Nimegen is the brand name of an anti-acne treatment that is manufactured by a Singapore-based company. It is considered the equivalent of the American brand Accutane, which has more or less the same ingredients. Nimegen is an isotretinoin, which is used for its ability to destroy cells that divide rapidly among themselves. This helps prevent the spread of acne. Nimegen also contains testosterone, and testosterone insufficiency can cause acne in some people.