Efficacy of natural eggshell membrane for knee osteoarthritis: A randomized, double-blind, placebo-controlled clinical trial

• Natural eggshell membrane was effective in reducing pain and joint function of early-stage knee osteoarthritis patients. • Natural eggshell membrane significantly improved quality of life of early-stage knee osteoarthritis patients. • Natural eggshell membrane significantly changed cartilage oligomeric matrix protein of knee osteoarthritis. • No adverse effect significantly relevant to the natural eggshell membrane was found. Knee osteoarthritis (KOA) is a common degenerative disease in older adults. Natural Eggshell Membrane (NEM) comprises bioactive ingredients known to relieve the symptoms of KOA, such as glycosaminoglycans, and has been shown by preclinical studies to be effective in the treatment of KOA. Participants received either NEM (n = 49) or a placebo product (n = 50). After 12 weeks of NEM intake, the Western Ontario and McMaster Universities Osteoarthritis Index score, visual analog scale pain score, and World Health Organization Quality of Life-BREF score (physical health, social relationship score) significantly improved compared to those in the placebo group ( p < 0.05). However, NEM intake did not significantly change in inflammation and cartilage markers, except for cartilage oligomeric matrix protein. Additionally, no serious adverse events were associated with NEM intake. The 12-week NEM intake was effective and safe for improving pain and joint function in patients with early-stage KOA.