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 pick.
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) | $0.09 | None | Buy | |
| Horbaach Milk Thistle 3000 mg, 4:1 Extract (300 Capsules) | Horbaach | 3,000mg 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) | Our Pick | 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 | 1,000mg milk thistle / 1 softgel (1000 mg) | $0.17 | None | Buy | |
| Nature's Way Milk Thistle, 175 mg Seed Extract, 80% Silymarin (60 Capsules) | Nature's Way | 175mg milk thistle extract / 1 capsule (175 mg) | $0.22 | 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) | $0.47 | None (lab verified) | Buy | |
| Thorne Milk Thistle Phytosome (Siliphos) (90 Capsules) | Thorne | 1 capsule (amount not stated) | $0.53 | Third-party certified (Thorne) | Buy | |
| Thorne S.A.T. — Milk Thistle + Artichoke + Turmeric (60 Capsules) | Thorne | 1 capsule (amount not stated) | $0.78 | Third-party certified (Thorne) | Buy | |
| Gaia Herbs Milk Thistle Seed, Liquid Phyto-Caps (120 Capsules) | Gaia Herbs | 3 capsules (amount not stated) | $1.28 | None | Buy |
Registry check · Milk Thistle
Does anyone independently verify Milk Thistle supplements?
1 of the 12 Milk Thistle products on this page is confirmed in NSF/ANSI 173: Thorne S.A.T. — Milk Thistle + Artichoke + Turmeric (60 Capsules). Thorne S.A.T. — Milk Thistle + Artichoke + Turmeric (60 Capsules) does not show the mark on the listing, so the table’s certification column, which repeats the listing, does not show it either. For the others, the listing may name a certification, but we did not find it in a public registry — that is 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.
The 12 products on this page checked against all 5,317 US NSF, USP and Informed Sport listings, 2026-08-25. Full method and limitations.
What Milk Thistle labels show
Priced per day, these milk thistle products run $0.09 to $1.28 — a 14× gap between the cheapest and dearest milk thistle here, across 11 brands.
Our Picks
Our Pick: 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. 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.
How these 12 Milk Thistle products were ranked
1 of these 12 is confirmed in a certifier's registry — the only milk thistle row 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.