Mobility Support:
eggshell membrane, cartilage repair and more.

How does eggshell membrane work as a complete cartilage matrix, what does type II collagen do in osteoarthritis, and what does the most recent veterinary literature say? The scientific background of Mobility Support in dogs, cats and humans.

By Stefan Veenstra DVM

Osteoarthritis: a structural and inflammatory problem

Osteoarthritis is the most common degenerative joint disease in dogs, cats and humans. It is estimated that 20% of dogs over 1 year of age have clinically relevant osteoarthritis, and in cats over 10 years of age, the prevalence rises to more than 50%. ^[1] The pathophysiology is more complex than traditionally thought: osteoarthritis is not a purely mechanical wear and tear disease but an inflammatory synovial process in which cartilage breakdown, synoviitis, adjustment of the bone under the cartilage and pain modulation occur simultaneously.

Central mediators are matrix metalloproteases (MMPs) that are activated by pro-inflammatory cytokines (IL-1 beta, TNF-alpha) and break down the extracellular cartilage matrix. MMP-1, MMP-3 and MMP-13 degrade collagen type II, aggrecan and other structural glycosaminoglycans. Supplementation with the direct building blocks of the cartilage matrix therefore has two goals: structural recovery through the supply of building materials and inhibition of the degradation cycle through substrate competition. ^[2]

Eggshell membrane: wider than just joints

Eggshell membrane is primarily a joint supplement, but its composition extends beyond that. It contains collagen type I, V and X, hyaluronic acid, glycosaminoglycans and growth factors (TGF-beta, IGF-1, FGF) in their natural interrelationship. Collagen type I is also the primary structural fiber in tendons, ligaments, and deep fascia. Hyaluronic acid plays a central role in the gliding function between fascial layers. TGF-beta and FGF activate fibroblasts for new collagen synthesis in damaged connective tissue. ^[1]

This makes ESM not only relevant for osteoarthritis but also for recovery from tendon injuries, ligament damage and musculoskeletal overload. Thomas Myers (Anatomy Trains) and Rikke Schultz DVM (Equine and Canine Myofascial Kinetic Lines, Fascialines.com) describe how myofascial power transmission lines in dogs and horses function via the same ECM architecture as in humans. ^[3] A side note: fascia also contains significant collagen type III and VI that ESM does not provide. ESM is therefore a useful supporter of connective tissue regeneration, but not a complete fascial ECM replacement. As a supplement to the Joint Protocol and Surgery Recovery Package, it can be used in a wide range of applications.

Eggshell membrane: a complete cartilage matrix in one ingredient

The eggshell membrane is a thin fibrillar mesh membrane that lines the inside of the eggshell and protects the developing germ. It consists of more than 90% protein and naturally contains a remarkably wide collection of joint building blocks: collagen types I, V and X, multi-molecular weight hyaluronic acid, glucosamine, chondroitin sulfate, dermatane and keratin sulfates, elastin and biologically active growth factors including IGF-1 and TGF-beta. ^[3]

The distinguishing feature of eggshell membrane from individual supplements is that all these components are present in their natural interrelationship, as they also occur in the extracellular cartilage matrix. IGF-1 and TGF-beta are growth factors that directly stimulate chondrocyte proliferation and collagen synthesis, components that are lacking in isolated glucosamine or chondroitin supplements. ^[3]

A systematic review and meta-analysis in Nutrients (García-Muñoz et al., 2024) analyzed seven RCTs for eggshell membrane in knee osteoarthritis in humans and found significant pain reduction and function improvement (WOMAC total score effect size -0.34; p significant improvement). The translatability of this mechanism to the veterinary context is direct: the human and canine osteoarthritis mechanism proceeds via identical cellular pathways. ^[6]

Why liposomal preparation is essential

This is the component that distinguishes most joint supplements on the market from Mobility Support. Glucosamine and chondroitin sulfate are the best-researched joint supplements, but their bioavailability after oral ingestion is limited. Glucosamine has an oral availability of 26% in dogs after hydrolysis in the intestine, with significant variation. Chondroitin sulfate is a large polysaccharide molecule of 5-70 kDa that is moderately absorbed, and in which a large part is broken down in the gastrointestinal tract before reaching the target tissues. This explains why many standard glucosamine/chondroitin supplements show disappointing results in clinical studies: the product does not reach the cartilage matrix sufficiently.

Liposomal encapsulation fundamentally addresses this problem. Phospholipid vesicles envelop the active substances and protect them from degradation in the gastrointestinal tract. Uptake is via endocytosis, independent of the passive diffusion route that hardly works for large polysaccharides. This significantly increases the systemic availability of glucosamine, chondroitin, and collagen. Liposomal preparations actually reach the synovial membrane, cartilage and periarticular tissues in therapeutically relevant concentrations. Without liposomal preparation, a high dosage on the label but a limited effect is the reality in practice with most joint supplements.

The additional components of Mobility Support in detail

Collagen type II: the structural backbone of cartilage

Collagen type II forms the fibrillar architecture of hyaline cartilage and is the most abundant protein in articular cartilage. In osteoarthritis, MMP-13 (collagenase-3) degrades collagen type II as a primary substrate, leading to progressive loss of cartilage structure and function. Hydrolyzed collagen type II is absorbed as dipeptides and tripeptides after intestinal absorption and used by chondrocytes as a precursor for new collagen synthesis, but also directly modulates the immune response via oral tolerance induction. ^[7]

Glucosamine: precursor of glycosaminoglycans

Glucosamine is a hexosamine used by chondrocytes as a direct building block for the production of glycosaminoglycans (GAGs), including hyaluronic acid, chondroitin sulphate and keratin sulphate. These GAGs form the hydrophilic matrix of the cartilage that determines water retention and compression resistance. Without adequate glucosamine availability, GAG production in arthrotic cartilage decreases further. A 2022 meta-analysis (Nutraceuticals for osteoarthritis, IJMS) differentiated the evidence: glucosamine has modest but demonstrable effects on subjective pain but more limited effect on structural cartilage changes, making it best usable as part of a more complete joint supplement. ^[8]

Chondroitin Sulfate: Hydration, Resilience, and MMP Inhibition

Chondroitin sulfate is the most abundant glycosaminoglycan in hyaline cartilage and synovial fluid. It binds water through its negatively charged sulfate groups, which maintains the osmotic pressure in the cartilage that is necessary for compression resistance. Chondroitin sulfate also directly inhibits the activity of MMP-3 and MMP-13, the proteases that break down cartilage collagen and aggrecan in osteoarthritis. In dogs and cats with osteoarthritis, chondroitin sulfate concentrations in the cartilage have been shown to be reduced. ^[2]

Evidence note: Effect on pain versus structure

The systematic review by Lesponne et al. (2022) in IJMS, which analyzed 72 veterinary trials on nutraceuticals in osteoarthritis in dogs and cats, found clear clinical analgesic effectiveness for omega-3 supplements and CBD, and more limited evidence for glucosamine and chondroitin separately for pain management. ^[9] This is a relevant fact that leads us to position Mobility Support as a structural cartilage supporter that is primarily intended for building and maintaining joint architecture, and that works most effectively as part of a broader protocol (Joint Protocol) where omega-3 via Calanus oil and pain and inflammation modulation via PEA Complex and CBD have been supplementally introduced.

This information is educational in nature and based on available scientific literature. The studies mentioned are not always directly veterinary or specific to the formulation described here. This text does not replace a veterinary consultation and does not contain any therapeutic claims.