supplementNot FDA-approvedOTC supplement
Milk ThistleBenefits, Dosage & Interactions
Also known as: Silymarin
Milk thistle (botanical name Silybum marianum) is a flowering herb related to the daisy and ragweed family. It is native to Mediterranean countries. Research on Milk Thistle focuses on healthy aging. It is typically taken with a meal. Dose, response, and interaction risk vary by individual, so use should be reviewed with a clinician.
How much Milk Thistle do people take?
The cited randomized trial used silymarin (milk thistle extract) 420 mg or 700 mg three times daily in adults with nonalcoholic steatohepatitis. Route reported: Oral. Frequency reported: Three times daily in the cited trial. These are amounts documented in the cited studies and labels for Milk Thistle — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Moderate — One published human randomized trial; results not yet replicated.
Evidence strengthModerate · 3/4
PreclinicalStrong human evidence
One published human randomized trial; results not yet replicated.
Plasma half-life
Not applicable
Typical timing
with a meal
Food rule
with food
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
- Reported amounts
- The cited randomized trial used silymarin (milk thistle extract) 420 mg or 700 mg three times daily in adults with nonalcoholic steatohepatitis[1]
- Route studied
- Oral[1]
- Frequency
- Three times daily in the cited trial[1]
- Cycle length
- 48 weeks in the cited trial[1]
- Half-life
- Roughly 6 hours[1]
- Storage
- Room temperature, sealed, protected from light[1]
Reported for Milk Thistle in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Milk Thistle entry is written from. Each number matches an inline marker above.
- [1]A Randomized Trial of Silymarin for the Treatment of Nonalcoholic SteatohepatitisNavarro VJ, Belle SH, D'Amato M, et al. · Clinical Gastroenterology and Hepatology · 2017 · Peer-reviewed · PMID 28419855
What is Milk Thistle studied for?
What is Milk Thistle?
Milk thistle (botanical name *Silybum marianum*) is a flowering herb related to the daisy and ragweed family. It is native to Mediterranean countries. Historically, milk thistle has been used for liver disorders and gallbladder problems. The active compounds in milk thistle are a group of flavonoids called silymarin. Silymarin is extracted from the seeds of the plant and is believed to be the primary reason for milk thistle's medicinal properties. It is commonly available as an oral supplement, often standardized to contain a certain percentage of silymarin. (NIH ODS)
What does the research say about Milk Thistle?
Tap a section to expand.
Silymarin, the active component of milk thistle, exerts its effects through several mechanisms, primarily related to its antioxidant and anti-inflammatory properties. It is thought to stabilize cell membranes, particularly liver cell membranes, and protect them from damage by toxins and free radicals. Silymarin can increase the intracellular content of glutathione, an important antioxidant in the body. It also appears to regulate immune function, inhibit lipid peroxidation, and promote protein synthesis, which can aid in liver cell regeneration. Furthermore, silymarin may modulate various signaling pathways involved in inflammation and fibrogenesis. (PubChem, DrugBank)
Milk thistle is most commonly known and used for its potential benefits to liver health. Research suggests it may help protect the liver from toxins and support its regenerative processes:
* **Liver Support:** Silymarin is believed to protect liver cells from damage caused by alcohol, medications, and other toxins. It may aid in detoxifying the liver and is often used by individuals with liver conditions such as alcoholic liver disease, non-alcoholic fatty liver disease (NAFLD), and liver inflammation. (NIH ODS, MedlinePlus)
* **Antioxidant Properties:** Silymarin is a potent antioxidant, helping to neutralize free radicals that can cause cellular damage throughout the body. This antioxidant activity contributes to its protective effects on the liver and may offer broader health benefits. (PubChem)
* **Anti-inflammatory Effects:** Studies suggest that silymarin possesses anti-inflammatory properties, which may contribute to its role in managing inflammatory conditions, including those affecting the liver. (DrugBank)
* **Potential Longevity Support:** Due to its antioxidant and anti-inflammatory properties, milk thistle is sometimes considered for broader health maintenance, potentially contributing to cellular health and longevity by mitigating oxidative stress. (Cochrane)
Clinical studies on milk thistle, particularly silymarin, have primarily focused on its efficacy in various liver conditions. A Cochrane review evaluating silymarin for alcoholic and non-alcoholic fatty liver disease noted that while some studies show beneficial effects on liver enzymes and histological improvements, the overall evidence quality for significant clinical outcomes such as mortality or liver-related morbidity is often limited or inconsistent. The review highlighted the need for more rigorously designed, larger clinical trials. Another meta-analysis, based on data from several randomized controlled trials, indicated that silymarin supplementation resulted in significant reductions in liver enzymes (ALT and AST) in patients with non-alcoholic fatty liver disease. (Cochrane, MedlinePlus)
For chronic hepatitis C, a systematic review found that while milk thistle is widely used, particularly as an alternative therapy, clinical trials evaluating its effect on viral load or liver biopsy results have shown conflicting and often inconclusive results. Some studies have indicated improvements in symptoms or liver function tests, but without clear evidence of antiviral activity or long-term benefits in this specific condition. (NIH ODS)
Further research is ongoing to fully understand the extent of milk thistle's benefits and its precise mechanisms across various health conditions.
Milk thistle is generally considered well-tolerated. The most commonly reported side effects are mild and include:
* Gastrointestinal upset (e.g., diarrhea, constipation, nausea, indigestion)
* Bloating
* Headache
* Itching (pruritus)
Allergic reactions, though rare, can occur, especially in individuals with allergies to plants in the Asteraceae/Compositae family (e.g., ragweed, daisies, marigolds, chrysanthemums). Symptoms of allergic reaction may include rash, hives, or difficulty breathing. If you experience any severe or persistent side effects, discontinue use and consult a healthcare professional. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Individuals with certain medical conditions should exercise caution or avoid milk thistle. If you have a known allergy to ragweed, chrysanthemums, marigolds, or daisies, you may also be allergic to milk thistle. People with hormone-sensitive conditions, such as breast, uterine, or ovarian cancer, endometriosis, or uterine fibroids, should be cautious because milk thistle may have estrogenic effects, although this is not definitively established. Always discuss any existing medical conditions or medications with your healthcare provider before starting milk thistle. Pregnant and breastfeeding women should avoid using milk thistle due to insufficient safety data. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Milk thistle is contraindicated for individuals with known hypersensitivity or allergy to milk thistle or other plants in the Asteraceae/Compositae family. It should also be avoided by pregnant and breastfeeding women due to a lack of sufficient safety data. Individuals with certain hormone-sensitive cancers or conditions should consult a healthcare professional before use due to potential estrogenic effects. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Milk thistle can interact with certain medications. It may affect how some drugs are broken down by the liver, potentially altering their effects or increasing their side effects. Key interactions include:
* **Cytochrome P450 (CYP450) Substrates:** Milk thistle may interact with drugs metabolized by the CYP450 enzyme system, including many prescription medications. This could potentially increase or decrease their levels in the body. Examples include some statins, anti-anxiety medications, and blood thinners.
* **Diabetes Medications:** Milk thistle may have blood sugar-lowering effects, potentially leading to hypoglycemia when combined with diabetes medications.
* **Estrogen-containing Medications:** Due to potential estrogenic effects, milk thistle might interact with birth control pills, hormone replacement therapy, or other estrogen-containing drugs.
* **Immunosuppressants:** There is some evidence that milk thistle could affect the activity of certain immunosuppressant drugs, such as sirolimus or tacrolimus.
Always consult your doctor or pharmacist about all medications and supplements you are taking before adding milk thistle to your regimen. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Milk thistle is typically taken orally. Given its potential to sometimes cause mild gastrointestinal upset, it is often recommended to take milk thistle supplements with food or meals. The standard dosage and frequency can vary based on the specific product and silymarin concentration, but it is typically taken once or twice daily. Users should follow the directions provided on the supplement label or as directed by a licensed clinician. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Put it into practice
Reading about Milk Thistle is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Milk Thistle?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any glp1 + supplement | Note | Category ruleConfidence: theoretical | GLP-1 medications slow stomach emptying, changing how/when oral supplements absorb; rapid weight loss raises the importance of protein and micronutrients.Source pending | Time oral supplements when nausea is lowest; prioritize protein and micronutrients; discuss with your provider. |
| Any supplement + medication | Note | Category ruleConfidence: theoretical | Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).Source pending | Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist. |
Frequently asked questions about Milk Thistle
The primary active ingredients in milk thistle are a group of flavonoid compounds collectively known as silymarin, which are extracted from the seeds of the plant.
While milk thistle is often used for liver support and protective effects, the evidence for its ability to reverse existing liver damage is limited and inconsistent. It is generally considered to support liver health and protect against further damage rather than being a cure for severe liver conditions. Always consult a healthcare professional for liver-related concerns.
The timeline for experiencing effects from milk thistle can vary widely among individuals and depends on the specific health concern being addressed. For some, improvements in symptoms or liver markers may be noticed within weeks to months, while for others, benefits may be more subtle or require longer-term use. Consistent use as directed is generally recommended to observe potential effects.
Milk thistle is generally considered safe for long-term use at recommended doses for most healthy individuals. However, long-term safety data, especially in specific populations or for all potential interactions, is still accumulating. It is always prudent to periodically review your supplement regimen with a healthcare professional, especially if you are using it long-term.
As a supplement, Milk Thistle can overlap with other supplements, prescription medicines, hormones and peptides. Because Milk Thistle is usually taken with a meal, most avoidable conflicts come from what else lands in that same window. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Milk Thistle with no sign-up.
Milk Thistle is typically taken with a meal. Published protocols usually have it taken with food. Amounts for this supplement vary by protocol, formulation and individual response, so follow the dose your clinician or the product label specifies.
Whether Milk Thistle fits alongside testosterone replacement therapy depends on the protocol — dose, ester and ancillaries such as HCG or anastrozole — and on current bloodwork. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
"Peptides" is not one category — healing peptides, GLP-1 agonists, growth-hormone secretagogues and melanocortins each behave differently next to Milk Thistle. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for Milk Thistle varies by protocol and formulation, so the label or prescription is what sets it. It is typically taken with a meal. Most protocols have it taken with food. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of Milk Thistle depends on the protocol and formulation you are on. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Milk Thistle the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
The cited randomized trial used silymarin (milk thistle extract) 420 mg or 700 mg three times daily in adults with nonalcoholic steatohepatitis. Route reported: Oral. Frequency reported: Three times daily in the cited trial. These are amounts documented in the cited studies and labels for Milk Thistle — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Milk Thistle?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Administration of silymarin in NAFLD/NASH: A systematic review and meta-analysis(opens PubMed in a new tab)Ann Hepatol · 2024 · PMID 38579127 · https://pubmed.ncbi.nlm.nih.gov/38579127/
- 2.Silymarin as Supportive Treatment in Liver Diseases: A Narrative Review(opens PubMed in a new tab)Adv Ther · 2020 · PMID 32065376 · https://pubmed.ncbi.nlm.nih.gov/32065376/
- 3.Milk thistle (Silybum marianum): A concise overview on its chemistry, pharmacological, and nutraceutical uses in liver diseases(opens PubMed in a new tab)Phytother Res · 2018 · PMID 30080294 · https://pubmed.ncbi.nlm.nih.gov/30080294/
- 4.Milk thistle in liver diseases: past, present, future(opens PubMed in a new tab)Phytother Res · 2010 · PMID 20564545 · https://pubmed.ncbi.nlm.nih.gov/20564545/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- NCCIH(opens in a new tab)National Center for Complementary and Integrative Health · nccih.nih.gov/health/milk-thistle
Verify at
Publisher search links for Milk Thistle. These are places to check the information — they are not citations, so they are not numbered.
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- PubChem(publisher search, opens in a new tab)National Center for Biotechnology Information · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed labeling archive(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Milk Thistle?
Plain-text summary, safe to quote verbatim:
Milk thistle (botanical name Silybum marianum) is a flowering herb related to the daisy and ragweed family. It is native to Mediterranean countries. Research on Milk Thistle focuses on healthy aging. It is typically taken with a meal. Dose, response, and interaction risk vary by individual, so use should be reviewed with a clinician.
Source: DoseRoutine — https://doseroutine.com/library/milk-thistle
Milk Thistle cheat sheet
DoseRoutine cheat sheet · Supplement
Milk Thistle
Milk thistle (botanical name Silybum marianum) is a flowering herb related to the daisy and ragweed family. It is native to Mediterranean countries.
Evidence
Moderate
One published human randomized trial; results not yet replicated.
Studied range
The cited randomized trial used silymarin (milk thistle extract) 420 mg or 700 mg three times daily in adults with nonalcoholic steatohepatitis
Route
Oral
Frequency studied
Three times daily in the cited trial
Half-life
Roughly 6 hours
Timing
with a meal
With food
with food
Storage
Room temperature, sealed, protected from light
Not FDA-approvedOTC supplementLongevity
Key references
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/milk-thistle
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Milk Thistle — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/milk-thistle
What compounds are similar to Milk Thistle?
Others in the supplement category or studied for the same goals.
Which goals is Milk Thistle used for?
Other compounds studied for the same benefits as Milk Thistle.
Continue exploring
See every compound DoseRoutine catalogs for these goals.