Instgra (Dolutegravir) is used with other medications to treat human immunodeficiency virus (HIV) infection. Dolutegravir is in a class of medications called HIV integrase inhibitors. It works by decreasing the amount of HIV in your blood and increasing the number of immune cells that help fight infections in your body. Although dolutegravir does not cure HIV, using it along with other medications may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer.