Elvitegravir/cobicistat/emtricitabine/tenofovir, sold under the brand name Stribild, also known as the Quad pill, is a fixed-dose combination antiretroviral medication for the treatment of HIV/AIDS.

Cobicistat increases the effectiveness of the combination by inhibiting the liver and gut wall enzymes that metabolize elvitegravir.

Elvitegravir/cobicistat/emtricitabine/tenofovir gained approval by the U.S. Food and Drug Administration (FDA) in August 2012, for use in adults starting antiretroviral treatment for the first time as part of the fixed dose combination.

Elvitegravir/cobicistat/emtricitabine/tenofovir (Stribild) is priced at 39 percent higher than emtricitabine/rilpivirine/tenofovir (Complera), a three-drug HIV regimen approved a year earlier.

At the time of Complera's approval, there were concerns about the US$20,500 wholesale cost of efavirenz/emtricitabine/tenofovir (Atripla), which is marketed by Gilead and Bristol-Myers Squibb.