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Milk thistle
The fruit of a thistle, taken as an extract of silymarin, a group of plant compounds. It has an EMA herbal monograph for supporting the liver and no authorised EU health claim, and we use it in one formula that is still in development. If you are allergic to plants of the daisy family, it is not for you, with no exceptions.
WHAT WE ARE ALLOWED TO SAY
Nothing yet. The claims are on hold.
Milk thistle has no authorised health claim under Regulation (EU) 432/2012. Several of its claims sit on the European Commission's on-hold list, where most botanical claims have waited since 2010 for an EFSA assessment. Until that ends, we make no health claim for it, and you will not find one on this page.Milk thistle has no authorised health claim under Regulation (EU) 432/2012. Its claims are on hold, waiting for an EFSA assessment. Until then, we make no health claim for it.
Milk thistle has no authorised claim for the liver or for digestion. We use it in a liver formula, but the authorised claim in that formula belongs to the choline next to it, not to the milk thistle. Its EMA monograph covers traditional use for digestive complaints, such as fullness and slow digestion, and for supporting liver function, which is a medicines assessment, not a food claim. Our file also cites a Cochrane review of milk thistle in liver disease. That is a reason to keep it in the library, not a permission to promise anything.
WHY AN EXTRACT
The fruit, standardised to its silymarin.
Milk thistle is a plant, so the choice is not between salts but between preparations. Our file takes the fruit and extracts silymarin from it, a mix of plant compounds led by silybin. It prefers an extract standardised to 70–80% silymarin, ideally with the silybin bound to a phospholipid, phosphatidylcholine, so that more of it is taken up.
The dried fruit, ground. It is the other preparation in the EMA monograph on file, at 3 to 5 g two or three times a day.
An extract of the fruit standardised to its silymarin content. The monograph doses on file are for extracts with 70 to 80% silymarin, and our formula records 70%.
Silybin bound to phosphatidylcholine. Our file records that only 20 to 50% of silybin is absorbed on its own and that the phospholipid form improves it. It dissolves in oil, tastes bitter and is sensitive to light.
There is no authorised claim for any form of milk thistle, standardised or not, so the standard is not a claim argument and we do not use it as one. Our files do not yet agree on it: the formula records an extract at 70% silymarin, our regulatory file names at least 80% in the phospholipid form, and neither says whether the 400 mg is extract or silymarin. That gap is still open, and our milk thistle file is a draft, pending review by a clinical professional.There is no authorised claim for any form of milk thistle, standardised or not. Our files do not yet agree on the standard, 70% or at least 80% silymarin, and our file is still pending clinical review.
WHERE IT APPEARS
One of the twenty-nine carries milk thistle.
Only Liver (ALT / AST), an ADAPT formula still in development, next to choline, artichoke and vitamin E. It goes out at night, with dinner. Our milk thistle file would take it with food, which helps a compound that dissolves in fat, split across two or three doses a day. This formula serves it once, and we would rather say that than hide it.
THE CEILING
No official limit. Our cap: 600 mg of silymarin a day.
EFSA has not set a tolerable upper intake level for milk thistle, and the EMA monograph gives doses, not a limit. Our files do not yet agree on those doses: one records 200 to 400 mg of standardised extract a day, another 140 to 420 mg of silymarin, and a third 140 to 600 mg. The cap in our file is our own: 600 mg of silymarin a day, added up across every formula. No limit is not the same as no risk.EFSA has not set an upper intake level for milk thistle, so the cap is ours: 600 mg of silymarin a day across everything you take. No limit is not the same as no risk.
600 mg of silymarin a day across everything you take. Our file flags doubling up with other ingredients that act on the liver and bile: artichoke, dandelion and boldo. Today only Liver (ALT / AST) carries milk thistle, at 400 mg, and artichoke shares that dose.
Not if you are allergic to plants of the daisy family (Asteraceae), such as daisies, chamomile or ragweed: that is an absolute contraindication in our file and in the EMA monograph. Planned surgery: stop it a week before, because it slows liver enzymes that clear many medicines. Pregnancy and breastfeeding: not enough data, and the EMA does not recommend it. Under 18: not enough data. Oestrogen-sensitive conditions such as breast or endometrial cancer: caution, as silybin may in theory have a weak oestrogen-like effect. On anticoagulants: to be monitored. Cancer treatment: no specific contraindication on file, but its interaction with chemotherapy has to be checked. Liver disease: not with severe cholestasis unless a doctor supervises it. Kidney disease, heart disease or arrhythmias: no restriction on file. In Liver (ALT / AST), taking a vitamin K antagonist such as warfarin or acenocoumarol, or having known liver disease, rules the formula out.
Our file rates it as very well tolerated. Mild stomach upset, including a mild laxative effect, headache and itching, and, rarely, a severe allergic reaction in people allergic to the daisy family. It contains none of the allergens the EU requires on a label, and no intolerance or dietary restriction is documented. The label warning on file: stop taking it if you notice signs of a liver problem, such as yellowing of the skin or eyes, unusual tiredness, abdominal pain or dark urine, and ask first if you have known liver disease. The EMA monograph adds: if your symptoms last longer than 2 weeks, see a doctor.
WHAT IT REACTS WITH
Seven documented pairs. Two medicines.
Milk thistle is one of the 140 ingredients in our library, so it has 139 possible partners. Seven of its pairs are documented in our interaction table so far, out of the 443 on file, and two medicines are in our drug interaction table. Our ingredient file flags others below, which have not been entered in those tables yet.
Charcoal binds the polyphenols in milk thistle, rated high: never in the same dose, and at least 3 hours apart. White clay holds back plant compounds too, rated medium: at least 2 hours apart. Iron is filed as a synergy rated medium: silymarin binds iron in laboratory studies, which is why it has been studied as an add-on in iron overload, and why the two stay at least 2 hours apart when your plan is for low iron stores. It does not replace medical treatment for iron overload.
All four are documented as low-severity synergies. Artichoke adds its effect on bile flow, and our table marks the two as a valid pairing: they share the dose in Liver (ALT / AST). Turmeric and schisandra are filed as pairings that act on the liver in similar ways, and coenzyme Q10 as combinable. Complementary means they can share a dose; it is not a promise about your liver.
Our file lists NAC, liposomal glutathione and vitamin E as partners that act on the liver's antioxidant defences, and dandelion and boldo as acting on the liver and bile, with a note to limit doubling up. It also pairs milk thistle with ashwagandha and kava, two herbs with liver warnings of their own, on the idea that it may offset them. None of these is in our interaction table yet, and that idea is not a promise.
Two are in our drug interaction table, both rated high. Tamoxifen: milk thistle slows CYP3A4, an enzyme tamoxifen needs to become active, so it could work less well; avoid the combination during treatment and ask your oncologist before starting. Warfarin: it slows CYP2C9, which clears warfarin, and can raise your INR and the risk of bleeding; the record asks for weekly INR checks when starting or changing it, and to avoid it or keep silymarin under 200 mg a day. Our file also flags medicines cleared by the same enzymes, such as statins, ciclosporin, tacrolimus, indinavir, phenytoin, sildenafil and glibenclamide, as well as raloxifene and chemotherapy, and diabetes medication, where the effects on blood sugar may add up. In Liver (ALT / AST), a vitamin K antagonist rules the formula out, and the app asks about medication before it is assigned.
443 of the 9,730 possible pairs in our library are documented, which is 4.55%, and seven of them involve milk thistle. The rest are not "safe", they are simply unchecked, and we would rather write that down than let the number look like a badge.443 of the 9,730 possible pairs in our library are documented, which is 4.55%, and seven involve milk thistle. The rest are not safe, they are simply unchecked.
SOURCES
Everything on this page, with its reference.
Reviewed by VION nutrition team · last reviewed 16 September 2026
140 INGREDIENTS · 64 IN USE TODAY
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