Medical marijuana

April 2005     View PDF     En español

Immune function

Marijuana and/or its psychoactive ingredient THC have been reported to suppress many immune functions. These include the function of cells important in controlling infections commonly seen among people living with HIV. Marijuana may also increase your risk for certain infections, including herpes and a variety of other bacterial, viral and fungal infections. Some of these infections may result in increased HIV levels. None of this, however, has been clearly documented in HIV-positive people.

Some research suggests that marijuana has no significant effect—good or bad—on the immune system of people living with HIV. Studies from the Multicenter AIDS Cohort Study evaluating outcomes in 1,662 HIV-positive users of psychoactive drugs (marijuana, cocaine, LSD, etc.) found that none of the drugs were linked to a higher rate of HIV disease progression or loss of CD4+ cell counts. Of the men who took part in the study, 89% reported using marijuana in the preceding two years. A recent study, presented in 2000, examined the short-term impact of marijuana, dronabinol or placebo on HIV levels, CD4+ cell count and HIV levels. After twenty-one days, the use of marijuana did not appear to have harmful affects. Much longer-term studies are needed before concluding that marijuana use is either safe or unsafe for people living with HIV, however.