This is a fast-acting self-tanning product from the St. Tropez brand. Within one hour, the self-tan produces glowing results, making it ideal for those speedy, last-minute applications. How deep the tan goes depends on how long the user applies the mousse for. For example, while one hour results in a light shade, three hours leads to a deeper tan. As the mousse is lightweight, users don't feel sticky after applying it.