Metanail Serum Pro is a topical serum consisting of 20 nutrients that help to strengthen, rejuvenate, and improve nail health. It helps to combat brittle nails and toenail fungus also known as onychomycosis. This serum contains 100% natural ingredients. Moreover, the Metanail Serum Pro is manufactured in an FDA-approved facility while following all good manufacturing practices so it is safe to say that the product is free of any contaminants and safe.