Look up a supplementAll guides

Best liver supplement for dogs

For most dogs, Denamarin, the SAMe and silybin tablet vets commonly use for the liver: a 50 lb dog gets 425 mg of SAMe and 35 mg of silybin (in a 120 mg silybin complex) a day for $2.50. A 25 lb dog gets 225 mg and 24 mg from the chewable for $1.50; for milk thistle, Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC) gives 112 mg for $0.34.

By Winslow Pet Health editors · Published · Numbers from each brand's own labels

Denamarin Tablets for Large Dogs (35 lb and over)

Best for dogs 35 lb and over

Denamarin Tablets for Large Dogs (35 lb and over)

425 mg SAMe a day35 mg silybin1 tablet for a 50 lb dog$2.50 a day1

$74.99 on Amazon
Denamarin Chewable Tablets, All Sizes

Best for dogs under 35 lb

Denamarin Chewable Tablets, All Sizes

225 mg SAMe a day24 mg silybin1 tablet for a 25 lb dog$1.50 a day2

$44.99 on Amazon
Denosyl Liver & Brain Support, Medium Dogs (13 to 34 lb)

Best SAMe only, for 13 to 34 lb

Denosyl Liver & Brain Support, Medium Dogs (13 to 34 lb)

225 mg SAMe a day1 tablet for a 25 lb dog$1.10 a day3

$32.99 on Amazon
Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC)

Best milk thistle, with the NASC seal

Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC)

112 mg milk thistle a day for a 25 lb dog (1 chew)224 mg for a 50 lb dog (2 chews)$0.34 a day at 25 lb$0.67 at 50 lb4

$30.35 on Amazon

We pick by what the label gives a day and what it costs a day for a 25 lb and a 50 lb dog. Prices on Amazon, October 28, 2026.5

A corgi gently taking a soft chew from a hand

Denamarin, per day

The version made for each weight, from its label

SAMeSilybin
10 lb dogChewable, ½ tablets · $0.75 a day113 mg12 mg
25 lb dogChewable, 1 tablet · $1.50 a day225 mg24 mg
50 lb dogLarge-dog tablet, 1 tablet · $2.50 a day425 mg35 mg
75 lb dogLarge-dog tablet, 2 tablets · $5.00 a day850 mg70 mg
100 lb dogLarge-dog tablet, 2 tablets · $5.00 a day850 mg70 mg

Silybin is the label's Silybin A+B. It sits inside a larger silybin-phosphatidylcholine complex (82 mg in the chewable, 120 mg in the large-dog tablet). Labels read October 2026.

Every liver supplement, per day by dog weight

SAMe products (Denamarin and Denosyl)

SAMe and silybin a day, how much to give, and the cost. A dash means the label has no dose for that weight.

Each weight column = what the label gives a dog that size each day, how much to give, and the cost a day at the Amazon price read October 28, 2026. Where a label gives a range, we use the low end. Silybin = the Silybin A+B on the label, which is part of the larger silybin complex.

Product10 lb25 lb50 lb75 lb100 lb
Denamarin Chewable Tablets, All Sizes225 mg SAMe + 24 mg silybin (in 82 mg silybin complex) a tablet · any size113 mg SAMe12 mg silybin½ tablets$0.75 a day225 mg SAMe24 mg silybin1 tablet$1.50 a day450 mg SAMe48 mg silybin2 tablets$3.00 a day563 mg SAMe60 mg silybin2½ tablets$3.75 a day788 mg SAMe84 mg silybin3½ tablets$5.25 a day
Denamarin Tablets for Large Dogs (35 lb and over)425 mg SAMe + 35 mg silybin (in 120 mg silybin complex) a tablet · dogs 35 lb and up——425 mg SAMe35 mg silybin1 tablet$2.50 a day850 mg SAMe70 mg silybin2 tablets$5.00 a day850 mg SAMe70 mg silybin2 tablets$5.00 a day
Denosyl Liver & Brain Support, Medium Dogs (13 to 34 lb)225 mg SAMe a tablet · dogs 13 to 34 lb—225 mg SAMe1 tablet$1.10 a day———

Milk thistle products

Milk thistle a day, how much to give, and the cost.

Each weight column = what the label gives a dog that size each day, how much to give, and the cost a day at the Amazon price read October 28, 2026. Where a label gives a range, we use the low end.

Product10 lb25 lb50 lb75 lb100 lb
Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC) (NASC seal)112 mg milk thistle a chew · any size · a blend with N-acetyl cysteine, curcumin and choline112 mg milk thistle1 chew$0.34 a day112 mg milk thistle1 chew$0.34 a day224 mg milk thistle2 chews$0.67 a day224 mg milk thistle2 chews$0.67 a day336 mg milk thistle3 chews$1.01 a day
VetriScience Liver Health Chews (NASC seal)50 mg milk thistle a chew · label: 1 chew a day per 30 lb · formerly Vetri Liver Canine; a blend with betaine, whey protein, artichoke and turmeric17 mg milk thistle0.3 chews$0.22 a day42 mg milk thistle0.8 chews$0.55 a day83 mg milk thistle1.7 chews$1.10 a day125 mg milk thistle2½ chews$1.65 a day167 mg milk thistle3.3 chews$2.20 a day
Wonder Paws Superhero Milk Thistle Liquid (NASC seal)50 mg milk thistle a ml · any size50 mg milk thistle1 ml$0.33 a day50 mg milk thistle1 ml$0.33 a day50 mg milk thistle1 ml$0.33 a day100 mg milk thistle2 ml$0.66 a day100 mg milk thistle2 ml$0.66 a day

Source: Each brand's label; Amazon prices read October 28, 20265

How to give it

Give SAMe on an empty stomach, at least an hour before a meal or two hours after one. If it makes your dog vomit that way, give later doses with a small bite of food.6 Liver disease needs a vet's diagnosis, and your vet's directions can differ from the label.6 Nutramax also sells a separate Denamarin tablet for cats and small dogs.7

The NASC Quality Seal

The National Animal Supplement Council gives its Quality Seal to companies that pass a third-party audit; a company can't buy it.8 Going by NASC's member list, Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC) and Wonder Paws Superhero Milk Thistle Liquid come from makers with the seal, and so does VetriScience Liver Health Chews, made by VetriScience (FoodScience).9

What the research says

VCA describes SAMe with silybin, the milk thistle extract in Denamarin, as a combination commonly used to support liver health in cats and dogs, and notes that limited studies have been done in animals.6 VCA calls SAMe on its own a commonly used supplement for liver disease in pets, especially cats and dogs.10

Questions people ask

What is the best liver supplement for dogs?
For most dogs, Denamarin: SAMe plus silybin. Denamarin Tablets for Large Dogs (35 lb and over) gives a 50 lb dog 425 mg of SAMe and 35 mg of silybin (in a 120 mg silybin complex) for $2.50 a day, and Denamarin Chewable Tablets, All Sizes gives a 25 lb dog 225 mg of SAMe and 24 mg of silybin (in 82 mg of complex) for $1.50 a day.
How much Denamarin should I give my dog?
The label for Denamarin Chewable Tablets, All Sizes gives tablets a day by weight: 0 to 6 lb: ¼; 7 to 15 lb: ½; 16 to 30 lb: 1; 31 to 45 lb: 1½; 46 to 60 lb: 2; 61 to 75 lb: 2½; 76 to 90 lb: 3; 91 to 105 lb: 3½; over 105 lb: 4. Denamarin Tablets for Large Dogs (35 lb and over): 35 to 65 lb: 1; 66 to 120 lb: 2; over 120 lb: 3 tablets. Your vet may change the number of tablets.6
Should Denamarin be given with food?
No. Give it on an empty stomach, at least an hour before a meal or two hours after one; if your dog vomits, give later doses with a small bite of food.6
What is the difference between Denamarin and Denosyl?
Denosyl has SAMe only: 225 mg a tablet, one tablet a day for a 13 to 34 lb dog, $1.10 a day. Denamarin adds silybin: the chewable has 225 mg of SAMe and 24 mg of silybin (in 82 mg of silybin complex) a tablet and costs $1.50 a day for a 25 lb dog.
What is the best liver supplement for small dogs?
For a 10 lb dog, Denamarin Chewable Tablets, All Sizes is the one SAMe and silybin product in our table with a dose at that weight: ½ tablets a day, 113 mg of SAMe and 12 mg of silybin, for $0.75 a day. For milk thistle, Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC) is 1 chew a day, $0.34.
What is VetriScience Liver Health Chews?
VetriScience Liver Health Chews (formerly Vetri Liver Canine) is a milk thistle blend with 50 mg of milk thistle, 500 mg of betaine and 50 mg of artichoke leaf extract in each chew. The label says 1 chew a day for every 30 lb, so a 50 lb dog gets 1.7 chews for $1.10 a day.
What is in a milk thistle liver chew?
Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC) has 112 mg of milk thistle in each chew, with 58 mg of N-acetyl cysteine, 58 mg of curcumin and 38 mg of choline. The label gives 0 to 25 lb: 1; 26 to 75 lb: 2; 76 lb and over: 3 chews by weight.

Notes and sources

  • Amounts per tablet or chew and the dose by weight come from each brand's label, read October 2026. See how we do the math.
  • How we pick: Denamarin Tablets for Large Dogs (35 lb and over) is the Denamarin made for dogs 35 lb and over; at 50 lb it costs $2.50 a day against $3.00 for the chewable, and it gives more SAMe per dollar at 50, 75 and 100 lb. Denamarin Chewable Tablets, All Sizes is the only SAMe and silybin product with a label dose below 35 lb. Denosyl Liver & Brain Support, Medium Dogs (13 to 34 lb) is the lowest cost for 225 mg of SAMe a day. Natural Dog Company Liver & Kidney Soft Chews (Milk Thistle + NAC) gives the most milk thistle a day per dollar of the sealed products at every weight.
  • Silybin is the "Silybin A+B" amount each Denamarin label prints (35 mg in the large-dog tablet, 24 mg in the chewable). The larger number on the label (120 mg and 82 mg) is the silybin-phosphatidylcholine complex that carries it.
  • Product photos come from Amazon.
  • Prices checked on Amazon October 28, 2026. Published .

Sources

  1. Nutramax label: Denamarin Liver Health Supplement for Large Dogs (35 lb and over), Coated Tablets, read October 2026.
  2. Nutramax label: Denamarin Liver Health, Chewable Tablets (all sizes), read October 2026.
  3. Nutramax label: Denosyl Liver & Brain Support for Medium Dogs (13-34 lb), read October 2026.
  4. Natural Dog Company label: Liver & Kidney (Milk Thistle + NAC) Soft Chews, Turkey (also sold as Detox Cleanse), read October 2026.
  5. Prices: Amazon product data, read October 28, 2026. Cost per serving = listing price divided by the servings in the container.
  6. VCA Animal Hospitals, "S-Adenosyl-Methionine (SAMe) + Silybin" (a combination supplement commonly used to support liver health in cats and dogs; give on an empty stomach, at least an hour before feeding or two hours after; follow your veterinarian's directions, which may differ from the label; limited studies in animals), read October 28, 2026.
  7. Nutramax, denamarin.com (Denamarin combines SAMe and silybin; chewable tablets for dogs of all sizes, coated tablets for medium dogs, coated tablets for cats and small dogs), read October 28, 2026.
  8. National Animal Supplement Council, home page ("Companies must earn the NASC Quality Seal; it cannot be purchased"), read October 28, 2026.
  9. National Animal Supplement Council, member list (a green check means permission to show the Quality Seal), read October 28, 2026.
  10. VCA Animal Hospitals, "S-Adenosyl-Methionine (SAMe)" (a commonly used supplement to treat liver disease in pets, especially cats and dogs), read October 28, 2026.

Labels for the products in the tables