Natural eggshell membrane,
does it really help with Improvement of knee-joint pain, stiffness, and function?
research showsA 2024 meta-analysis reported small improvements in total WOMAC and pain for knee osteoarthritis. However, ingredient-company funding, employment, or consulting recurs across the main RCTs, and the prespecified primary pain endpoint was negative in one study. Independent replication is limited, so the grade is C.
ads claimAdvertising uses 'cartilage regeneration,' 'joint improvement in 7 days,' and combined collagen-hyaluronic-acid language. Clinical evidence concerns self-reported pain, stiffness, and function with specific formulations; it does not demonstrate cartilage regeneration.
Useful facts when choosing a product
- Formulations and doses differ: NEM® 500 mg/day, water-soluble BiovaFlex® 450 mg/day, and other membrane at 300 mg/day.
- Main endpoints are WOMAC, KOOS, NRS, and 6-minute walk.
- Eggshell membrane differs from chicken sternal cartilage collagen and eggshell calcium.
- Safety in people with egg allergy needs separate consideration.
Chamgap Semantic Classification Code
Candidate index · review held
S.natural-eggshell-membrane.UNK.knee-joint-pain-stiffness-and-function.improve.placeboSupplements and nutraceuticals > Natural eggshell membrane > Unknown > knee-joint pain, stiffness, and function > Improvement claim > Placebo
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
Ruff 2009 analyzed 67 participants and reported some WOMAC pain and stiffness signals with 500 mg/day, but authors were affiliated with ESM Technologies and Membrell. Hewlings 2019 tested BiovaFlex 450 mg/day in 88 participants; unnormalized WOMAC, 6-minute walk, and ROM had no between-group differences. Kiers 2021 tested 300 mg/day in 150 participants for 12 weeks; the primary NRS pain endpoint was negative while KOOS pain and daily living were positive. The 2024 meta-analysis pooled these heterogeneous formulations and endpoints.
Why this is classified as C (50)
A small positive RCT meta-analysis exists, but ingredient-company links, formulation heterogeneity, negative or inconsistent primary endpoints, and absent independent replication remain. Boundary rule ②-b therefore supports C with 50 points.
Counterpoint. The pooled estimate leaves open a small average symptom benefit. A preregistered independent multicenter RCT could change the evidence position.
Rejudgment record. New judgment — Small positive RCT meta-analysis, but ingredient-company concentration, formulation heterogeneity, negative prespecified primary endpoints in some trials, and absent independent replication invoke boundary rule ②-b and cap the grade at C
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| García-Muñoz et al. 2024 | Systematic review and meta-analysis | 7 RCTs reviewed; 5 pooled | No external funding | WOMAC, KOOS, and VAS | Total WOMAC -0.34 and pain SMD -0.23; further high-quality RCTs needed. | Key |
| Ruff et al. 2009 OPTION | Randomized, double-blind, placebo-controlled multicenter RCT | 67 in ITT | Author links to ESM Technologies/Membrell | WOMAC pain, stiffness, and function | Some pain and stiffness signals; function and total score were not consistent. | Supportive |
| Hewlings et al. 2019 | Randomized, double-blind, placebo-controlled RCT | 88 participants | Biova LLC funding; consultant and writing support | WOMAC, 6-minute walk, and ROM | Unnormalized analysis showed no between-group difference for the main outcomes. | Limitation |
| Kiers & Bult 2021 | Randomized, double-blind, placebo-controlled RCT | 150 participants | Authors affiliated with Applegg/JLK Nutrition | Primary 6-week NRS pain; KOOS | Primary NRS negative; KOOS pain and daily-living subscales positive. | Key limitation |
Receipt — 4 References
All 4 cited sources were verified for existence at the original page (as of 2026-07-11).
Final verification and publication gate: Codex · Evidence date: 2026-07-11 · Corrections: none
Cite this verdict
[Chamgap] Natural eggshell membrane (NEM) x improvement of knee-joint pain, stiffness, and function — Evidence Grade C·50. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/joint-bone/eggshell-membrane-knee-osteoarthritis/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.