OPI Natural Nail Strengthener is a nail treatment that grants strong nails as well as a long-lasting manicure. The formula is clear and incredibly easy to apply. It takes just a small amount of product to strengthen the nails and also to protect them from discoloration and yellowing of nails from the color application. It creates a protective shield that works under every color, contributing to strong nails and a long-lasting application. Apply it before your nail polish, instead of your regular base coat, to build a durable layer of protection that allows your natural nails to grow strong.