Pet supplements / active ingredient
UC-II collagen.
Chicken cartilage collagen processed gently enough to keep its original structure, which is what the trials tested. It is taken in tiny daily amounts, around 40 mg, so it is easy to miss on a label next to ingredients dosed in hundreds of milligrams.
What the labels disclose
Nothing we score carries this as its primary active.
That is a finding, not a gap in our coverage. We only score a product when we can verify its label, and this active is one we grade without it heading up a product we have been able to capture. Where it does appear, it is usually one name inside a blend, which is the case where the amount is least likely to be disclosed.
The evidence
What the published record supports, claim by claim.
Multiple species-specific canine RCTs report reduced pain and improved force-plate-measured limb function, in several cases outperforming glucosamine + chondroitin; body of evidence is still modest and partly industry-linked.
Sources: Gupta 2012 UC-II vs glucosamine/chondroitin, ground force plate, J Anim Physiol Anim Nutr; D'Altilio 2007 UC-II singly or combined in arthritic dogs, Toxicol Mech Methods
The longer read
What this active does and does not show.
Several canine trials report reduced pain and better force-plate-measured limb function for undenatured type II collagen, in some cases outperforming glucosamine and chondroitin head to head. The body of work is modest and partly industry-linked, which is why we grade it with support rather than well supported.
The reason this page may show few or no products is not an oversight. We score what we can verify, and this active rarely appears as the headline ingredient on the products we have been able to capture. If you find it at all, it is usually one name inside a blend, which is exactly the case where the amount is least likely to be disclosed.
Evidence grades are PetScored's reading of the published record under our supplements methodology, not veterinary advice and not a claim about what will happen to your animal. Every grade is pinned to a named primary source; where the evidence is thin or contested, we say so rather than rounding it up. If your dog or cat is stiff, sore, or slowing down, that is a conversation with your vet, not a shopping decision.