Joint supplements for older dogs: what works and what to expect
Updated 4 November 2026. 5 minute read.
Short answer: Green-lipped mussel and omega-3 fish oil have the strongest evidence. Glucosamine is popular but the evidence is mixed. Give any joint supplement for six to eight weeks before you decide.
Which ingredients have the best evidence
Omega-3 fats from fish (EPA and DHA) have the strongest research behind them for dog joints. Green-lipped mussel, a shellfish from New Zealand, contains omega-3 plus other joint compounds and has several small studies showing dogs moving more comfortably.
Glucosamine and chondroitin are the best-known names. Studies in dogs are mixed: some show a benefit, others don't. They're safe and widely used, so many owners combine them with mussel or fish oil.
How long before you see a difference
Joint supplements work slowly. Give one every day for six to eight weeks, then judge it. Signs it's helping: getting up more easily, less stiffness at the start of walks, more willing to jump into the car.
If you see no change after eight weeks, try a different main ingredient rather than a higher dose of the same one.
Chews, powder or liquid
Chews are easiest for most dogs. Powder suits fussy eaters because it's unflavoured and mixes into food. Liquid is easiest to measure for big dogs.
When to see a vet instead
A supplement supports healthy joints. It doesn't treat pain. Limping, yelping, swollen joints or stiffness that comes on suddenly all need a vet. Keeping your dog lean helps joints more than any supplement.
Common questions
At what age should a dog start a joint supplement?
Most owners start around seven, or earlier for large breeds and very active dogs. There's no harm starting earlier.
Can I give a joint supplement with my dog's vet medicine?
Usually yes, but tell your vet what you're giving, especially if your dog takes anti-inflammatories or blood thinners.
Is green-lipped mussel safe for dogs with a shellfish allergy?
No. Avoid it and choose a fish oil or glucosamine product instead.
This page is general advice, not a diagnosis. If you're worried about your dog, speak to your vet.