Effect of Ageratum Conyzoides on Osteoarthritis in an Ageing Adult Population: A Double-Blind Randomized Placebo-Controlled Parallel Study

This randomized, double-blind, placebo-controlled study investigated Ageratum conyzoides (A. conyzoides) for alleviating osteoarthritis symptoms and improving quality of life. Conducted in Australia between 2021 and 2024, the study included 70 adults aged ≥45 years with clinically diagnosed osteoarthritis. Participants consumed 250 mg of pyrrolizidine alkaloid-free A. conyzoides extract or a placebo daily for 12 weeks. Pain and function were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) every three weeks. Secondary measures included pain assessed by the Visual Analogue Scale (VAS), the SF-36 quality-of-life questionnaire, inflammatory markers, and safety parameters. A. conyzoides supplementation resulted in significant reductions in total WOMAC scores at weeks 9 and 12 (p < 0.05) compared to placebo. VAS pain scores were significantly lower at weeks 9 and 12 (p < 0.05). SF-36 scores improved significantly in the pain and role limitations due to physical health domains (p < 0.05). Plasma inflammatory markers IL-6 and IL-8 showed significant reductions compared with placebo (p < 0.05). No between-group differences were observed for adverse events. These findings demonstrate that A. conyzoides supplementation is a safe and effective option for reducing osteoarthritis symptoms, with significant improvements observed in pain, function, and inflammatory markers.