Eggshell membrane in the treatment of pain and stiffness from osteoarthritis of the knee: a randomized, multicenter, double-blind, placebo-controlled clinical study

Ruff KJ, Winkler A, Jackson RW, et al. · Clinical Rheumatology

Against placebo, eggshell membrane reduced WOMAC pain by 15.9% at day 10 (p=0.036), 10.3% at day 30 (p=0.040) and 15.4% at day 60 (p=0.038), and stiffness by 12.8%, 16.8% and 26.6% (p=0.024, 0.009, 0.005). The trial's primary measure, overall WOMAC, did not reach significance at any time point (15.2% at day 10, p=0.059; 15.1% at day 60, p=0.052), nor did function (15.5%, p=0.084; 13.5%, p=0.076). By OMERACT-OARSI criteria 32% of the treatment group responded against 12% on placebo (p=0.023) at 60 days, and about a third of patients in each group reached a 40% pain reduction.

Population

Adults with knee osteoarthritis, USA

Intervention

Natural eggshell membrane (NEM) 500 mg once daily for 8 weeks

Comparator

Placebo

Limitations

Sponsored by ESM Technologies (NEM's maker) with a company author; 8 weeks only. Of 67 randomised, 60 formed the intent-to-treat population and the analyses rest on 21 placebo and 24 treated patients — a 43% dropout against a planned 20%, with the patients lost mid-study having worse baseline WOMAC scores than those who finished. The placebo arm drifted slightly worse rather than better on every subscale, which the authors flag as an absent placebo effect and which supplies much of the between-group difference.