Cuccio Naturale Forte Horsetail Grass Nail Strengthener is guaranteed to help grow stronger longer healthier natural nails in 2 to 3 weeks. Natural botanical horsetail grass gives the perfect amount of nail flexibility which prevents the problems of cracking splitting. The active botanicals create a durable and protective bond with the natural nail surface.Made without formaldahyde or toluene which are chemicals that harden the nails but cause them to crack and become brittle!