The combination of dolutegravir and lamivudine is used alone to treat human immunodeficiency virus (HIV) infection in certain people who have never been treated with any HIV medications before or in certain people who have responded well to their HIV medication regimens and have no history of poor response to their past HIV regimens. Lamivudine is in a class of medications called nucleoside analogue reverse transcriptase inhibitors (NRTIs) and dolutegravir is in a class of medications called integrase strand transfer inhibitors (INSTIs). They work together to decrease the amount of HIV in your blood. Although dolutegravir and lamivudine will not cure HIV, these medications may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking these medications along with practicing safer sex and making other lifestyle changes may decrease the risk of getting or transmitting the HIV virus to other people.