Eggshell Membrane for Dogs With Arthritis: Evidence

Eggshell membrane has been tested in randomized canine joint studies, and several trials report improvement in selected mobility or pain measures. The evidence is promising but still limited: study sizes are modest, results are not uniform across every outcome, and newer positive trials often test eggshell membrane as part of a multi-ingredient formula.

That means evidence for a defined eggshell-membrane preparation should not be generalized to every joint supplement that contains the ingredient.

Key takeaways

Placebo-controlled canine studies exist for eggshell membrane.
A 51-dog study of NEM® found less pain than placebo at some time points (owner score at 1 week, veterinarian score at 6 weeks), but not consistently across outcomes and times.
A smaller 2019 OA pilot found a significant LOAD difference at day 84 but not the same pattern on CBPI.
A 2025 positive study used eggshell membrane with krill, astaxanthin, hyaluronic acid and Boswellia; it cannot isolate eggshell membrane.
Biomarker changes should not be treated as equivalent to clinical mobility improvement.

What is eggshell membrane?

The thin membrane lining an eggshell contains proteins and connective-tissue components. Commercial joint ingredients may use processed eggshell membrane preparations.

The evidence should be interpreted at the level of the specific preparation, not the ingredient family in the abstract.

What controlled studies found

A multicenter randomized double-blind placebo-controlled study enrolled 51 dogs with suboptimal joint function. Dogs received NEM® eggshell membrane at about 6 mg per lb of body weight (150 mg per 25 lb; the paper reports this as about 13.5 mg/kg) or placebo once daily for six weeks. Owners scored their dogs with the Canine Brief Pain Inventory (CBPI) at 1 and 6 weeks, and veterinarians scored joint pain, mobility and lameness (Veterinary Canine Scoring Assessments, VCSA) at 6 weeks.

Compared with placebo, the eggshell membrane group showed:

less owner-scored pain (CBPI pain) at 1 week (P = 0.010), but the difference was no longer statistically significant at 6 weeks;
less veterinarian-scored joint pain at 6 weeks (P = 0.012);
better owner-scored quality of life at 6 weeks (P = 0.033), after no significant difference at 1 week.

That is a genuine between-group signal on pain for this branded preparation. It is also uneven: owner-scored pain and quality of life were significant at different time points, the veterinary mobility and lameness scores are not reported as significant, and the study was published by researchers from the ingredient’s manufacturer (ESM Technologies).

A 2019 randomized double-masked placebo-controlled pilot enrolled 27 dogs with OA-associated pain and mobility impairment; 22 completed the study. At 12 weeks, LOAD scores were significantly lower in the supplement group than placebo (p = 0.034), while CBPI did not show the same pattern. The authors explicitly described the changes as small and not definitive.

That is an important limitation: a positive result on one mobility scale does not mean every pain or mobility endpoint improved.

Why the 2025 combination study cannot prove an eggshell-membrane effect

A 2025 multicenter randomized placebo-controlled study tested a formula containing:

eggshell membrane;
krill meal with omega-3 fatty acids;
astaxanthin;
hyaluronic acid;
Boswellia serrata extract.

Fifty-two dogs were enrolled and 46 were analyzed (22 supplement, 24 placebo) over 90 days. All five main measures improved over time in the supplement group, while only CBPI pain interference and LOAD improved in the placebo group. The only significant between-group difference was CBPI pain interference (p = 0.009).

This is useful formula-level evidence. It does not allow the result to be attributed to eggshell membrane alone.

Biomarkers are not mobility outcomes

The 2019 pilot also measured inflammatory biomarkers. Small biomarker changes may help generate hypotheses, but they should not be presented as proof that a dog moves better or experiences less pain.

For this article:

biomarker change ≠ clinical improvement

What the evidence does not prove

every eggshell membrane product works;
a multi-ingredient formula effect belongs to eggshell membrane;
biomarker changes establish pain relief;
eggshell membrane replaces standard multimodal OA care.

Dog Supplement Facts evidence status

MIXED — PREPARATION-SPECIFIC

Two small placebo-controlled trials of eggshell membrane alone found some between-group benefit, but not consistently: the manufacturer-run 51-dog NEM® trial on pain at some time points and on quality of life at 6 weeks, and the 22-dog pilot on LOAD only. The newest positive trial tested a combination. Under our rating rules, benefit on some outcomes but not others is mixed evidence. In our ingredient comparison this places eggshell membrane below omega-3, green-lipped mussel and UC-II, which have larger and more consistent canine evidence bases.

What dose was used, and how to check a label

The 51-dog trial gave about 13 mg of eggshell membrane per kg of body weight per day. For a 10 kg (22 lb) dog that is roughly 130 mg a day; for a 30 kg (66 lb) dog, roughly 400 mg. Many multi-ingredient chews list eggshell membrane without an amount, or at much lower amounts. Use the joint supplement dose checker to compare a label with the study dose, and prefer products that state the membrane amount in mg.

Compare products that list eggshell membrane Check a label against the study dose Check your dog's body condition score Not sure this is the right topic? Use the symptom checker

In our comparison: products that list eggshell membrane

3 of the 205 dog joint & mobility products we compared list eggshell membrane (1%). None of them is among the 20 most popular products, and their median popularity rank is #151 of 188 ranked products. Our ingredient-level evidence rating for eggshell membrane: mixed.

Product-level ratings, which look at the whole formula: 3 mixed.

Frequently asked questions

Does eggshell membrane work for dogs with arthritis?

Small placebo-controlled canine trials of specific eggshell membrane preparations report improvement in some mobility or pain measures, but not consistently across all outcomes, and the newest positive trial tested a multi-ingredient formula. The evidence is promising but limited.

How much eggshell membrane was used in the dog study?

The 51-dog NEM® trial used about 150 mg per 25 lb of body weight per day (about 13 mg per kg) for six weeks. Our joint supplement dose checker compares a label's amount with that dose.

Is eggshell membrane the same as eggshell calcium?

No. Eggshell membrane is the thin protein layer lining the shell; eggshell powder or eggshell calcium is ground shell, a mineral source. Only membrane preparations were tested for joint function.

Can I give eggshell membrane with other joint supplements?

Many products already combine it with glucosamine, fish oil or other actives. Because the trials tested specific preparations, check the label amount, avoid doubling up on products, and ask your veterinarian if your dog takes pain medication.

References

Ruff KJ, et al. Effectiveness of NEM® brand eggshell membrane in the treatment of suboptimal joint function in dogs: a multicenter, randomized, double-blind, placebo-controlled study. 2016. PMID 30050844.
Müller C, et al. Placebo-controlled pilot study of the effects of an eggshell membrane-based supplement on mobility and serum biomarkers in dogs with osteoarthritis. Veterinary Journal. 2019;253:105379. PMID 31685140.
Efficacy of a joint supplement containing eggshell membrane among other ingredients to improve the mobility of dogs with osteoarthritis: a multicenter double-blind randomized placebo-controlled study. Frontiers in Veterinary Science. 2025. PMID 40530040.