OPI Nail Envy 15ml - Nail Strengthener for Sensitive and Peeling Nails. For sensitive, peeling nails in need of strengthening and repair. This nail strengthener protects nails against peeling with antioxidant Vitamin E and Kui Nut Oil, plus soothes sensitivity with Aloe Vera. Strength is beauty and OPI delivers strength with its range of Nail Envy natural nail strengtheners. OPI has developed a different formula to meet your individual needs. The concentrated calcium in this nail strengthener protects peeling nails by strengthening and thickening the nail. This nail strengthener is an ideal peeling nails treatment due to its antioxidant rich, Formaldehyde-free formula.