Interleukin-6 (IL-6)

Interleukin-6, or IL-6, is a cytokine released by immune cells, muscle and fat that drives the acute inflammatory response and signals the liver to make inflammatory proteins.

When tissue is injured or infected, macrophages release IL-6 within hours; it travels to the liver and triggers production of C-reactive protein and other acute-phase proteins, raises body temperature and helps activate B and T cells. IL-6 also rises during exercise, released by working muscle, where it appears to have metabolic rather than inflammatory effects, which shows that the same cytokine can carry different meanings depending on context. Persistently high IL-6 is a feature of rheumatoid arthritis, some cancers and severe infections, and approved antibody drugs block its receptor.

IL-6 is one of the most common readouts in laboratory studies of cannabinoids, where reductions in cultured cells or rodents are frequently reported. A lower IL-6 level in a dish is a mechanistic observation, not a clinical result, and human data on CBD and IL-6 remain limited.