Quick answer: yes, for most dogs, joint supplements made for dogs are safe when given at the amount on the label. The PDSA says there are no major side effects and that they can be given safely over a long time. The most common problem is a mild stomach upset in the first few days. The real risks are allergies (many contain shellfish, chicken or fish), a dog eating a whole tub, human supplements that contain ingredients unsafe for dogs, and dogs with health conditions or medication that need a vet's view first. If you want a supplement with clear labelling, we'd recommend MedPaw Hip & Joint Chews: the main amounts per chew and the allergens are on the label, and if it doesn't suit your dog you have 60 days to get your money back.
Transparency note: this page is written by MedPaw, which makes a joint supplement. Sources are linked so you can check them. Checked 9 October 2026.
Are joint supplements safe for dogs?
The PDSA says "There are no major side effects associated with joint supplements" and that they are "safe to use alongside other common arthritis medicines such as anti-inflammatories and pain relief medicines." That matches the dog studies we cite below, where side effects were few and mild.
Two caveats. First, dog joint supplements are sold as complementary feeds, not medicines, so they don't go through the testing a prescription drug does, and quality and labelling vary. Our guide to reading supplement labels helps. Second, "safe" isn't the same as "works": a 2022 review of 72 trials found the clearest benefit for omega-3, while glucosamine and chondroitin did not relieve pain (Barbeau-Grégoire et al., 2022).
Side effects, ingredient by ingredient
Possible side effects of common joint supplement ingredients
| Ingredient | Possible side effects | Take care if your dog... |
|---|---|---|
| Glucosamine and chondroitin | Mild stomach upset is possible. A 30-day dog study found only minor, not clinically significant blood changes (ASPCApro) | Has a shellfish allergy (glucosamine is often made from crustacean shells) |
| Green-lipped mussel | Stomach upset in some dogs | Has a shellfish or seafood allergy |
| Omega-3 fish or krill oil | Diarrhoea, extra calories; high amounts can lower vitamin E (Lenox and Bauer, summarised by dvm360) | Is overweight, is due an operation, or has a fish allergy |
| Boswellia | Brief diarrhoea or wind in a few dogs in one study (Reichling et al., 2004) | Is pregnant or feeding puppies (some brands advise against it) |
| UC-II collagen | No adverse effects reported in the dog trials reviewed by Gencoglu et al. (2020) | Has a chicken allergy (UC-II usually comes from chicken) |
| Brewer's yeast, oats and other fillers | Itching or stomach upset in sensitive dogs | Has a known food allergy or gluten sensitivity |
Most tummy upsets settle within a few days. Giving the supplement with a meal, or starting with half the amount for a few days, often helps. If it doesn't settle, stop and speak to your vet. Brand-specific guides: YuMOVE, Antinol, Seraquin and Nutripaw.
When to stop and call your vet
- vomiting or diarrhoea that lasts more than 24 hours, or blood in either
- facial swelling, hives, intense itching or difficulty breathing (an emergency)
- yellow gums or eyes, severe tiredness or a swollen belly
- your dog has eaten far more than the label amount, such as a whole tub
- stiffness or limping that is getting worse, not better: that needs a vet, not a different supplement
Dogs that need a vet check first
Ask your vet before starting any joint supplement if your dog:
- is pregnant, feeding puppies or still growing
- has kidney, liver or heart disease, diabetes, or a sensitive stomach
- takes any medication, including pain relief such as Metacam or Librela, or blood thinners
- is due an operation
- has a food allergy
Supplements and prescribed pain relief are often used together, but your vet should know about everything your dog takes. See joint supplements vs prescription medicines.
What if my dog eats the whole tub?
Flavoured chews are tempting, and dogs do break into tubs. A big overdose can make a dog seriously ill: ASPCApro describes a case of liver failure after a joint supplement overdose, linked to high manganese levels. If your dog has eaten much more than the label amount, call your vet straight away with the packaging to hand. Keep supplements in a closed cupboard, out of reach.
Don't use human joint supplements
Human products are dosed for people and some contain ingredients that are dangerous to dogs, such as the sweetener xylitol, or added painkillers. Read are human joint supplements safe for dogs? and, if you're buying online, how to buy dog supplements safely.
How to start a joint supplement safely
- Check the ingredients against your dog's allergies.
- Start one new product at a time, so you know what caused any upset.
- Give it with food and follow the label amount. More isn't better.
- Swap rather than stack: don't give two joint supplements at once unless your vet says so.
- Give it six to eight weeks, keeping a weekly note of how your dog moves. See how long joint supplements take to work.
How MedPaw fits
MedPaw Hip & Joint Chews: what's in each chew
| Main amounts per chew | MSM 185mg, glucosamine 170mg, chondroitin 70mg, green-lipped mussel 70mg, Boswellia 30mg, plus hyaluronic acid |
| Vitamins and minerals | Vitamin C 33mg, vitamin E 24 IU, zinc 3mg |
| Contains | Mollusc (green-lipped mussel) and gluten (brewer's yeast) |
| Format | Soft chicken and bacon flavour chew |
| Guarantee | 60 days from delivery, for any reason; email us, nothing to send back |
Like any supplement, MedPaw can upset a sensitive stomach, and it is not suitable for dogs with a shellfish allergy. It's a complementary feed, not a medicine or a painkiller.
Our recommendation: if your dog has no shellfish allergy and your vet is happy, MedPaw is an easy, clearly labelled place to start: one soft chew most dogs take like a treat, all six key joint actives, and 60 days to see how your dog gets on. If it doesn't suit, email us and we'll refund you. Try MedPaw Hip & Joint Chews.
Choosing for an older dog? Read the best joint supplements for senior dogs.
Are joint supplements safe for dogs?
For most dogs, yes, when they're made for dogs and given at the label amount. The PDSA says there are no major side effects and that they can be given safely long term. Check with your vet first if your dog has allergies, a health condition or takes medication.
What are the side effects of joint supplements for dogs?
The most common are mild and temporary: loose stools, wind or occasional vomiting in the first few days. Allergic reactions are possible, especially in dogs allergic to shellfish, chicken or fish, depending on the ingredients.
Can joint supplements cause diarrhoea in dogs?
Yes, sometimes, usually when starting. Giving the supplement with food or starting at half the amount for a few days often helps. If diarrhoea lasts more than 24 hours or contains blood, stop and call your vet.
Can I give joint supplements with Metacam or Librela?
The PDSA says joint supplements are safe to use alongside common arthritis medicines such as anti-inflammatories and pain relief. Always tell your vet what your dog is taking so they can advise.
Can dogs take joint supplements long term?
Yes. The PDSA says they can be given very safely over a long period. Review with your vet at your dog's regular check-ups, and stop if you've seen no difference after a fair trial.
Is MedPaw safe for my dog?
MedPaw is not suitable for dogs with a shellfish allergy, as it contains green-lipped mussel. It also contains gluten from brewer's yeast. Ask your vet first if your dog has a health condition or takes medication.
