fungus from your nails along with restricting their mutation to your cuticle. The formula, along with treating nail fungus, also enhances your nail and skin health. Kerassentials are in the form of liquid that you need to apply to your nails daily without fail.