This product is used with other HIV medications to help control HIV infection. It helps to decrease the amount of HIV in your body so your immune system can work better. This lowers your chance of getting HIV complications (such as new infections, cancer) and improves your quality of life. Both lopinavir and ritonavir belong to a class of drugs known as HIV protease inhibitors. Ritonavir increases ("boosts") the levels of lopinavir. This helps lopinavir work better.