50 patients with knee primary osteoarthritis were randomly assigned to receive orally administered 180 mg/day curcumin (Theracurmin) or placebo for 8 weeks. The purpose of this trial was to determine the effects of curcumin in patients with knee osteoarthritis via blood biochemistry analyses, VAS pain, Japanese Knee Osteoarthritis Measure, Japanese Orthopedic Association knee scoring system, need for nonsteroidal anti-inflammatory drugs (NSAIDs), and adverse events. The findings revealed similar outcomes between groups at final follow-up, however, fewer patients in the curcumin group required additional NSAID analgesia than in the placebo group.