Strengthen & grow. Layers & layers of protection for nails! Nourishes, hydrates, adds thickness & protection. Protein-enriched formula. Salon tested. Dermatologist tested. Sally Hansen creators of the most innovative defense for thin, weak, brittle nails: Thicken Up! Strengthening Nail Thickener. Thicken Up! shields your nails with layers and layers of ultra-dense nail protection. This advanced gel complex fortified with Protein, Trehalose and Retinol penetrates nails to deeply nourish, hydrate and help reinforce. Adds strength to nails to help resist breaking, cracking and splitting. Thicken Up! goes on smoothly and evenly over bare nails. Use alone or as a strengthening base coat under your favorite Sally Hansen nail color. Made in USA.