Max Strength Plus is our all-in-one daily porridge with serrapeptase added. It contains everything in Max Strength (glucosamine, chondroitin, MSM and hyaluronic acid, our full Nourish + C multivitamin and mineral blend, omega 3 and 6, and probiotics and prebiotics) plus 75mg of serrapeptase, a natural enzyme originally derived from silkworms. Gluten and wheat free, made in the UK, from around 76p a day for a medium-sized dog.

Who it's for

Max Strength Plus is a good choice if your dog is:

• a working dog: gundogs, herding dogs, search and rescue and more
• a sport or performance dog: agility, flyball, canicross, sled or detection work
• very active or athletic
• older and beginning to slow down or stiffen up
• one you'd like to give joint support and all-round nutrition in a single daily feed
• one you'd like to give serrapeptase alongside joint support and all-round nutrition

Not sure which supplement is right?

• Max Strength Plus: everything in Max Strength, with 75mg serrapeptase added.
• Max Strength: the same porridge without serrapeptase, at a lower price.
• Hip & Joint Dog / Hip & Joint Dog PLUS: concentrated joint powders you add to your dog's usual food, with higher daily amounts of glucosamine and MSM.

How to feed it and what it costs

Mix with warm water to make a porridge, stir into wet food, or sprinkle over wet or dry food. Recommended from 9 to 12 months old upwards.

Optional loading phase: double the daily amount for the first 7 days when starting Max Strength Plus.

Cost per day for a medium dog: 1.2kg (30 days) £1.05 · 1.8kg (45 days) 93p · 2.4kg (60 days) 91p · 5kg (125 days) 79p · 10kg (250 days) 76p.
Subscribe: 50% off your first month, then 10% off every order, and you'll never run out.

Days' supply is based on the medium-dog amount above, so smaller dogs' tubs last longer and larger dogs' less. A 75ml scoop is included with every order; let us know at checkout if you'd prefer not to receive one with future purchases.

What's in it (per medium-dog daily serving of about 40g)

🌾 Gluten and wheat free. Complements all diets, including raw.

Joint nutrients

Vitamins, minerals, amino acids, omegas and probiotics

Analytical constituents: Protein 15.3%, Fibre 10.3%, Fat 5.7%, Omegas 3 and 6 8.9%, Crude Ash 3.1%.

Frequently asked questions

What's the difference between Max Strength Plus and Max Strength?

They're the same porridge, but Max Strength Plus has 75mg of serrapeptase, a natural enzyme, added.

How is Max Strength Plus different from Hip & Joint Dog PLUS?

Both contain serrapeptase. Max Strength Plus is an all-in-one porridge with joint nutrients, a full multivitamin and mineral blend, omega 3 and 6, and probiotics. Hip & Joint Dog PLUS is a concentrated joint powder you add to your dog's normal food, and gives higher daily amounts of glucosamine and MSM (2,500mg each for a medium dog, compared with 1,000mg in Max Strength Plus).

How do I feed it?

Mix with warm water to make a porridge, stir it into wet food, or sprinkle it over wet or dry food. A medium dog (15–40kg) needs one level scoop (about 40g) a day.

How long does a tub last?

A 1.2kg tub lasts a medium dog (15–40kg) around 30 days, a small dog (up to 15kg) around 60 days and a large dog (40kg+) around 20 days.

From what age can my dog have it?

We recommend feeding it from 9 to 12 months old upwards.

Is it suitable for raw-fed or sensitive dogs?

Yes. It complements all diets, including raw, and it's gluten and wheat free.

Is it suitable for competition and working dogs?

Yes. None of the ingredients are banned by the GBGB, IGB, ISDS, British Flyball Association, IFSS, the Kennel Club, UK Agility or BASC.

Can I give it alongside medication?

If your dog takes medication, is injured or has an ongoing health condition, please check with your vet before using this supplement.

Can I claim for it on pet insurance?

Some of our customers have successfully claimed for this supplement through Petplan. Check your own policy, as cover varies.

Find out more about claiming on pet insurance

Note for competition and working dogs

(Greyhounds, sheepdogs, flyball, sled dogs, agility, gundogs and more)

All the ingredients in our products are natural and contain no prohibited or banned substances. None of our ingredients are banned by:

• Great Britain Greyhound Board (GBGB)
• Irish Greyhound Board (IGB)
• The International Sheep Dog Society (ISDS)
• British Flyball Association (BFA)
• International Federation of Sleddog Sports (IFSS)
• The Kennel Club
• UK Agility (UKA)
• The British Association for Shooting and Conservation (BASC)

All Winston & Porter products are developed in line with European Pet Food Industry Federation (FEDIAF) and National Research Council (NRC) nutritional guidelines.

Good to know

♻️ Packaging: all our containers, scoops and packaging are recyclable, and we reuse boxes wherever possible to reduce our carbon footprint. The 5kg and 10kg sizes come in strong, recyclable brown paper sacks. Refurbished, fully sanitised resealable tubs are also available as an eco-friendly option.

We're unable to offer next-day delivery to the Scottish Highlands and Islands, the Isle of Man, the Channel Islands or international addresses.

Read more: Supporting joint health and mobility from puppy to senior · Best dog joint supplements UK (2026 guide)

Important information

• Contraindications: do not use if your dog has a known allergy, hypersensitivity or intolerance to any of the listed ingredients.
• Adverse reactions: in the unlikely event that your dog becomes unwell after use, stop immediately and seek veterinary advice.
• Disclaimer: this is a nutritional supplement and is not intended to diagnose, treat, cure or prevent disease. No guarantee of prevention or recovery is implied. If your dog is injured, has persistent stiffness or reduced mobility, or takes medication, speak to your vet before use.