OPI’s gel nail polish is officially called “GelColor Soak-off Gel Lacquer” and in short, a gel manicure is a coat of colored gel that looks deceptively similar to nail polish. It’s a thin brush-on formula, designed for high performance and a glossier finish than regular nail polish. When it comes to the question of “How long do gel nails last?” In fact, an OPI GelColor manicure lasts for up to 3 weeks.