Best Milk Thistle Supplements 2026: Cost per Effective Dose
Top pick for Milk Thistle: NOW Foods Silymarin Milk Thistle Extract 300 mg, Double Strength (100 Capsules) — 300mg milk thistle extract per 1 capsule (300 mg), None (GMP), $0.17/day. Our best-value pick.
Registry check · Milk Thistle
Does anyone independently verify Milk Thistle supplements?
2 of these 12 products are confirmed in NSF/ANSI 173, which puts this category in the minority with any verified option at all. The other 10 are not listed anywhere we can check — not evidence against them, only an absence of independent confirmation.
Certification is not a dosing guarantee. Across the whole catalogue, certified products reach the clinically studied dose 57% of the time and uncertified ones 71% — a gap too small to mean anything (Fisher p = 0.185). Read the Milk Thistle dose column either way.
12 checked against all 5,317 US NSF, USP and Informed Sport listings, 2026-08-25. Full method and limitations.
What 12 Milk Thistle labels show
Priced per day, these milk thistle products run $0.10 to $1.28 — a 13× gap between the cheapest and dearest milk thistle here, across 11 brands.
All Milk Thistle Supplements Compared
| Product | Brand | Dose / Serving | Cost / Day | Certification (as labelled) | Pick | Buy |
|---|---|---|---|---|---|---|
| Swanson Full Spectrum Milk Thistle 500 mg (100 Capsules) | Swanson | 500mg milk thistle seed / 1 capsule (500 mg) | $0.10 | None | Buy | |
| Horbaach Milk Thistle 3000 mg, 4:1 Extract (300 Capsules) | Horbaach | 3000mg milk thistle (4:1 equiv) / 2 capsules (3000 mg equiv) | $0.11 | None | Buy | |
| NOW Foods Silymarin Milk Thistle Extract 300 mg, Double Strength (100 Capsules) | NOW Foods | 300mg milk thistle extract / 1 capsule (300 mg) | $0.17 | None (GMP) | Best Value | Buy |
| Jarrow Formulas Milk Thistle 150 mg, 30:1 Standardized (100 Capsules) | Jarrow Formulas | 150mg milk thistle extract / 1 capsule (150 mg) | $0.17 | None (Non-GMO) | Buy | |
| Nature's Bounty Milk Thistle 1000 mg, Rapid Release Softgels (50 ct) | Nature's Bounty | 1000mg milk thistle / 1 softgel (1000 mg) | $0.19 | None | Buy | |
| Nature's Way Milk Thistle, 175 mg Seed Extract, 80% Silymarin (120 Capsules) | Nature's Way | 175mg milk thistle extract / 1 capsule (175 mg) | $0.29 | None (TRU-ID authenticated) | Buy | |
| Pure Encapsulations Silymarin 250 mg (120 Capsules) | Pure Encapsulations | 250mg milk thistle extract / 1 capsule (250 mg) | $0.38 | None (hypoallergenic) | Buy | |
| Himalaya Milk Thistle Liver Support 350 mg (60 Capsules) | Himalaya | 350mg herb blend / 1 capsule (350 mg) | $0.43 | USDA Organic + Non-GMO Verified | Buy | |
| Solaray Milk Thistle One Daily, Seed Extract 350 mg (60 Capsules) | Solaray | 350mg milk thistle extract / 1 capsule (350 mg) | $0.50 | None (lab verified) | Buy | |
| Thorne Milk Thistle Phytosome (Siliphos) (90 Capsules) | Thorne | mg silybin phytosome / 1 capsule | $0.54 | Third-party certified (Thorne) | Buy | |
| Thorne S.A.T. — Milk Thistle + Artichoke + Turmeric (60 Capsules) | Thorne | mg herb blend / 1 capsule | $0.78 | Third-party certified (Thorne) | Buy | |
| Gaia Herbs Milk Thistle Seed, Liquid Phyto-Caps (120 Capsules) | Gaia Herbs | mg milk thistle seed / 3 capsules | $1.28 | None | Buy |
Our Picks
Best Value: NOW Foods Silymarin Milk Thistle Extract 300 mg, Double Strength (100 Capsules)
300mg milk thistle extract per 1 capsule (300 mg). None (GMP). $0.17/day. 100 servings per container at $17.20.
NOW Foods Silymarin Milk Thistle Extract 300 mg, Double Strength (100 Capsules) →
The shelf · Milk Thistle
These Milk Thistle servings are not comparable to each other
Jarrow Formulas Milk Thistle 150 mg, 30:1 Standardized (100 Capsules) states 150 mg a serving and Horbaach Milk Thistle 3000 mg, 4:1 Extract (300 Capsules) states 3,000 mg — both occupy one row of the same price column. So Swanson Full Spectrum Milk Thistle 500 mg (100 Capsules) showing 10¢ a day, the lowest here, may be reporting a smaller serving rather than a better price. Before comparing Swanson Full Spectrum Milk Thistle 500 mg (100 Capsules) with Gaia Herbs Milk Thistle Seed, Liquid Phyto-Caps (120 Capsules), check what each calls a serving.
Method: the 12 Milk Thistle products above, compared on label facts — serving size, servings per container, form, price. Not a dosing recommendation.
The evidence · Milk Thistle
What the published reviews of Milk Thistle concluded
- Milk thistle for the treatment of liver disease: a systematic review and meta-analysis. · The American journal of medicine, 2002
“Treatment with milk thistle appears to be safe and well tolerated. We found no reduction in mortality, in improvements in histology at liver biopsy, or in biochemical markers of liver function among patients with chronic liver disease.”
- Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases. · The Cochrane database of systematic reviews, 2007
“Our results question the beneficial effects of milk thistle for patients with alcoholic and/or hepatitis B or C virus liver diseases and highlight the lack of high-quality evidence to support this intervention.”
- Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases. · The Cochrane database of systematic reviews, 2005
“Our results question the beneficial effects of milk thistle for patients with alcoholic and/or hepatitis B or C virus liver diseases and highlight the lack of high-quality evidence to support this intervention.”
- Prophylactic Therapy of Silymarin (Milk Thistle) on Antituberculosis Drug-Induced Liver Injury: A Meta-Analysis of Randomized Controlled Trials. · Canadian journal of gastroenterology & hepatology, 2019
“Prophylactic therapy of silymarin is contributed to a noticeably reduced risk of development of anti-TB DILI four weeks after the initiation. In addition, silymarin significantly improved the liver function in patients who are receiving anti-TB drugs.”
Method: PubMed searched in humans for systematic reviews and meta-analyses with Milk Thistle in the title; these 4 of the 6 that qualified are shown with the authors’ own conclusion quoted rather than summarised. What it cannot tell you: whether Milk Thistle will work for you — each of these reports an average across trials published 2002–2019, and null findings are shown here as readily as positive ones.
How these 12 Milk Thistle products were ranked
2 of these 12 are confirmed in a certifier's registry — the only milk thistle rows where the claim is independently backed — and the rest are ranked on cost per day at the labelled serving. Commission does not enter it: the rate is the same whichever milk thistle you buy. Full methodology.