During the first few years of the AIDS epidemic in the early 1980s, poppers were suspected as being a contributing factor to the disease. Some researchers and many activists in the gay community thought the drug might be the cause of the virus. While it has been proven that poppers do not cause human immunodeficiency virus (HIV), the virus that leads to AIDS, there is substantial research evidence that links it to immune system problems in people with HIV, including increasing the risk for Kaposi's sarcoma (KS), a deadly cancer often found in people in the advanced stages of AIDS.

In a study conducted in the early 1980s, soon after HIV was identified as the cause of AIDS, the Centers for Disease Control (CDC) found that of 87 patients studied with KS, 84 reported regularly using poppers. Although there is no conclusive proof, later studies have...