Efficacy of eggshell membrane in osteoarthritis

INTERVENTION: For a period of 12 weeks one group receives a daily capsule containing eggshell membrane, and the other group daily receives a placebo capsule. CONDITION: Osteoarthritis ; ; PRIMARY OUTCOME: Main study endpoint includes assessment of self‐reported pain (0‐10) on a Numerical Rating Scale (NRS pain) after 6 weeks SECONDARY OUTCOME: Secondary endpoints include assessment of self‐reported pain (0‐10) on a Numerical Rating Scale (NRS pain) after 12 weeks, as well as self‐reported stiffness and function/health through Knee injury and Osteoarthritis Outcome Scores (KOOS) on days 42 and 84. INCLUSION CRITERIA: • Age between 40‐75 • NRS pain of 3 or more • Diagnosed with osteoarthritis of the knee (confirmed by Health Care Professional) • Able to understand, read, and write Dutch • Daily access to e‐mail and internet • Non‐smoking • Signed informed consent • Willing to comply with study procedures