Tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, has been used to support/treat symptoms associated with Acquired Immune Deficiency Syndrome (AIDS), particularly in the context of HIV/AIDS-related cachexia (wasting syndrome), anorexia, and nausea. Scientific evidence for its use largely centers on its appetite-stimulating and antiemetic properties rather than direct antiviral effects.

Clinical studies have demonstrated that THC and synthetic cannabinoids like dronabinol (Marinol) can stimulate appetite and promote weight gain in HIV/AIDS patients experiencing significant weight loss. For example, randomized controlled trials have shown that dronabinol is more effective than placebo in increasing food intake and stabilizing weight in these patients. In 1992, the U.S. FDA approved dronabinol specifically for anorexia associated with weight loss in patients with AIDS.

While THC does not treat the underlying HIV infection or immune deficiency, its symptomatic benefits—such as improving appetite, reducing nausea, and enhancing quality of life—are supported by moderate scientific evidence. Adverse effects, including psychoactive symptoms and potential for abuse, are noted. Overall, while not a cure or primary treatment for AIDS, THC is scientifically validated as a supportive therapy for certain AIDS-related symptoms, particularly where first-line treatments are inadequate or poorly tolerated.