Herbs & botanicals
Milk thistle
Seeds of the milk thistle plant. Taken for the liver – studies are mixed.
102 products from US online stores, sorted by what 300 mg of milk thistle extract costs – not by the price per pack.
0.87¢Lowest cost
per 300 mg milk thistle extract
- Prices checked Nov 1, 2026, US
- No paid placements
What does 300 mg mean?
- milk thistle extract per serving in most of the products we checked
- 160–2,000 mgmilk thistle extract per serving in most of the products we checked
- 300 mg is about one serving: half of the 102 products we checked have up to 250 mg per serving, the other half more.
- There’s no official daily amount for milk thistle extract.
We compare by 300 mg only so products line up – it’s not a recommendation. Not medical advice.
Where products miss quality points
How the 102 products score
- Very good 90+: 4
- Good 75+: 96
- Fair 60+: 2
- Low under 60: 0
- have no seal from an independent testing program
- 96%have no seal from an independent testing program10 of 30 testing points for GMP, 15 for the 9 whose label says “third-party tested”
The full 30 testing points need an independent test. Every supplement sold in the US is made under the FDA’s GMP rules – the maker checks its own products, which gives 10 points. A seal from a testing program like NSF, USP or Informed Choice means a lab outside the company checks that what’s inside matches the label. Most brands don’t take part. That doesn’t make a product bad – without a seal, a clean product still gets up to 80.
We find seals on the label and in NSF’s public lists. USP and Informed Choice don’t let us search their lists automatically, so a seal that’s only in their lists can be missing. How the score works
Pack size
Compare packs of a similar size.
All sizes in one list can affect the results – big packs usually cost less per 300 mg. Pick a size above to compare packs that are alike.
102 products · cheapest per 300 mg milk thistle extract first
- Rank 1
Frontier Co-op
Milk Thistle Seed, Whole
Loose herb · Powder
75Good qualityCountry not stated0.87¢per 300 mg
Lowest
- Pack
- $13.10453 g (1 lb)151 servings
- Milk thistle extract per serving
- 3,000 mgin 3 g
- Pack lasts
- 1,510 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 2
Frontier Co-op
Organic Whole Milk Thistle Seed
Loose herb · Powder
75Good qualityCountry not stated1¢per 300 mg
19% more
- Pack
- $15.65453 g (1 lb)151 servings
- Milk thistle extract per serving
- 3,000 mgin 3 g
- Pack lasts
- 1,510 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 3
Nature's Truth
Milk Thistle 2000 mg
Whole herb · Capsules
75Good qualityCountry not stated2.5¢per 300 mg
194% more
- Pack
- $16.98200 capsules100 servings
- Milk thistle extract per serving
- 2,000 mgin 2 capsules
- Pack lasts
- 200 daysif you take 1 capsule (1,000 mg) a day
naturestruth.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 4
Nutricost
Organic Milk Thistle Powder
Extract · Powder
80Good qualityCountry not stated3.6¢per 300 mg
311% more
- Pack
- $26.97227 g (8 oz)568 servings
- Milk thistle extract per serving
- 400 mgin 0.4 g
- Pack lasts
- 756 daysif you take 300 mg a day
nutricost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 5
BareOrganics
Organic Milk Thistle Seed Powder
Whole herb · Powder
75Good qualityMade in USA3.6¢per 300 mg
311% more
- Pack
- $26.99227 g (8 oz)76 servings
- Milk thistle extract per serving
- 3,000 mgin 3 g
- Pack lasts
- 756 daysif you take 300 mg a day
bareorganics.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 6
Nature's Truth
Milk Thistle Seed, 1,000 mg
Extract · Capsules
75Good qualityCountry not stated3.8¢per 300 mg
341% more
- Pack
- $12.75100 capsules
- Milk thistle extract per serving
- 1,000 mgin 1 capsule
- Pack lasts
- 100 daysif you take 1 capsule (1,000 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 7
Nutricost
Organic Milk Thistle, Unflavored
Extract · Powder
85Good qualityPacked in USA4¢per 300 mg
366% more
- Pack
- $30.61227 g (8 oz)568 servings
- Milk thistle extract per serving
- 400 mgin 0.4 g
- Pack lasts
- 756 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 8
Swanson Vitamins
Full Spectrum Milk Thistle, 500 mg
Whole herb · Capsules
75Good qualityCountry not stated6.7¢per 300 mg
667% more
- Pack
- $11.09100 capsules50 servings
- Milk thistle extract per serving
- 1,000 mgin 2 capsules
- Pack lasts
- 100 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 9
Swanson Vitamins
Full Spectrum Milk Thistle
Whole herb · Capsules
75Good qualityCountry not stated6.7¢per 300 mg
667% more
- Pack
- $11.09100 capsules50 servings
- Milk thistle extract per serving
- 1,000 mgin 2 capsules
- Pack lasts
- 100 daysif you take 1 capsule (500 mg) a day
swansonvitamins.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 10
Mason Natural
Milk Thistle, Whole Herb, 500 mg
Whole herb · Capsules
75Good qualityMade in USA6.9¢per 300 mg
699% more
- Pack
- $6.9360 capsules
- Milk thistle extract per serving
- 500 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 11
Nutricost
Milk Thistle
Extract · Capsules
80Good qualityMade in USA7¢per 300 mg
704% more
- Pack
- $13.95240 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 120 daysif you take 2 capsules (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 12
Micro Ingredients
Organic Milk Thistle Powder
Whole herb · Powder
85Good qualityCountry not stated7.2¢per 300 mg
728% more
- Pack
- $23.95100 g (3.5 oz)400 servings
- Milk thistle extract per serving
- 250 mgin 0.25 g
- Pack lasts
- 333 daysif you take 300 mg a day
microingredients.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 13
Toniiq
Milk Thistle 1000
Whole herb · Capsules
80Good qualityCountry not stated7.5¢per 300 mg
764% more
- Pack
- $29.97240 capsules120 servings
- Milk thistle extract per serving
- 1,000 mgin 2 capsules
- Pack lasts
- 240 daysif you take 1 capsule (500 mg) a day
toniiq.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 14
Vitacost
Synergy, Milk Thistle Liquid Extract, Alcohol Free
Extract · Liquid
75Good qualityCountry not stated7.7¢per 300 mg
784% more
- Pack
- $7.5729.6 ml (1 fl oz)15 servings
- Milk thistle extract per serving
- 2,000 mgin 2 ml
- Pack lasts
- 98 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 15
Nutricost
Milk Thistle Capsules
Extract · Capsules
80Good qualityMade in USA8¢per 300 mg
820% more
- Pack
- $15.97240 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 120 daysif you take 2 capsules (500 mg) a day
nutricost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 16
Eclectic Herb
Milk Thistle
Whole herb · Capsules
80Good qualityCountry not stated8¢per 300 mg
828% more
- Pack
- $19.32120 capsules30 servings
- Milk thistle extract per serving
- 2,400 mgin 4 capsules
- Pack lasts
- 120 daysif you take 1 capsule (600 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 17
Toniiq
Milk Thistle 1000
Extract · Capsules
80Good qualityCountry not stated8.2¢per 300 mg
850% more
- Pack
- $32.97240 capsules120 servings
- Milk thistle extract per serving
- 1,000 mgin 2 capsules
- Pack lasts
- 240 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 18
NOW Foods
Milk Thistle Extract, 750 mg
Extract · Capsules
75Good qualityMade in USA9.8¢per 300 mg
1,027% more
- Pack
- $21.9990 capsules
- Milk thistle extract per serving
- 750 mgin 1 capsule
- Pack lasts
- 90 daysif you take 1 capsule (750 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 19
Eclectic Herb
Milk Thistle Capsules
Whole herb · Capsules
80Good qualityCountry not stated9.8¢per 300 mg
1,027% more
- Pack
- $23.46120 capsules30 servings
- Milk thistle extract per serving
- 2,400 mgin 4 capsules
- Pack lasts
- 120 daysif you take 1 capsule (600 mg) a day
eclecticherb.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 20
Nature's Answer
Organic Milk Thistle - Veggie Capsules
Whole herb · Capsules
75Good qualityMade in USA$0.10per 300 mg
1,051% more
- Pack
- $6.9960 capsules
- Milk thistle extract per serving
- 350 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (350 mg) a day
naturesanswer.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 21
Nutricost
Milk Thistle, 1,000 mg
Extract · Capsules
80Good qualityMade in USA$0.10per 300 mg
1,052% more
- Pack
- $9.99120 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 60 daysif you take 2 capsules (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 22
Nature's Answer
Milk Thistle Seed, Fluid Extract, Alcohol-Free
Extract · Liquid
75Good qualityCountry not stated$0.10per 300 mg
1,084% more
- Pack
- $40.49118.3 ml (4 fl oz)59 servings
- Milk thistle extract per serving
- 2,000 mgin 2 ml
- Pack lasts
- 394 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 23
Primaforce
Milk Thistle
Extract · Capsules
80Good qualityCountry not stated$0.10per 300 mg
1,110% more
- Pack
- $15.74180 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 90 daysif you take 2 capsules (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 24
Nature's Answer
Milk Thistle Seed, Fluid Extract, Alcohol-Free
Extract · Liquid
75Good qualityMade in USA$0.11per 300 mg
1,216% more
- Pack
- $22.4959.1 ml (2 fl oz)30 servings
- Milk thistle extract per serving
- 2,000 mgin 2 ml
- Pack lasts
- 197 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 25
Primaforce
Milk Thistle Capsules
Extract · Capsules
75Good qualityCountry not stated$0.12per 300 mg
1,282% more
- Pack
- $17.99180 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 90 daysif you take 2 capsules (500 mg) a day
primaforce.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 26
Swanson Vitamins
Full Spectrum Milk Thistle
Whole herb · Capsules
75Good qualityCountry not stated$0.13per 300 mg
1,350% more
- Pack
- $6.2930 capsules15 servings
- Milk thistle extract per serving
- 1,000 mgin 2 capsules
- Pack lasts
- 30 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 27
Swanson Vitamins
Full Spectrum Milk Thistle
Whole herb · Capsules
75Good qualityCountry not stated$0.13per 300 mg
1,350% more
- Pack
- $6.2930 capsules15 servings
- Milk thistle extract per serving
- 1,000 mgin 2 capsules
- Pack lasts
- 30 daysif you take 1 capsule (500 mg) a day
swansonvitamins.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 28
Nutricost
Milk Thistle, 300 mg
Extract · Capsules
85Good qualityMade in USA$0.13per 300 mg
1,379% more
- Pack
- $15.40120 capsules
- Milk thistle extract per serving
- 300 mgin 1 capsule
- Pack lasts
- 120 daysif you take 1 capsule (300 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 29
Nature's Answer
Milk Thistle Seed, Fluid Extract, Alcohol-Free
Extract · Liquid
75Good qualityMade in USA$0.13per 300 mg
1,388% more
- Pack
- $12.7429.6 ml (1 fl oz)15 servings
- Milk thistle extract per serving
- 2,000 mgin 2 ml
- Pack lasts
- 98 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 30
Toniiq
Milk Thistle 50:1
Extract · Capsules
80Good qualityCountry not stated$0.13per 300 mg
1,435% more
- Pack
- $19.9790 capsules
- Milk thistle extract per serving
- 500 mgin 1 capsule
- Pack lasts
- 90 daysif you take 1 capsule (500 mg) a day
toniiq.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 31
NOW Foods
Milk Thistle Extract, 450 mg
Extract · Softgels
75Good qualityMade in USA$0.14per 300 mg
1,528% more
- Pack
- $25.42120 softgels
- Milk thistle extract per serving
- 450 mgin 1 softgel
- Pack lasts
- 120 daysif you take 1 softgel (450 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 32
Vitacost
Synergy, Milk Thistle Extract
Extract · Capsules
75Good qualityCountry not stated$0.14per 300 mg
1,547% more
- Pack
- $14.29100 capsules50 servings
- Milk thistle extract per serving
- 600 mgin 2 capsules
- Pack lasts
- 100 daysif you take 1 capsule (300 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 33
Swanson Vitamins
Milk Thistle
Extract · Capsules
80Good qualityCountry not stated$0.15per 300 mg
1,616% more
- Pack
- $14.89120 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 60 daysif you take 2 capsules (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 34
Swanson Vitamins
Milk Thistle - Features 80% Silymarin
Extract · Capsules
80Good qualityCountry not stated$0.15per 300 mg
1,616% more
- Pack
- $14.89120 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 60 daysif you take 2 capsules (500 mg) a day
swansonvitamins.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 35
Nature's Answer
Milk Thistle Extract - Alcohol Free Liquid
Extract · Liquid
75Good qualityMade in USA$0.15per 300 mg
1,628% more
- Pack
- $29.9930 servings
- Milk thistle extract per serving
- 2,000 mg
- Pack lasts
- 200 daysif you take 300 mg a day
naturesanswer.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 36
Sundance Vitamins
Milk Thistle
Extract · Capsules
75Good qualityCountry not stated$0.16per 300 mg
1,696% more
- Pack
- $7.7960 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 30 daysif you take 2 capsules (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 37
Swanson Vitamins
Milk Thistle Liquid Extract, Alcohol & Sugar Free
Extract · Liquid
75Good qualityCountry not stated$0.17per 300 mg
1,803% more
- Pack
- $16.2929.6 ml (1 fl oz)15 servings
- Milk thistle extract per serving
- 2,000 mgin 2 ml
- Pack lasts
- 98 daysif you take 300 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 38
Swanson Vitamins
Milk Thistle Liquid Extract - Alcohol & Sugar Free
Extract · Liquid
75Good qualityCountry not stated$0.17per 300 mg
1,803% more
- Pack
- $16.2929.6 ml (1 fl oz)15 servings
- Milk thistle extract per serving
- 2,000 mgin 2 ml
- Pack lasts
- 98 daysif you take 300 mg a day
swansonvitamins.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 39
Nature's Bounty
Milk Thistle, 250 mg
Extract · Capsules
80Good qualityMade in USA$0.17per 300 mg
1,838% more
- Pack
- $28.02200 capsules
- Milk thistle extract per serving
- 250 mgin 1 capsule
- Pack lasts
- 100 daysif you take 2 capsules (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 40
Amazing Nutrition
Amazing Formulas Milk Thistle - 175 Mg
Extract · Capsules
80Good qualityMade in USA$0.17per 300 mg
1,873% more
- Pack
- $11.98120 capsules
- Milk thistle extract per serving
- 175 mgin 1 capsule
- Pack lasts
- 60 daysif you take 2 capsules (350 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
Good to know
- Fact
- 21,480%more per 300 mg for the most expensive product than for the cheapest.
- Fact
- 311%more per 300 mg for the cheapest extract than for the cheapest loose herb.
How we checked: one-time price for each size in the store’s US online shop, before sales tax and shipping, without subscriptions or coupons. Prices change often, so check the store before you buy. More on how we check
The amount we compare by only makes products comparable – it is not a dosage recommendation. Not medical advice.
How we calculate
Cost per dose = price ÷ (servings × amount per serving) × comparison amount. Example: $119.99 for 74 servings with 24 g of protein each is 1,776 g of protein. $119.99 ÷ 1,776 g × 30 g = $2.03 per 30 g of protein.
Found a mistake or a product we should add? Email us