This study evaluate the efficacy and safety of Dry Extract of Curcuma Longa complexed with phosphatidilcholine (Motore®) Compared to Ibuprofen (Alivium® ) in the treatment of adults with knee osteoarthritis. The study population will consist in participants of both sexes, aged between 40 and 80 years old with a clinical diagnosis of knee osteoarthritis (tibiofemoral joint) based on clinical and radiological criteria (Grades 2 and 3 Kellgren and Lawrence) and who had osteoarthritis symptoms in the last six (06) months preceding the start of the study. They will be randomly allocated to one of two treatment groups , and treatment group 01 will be the dried extract of Curcuma longa complexed with phosphatidylcholine (Motore®), and treatment group 02 will ibuprofen (Alivium®).