Gel manicures are known for shining brighter and lasting longer than aregular manicure, lasting as long as two weeks without a crack. But can the special process that gives your nails their patent leather gleam also be harmful to your health? The gel manicure process requires four or five coats of polish, with each layer followed by a finish under a UV light, a similar light to those used in tanning beds, only far weaker. Safer Mani-Pedis: Steps You Can Take Some dermatologists warn the typical 5-10-minute exposure to the light during a gel manicure could be harmful.  A 2009 article in the Archives of Dermatology concluded that “further investigation”.