Formulated with keratin, nail strengtheners are known to rebuild nails ... Formulated with biotin, calcium, and vitamins A, C, and E, OPI also has the "Tri-Flex Technology" that helps to reinforce ...

After a few weeks of using this nail strengthener, I noticed my nails were ... “Apply a treatment base coat. I’d recommend OPI’s Repair Mode, £29.90, a bond-building base designed to ...