Inclusion Criteria:  ≥ 18 years of age Radiographic evidence of advanced knee osteoarthritis Knee pain Scheduled to undergo a total knee replacement  Exclusion Criteria:  < 18 years of age Unable to provide written consent Known allergy to fish or astaxanthin Pregnant and/or breastfeeding Received a corticosteroid injection within 3 months of initiating treatment with astaxanthin or placebo Currently taking immunosuppressants Patients with known autoimmune etiology for arthritis (e.g. Rheumatoid or Psoriatic arthritis)