Benefits
Joint comfort and stiffness
In one randomized, double-blind, placebo-controlled trial, 88 adults with knee osteoarthritis (44 on eggshell membrane, 44 on placebo) reported improved walking distance and walking ability and less stiffness compared with placebo, with changes appearing by day 5 and holding through 12 weeks. The researchers reported the greatest benefit in the most severely affected people, so these results come from patients under care for a joint disease and should not be assumed to apply to a healthy person. Osteoarthritis is a medical condition to manage with a doctor.
Walking and mobility (studied only in knee osteoarthritis)
The one published trial measured walking ability and stiffness in adults with knee osteoarthritis. It did not test exercise recovery, athletic performance, or flexibility in healthy people, so there is no evidence behind those uses.
Connective-tissue support
It supplies collagen, elastin, and hyaluronic acid, which are also components of cartilage and joint tissue. Sharing ingredients with cartilage is not the same as rebuilding it, and no cited study has shown that swallowing eggshell membrane changes cartilage in people.
Mechanism of action
Connective-tissue substrate
Eggshell membrane supplies collagen, elastin, and glycosaminoglycans. The proposed idea is that these give the body raw material for cartilage and connective tissue, but that is a theory: the single human trial measured symptoms such as walking ability and stiffness, not cartilage.
Proposed effect on inflammatory signals
Some researchers have suggested eggshell membrane influences inflammatory signals in the joint. The trial cited on this page did not measure inflammatory markers, so this is an unconfirmed explanation rather than a demonstrated effect.
Clinical trials
Randomized, double-blind, placebo-controlled trial of Biovaflex water-soluble eggshell membrane in 88 adults (44 supplement, 44 placebo) over 12 weeks. This is the only published trial of this branded ingredient. (Hewlings et al. 2019, Journal of Medicinal Food)
Adults diagnosed with knee osteoarthritis, not healthy adults.
Participants taking eggshell membrane reported better walking distance and walking ability and less stiffness than placebo, with differences appearing by day 5 and maintained through 12 weeks. The authors noted the largest improvements in the most severely affected participants. Limitations: a single trial, 88 people, and everyone enrolled had a diagnosed joint disease, so the findings cannot be assumed to apply to healthy people.