List of products in the National Drug Code with proprietary name advil liquigels. Ibuprofen is used to help relieve mild to moderate pain. When used with an opioid (such as morphine), it may be used to relieve moderate to severe pain. It is also used to reduce fever. Ibuprofen is known as a nonsteroidal anti-inflammatory drug (NSAID). It works by blocking your body's production of certain natural substances that cause inflammation. This effect helps to decrease swelling, pain, or fever.