Benefits
Knee joint pain and stiffness, studied in adults with knee osteoarthritis
In an 8-week placebo-controlled trial in 67 adults with knee osteoarthritis, 500 mg a day eased pain and stiffness from day 10, but overall WOMAC and function scores did not differ significantly from placebo. A 12-week trial of 300 mg a day in 150 adults found no difference in its main pain score, though a secondary knee pain score improved. The 8-week trial was sponsored by the maker.
Pooled trial results for knee comfort
A meta-analysis of 5 placebo-controlled trials in knee osteoarthritis found small improvements: total WOMAC score SMD -0.34 (95% CI -0.56 to -0.13) and pain SMD -0.23 (95% CI -0.42 to -0.04). In a network meta-analysis of seven supplements, eggshell membrane scored better than placebo on WOMAC pain and stiffness, but the differences were not statistically significant.
Exercise-related joint discomfort in postmenopausal women
In a 2-week placebo-controlled trial in 60 healthy postmenopausal women, 500 mg a day sped recovery from exercise-related joint pain and stiffness, though pain right after exercise did not differ. Its main outcome, the cartilage-breakdown marker CTX-II, fell compared with placebo. Two authors worked for the maker and another was a paid consultant.
What is in it, and at what dose
Eggshell membrane is mainly collagen type I and also contains chondroitin sulfate, dermatan sulfate, hyaluronic acid and glucosamine. At 500 mg a day the amount of each compound is small, far less than the gram doses used for glucosamine and chondroitin, and no cited study showed that this mixture works better than those compounds taken separately.
Mechanism of action
Cartilage and joint-fluid building blocks
Eggshell membrane contains collagen and glycosaminoglycans such as chondroitin sulfate and hyaluronic acid, which are building blocks of cartilage and joint fluid. At 500 mg a day the amounts are small, and no cited human study measured absorption or cartilage, so this is a proposed explanation.
Lower cartilage-breakdown marker after exercise
In healthy women doing a short exercise program, eggshell membrane lowered CTX-II, a marker of type II collagen breakdown, compared with placebo after 1 and 2 weeks. A marker change does not show that joints are protected.
Clinical trials
Randomized, double-blind, placebo-controlled multicentre trial of eggshell membrane (NEM, 500 mg a day) versus placebo for 8 weeks (Ruff et al. 2009, Clin Rheumatol)
67 adults with knee osteoarthritis (34 NEM, 33 placebo).
Response rates for pain and stiffness were significantly better than placebo at days 10, 30 and 60, but overall WOMAC and function scores did not differ significantly, though they trended toward improvement. No serious adverse events occurred. The study was funded by the maker, ESM Technologies, which employed the lead author.
Randomized, double-blind, placebo-controlled trial of eggshell membrane (NEM, 500 mg a day) for 2 weeks during an exercise program (Ruff et al. 2018, Clin Interv Aging)
60 healthy postmenopausal women.
CTX-II, a cartilage-breakdown marker and the main outcome, fell versus placebo at 1 and 2 weeks. Recovery pain and stiffness improved faster, but pain right after exercise did not differ. No serious adverse events. Two authors were employees of the maker and another was a paid consultant.
Randomized, double-blind, placebo-controlled trial of 300 mg a day of eggshell membrane for 12 weeks (Kiers et al. 2021, J Med Food)
150 adults aged 40 to 75 with knee osteoarthritis.
The main outcome, pain on a numerical rating scale at 6 weeks, fell at about the same rate in both groups. On the secondary KOOS questionnaire, pain and daily-life function scores improved more with eggshell membrane from week 1.