Silymarin
Silymarin reliably modestly lowers ALT and AST in fatty liver disease and shows credible glucose-lowering effects in T2D. The most clinically dramatic use is IV silibinin in Amanita mushroom poisoning. Oral bioavailability is poor — phytosomal formulations matter when therapeutic intent is serious.
Quick decision guide
May help most
Adults with NAFLD/MASLD, alcohol-related liver enzyme elevation, drug-induced liver enzyme rises (chemo, isoniazid), or T2D as an adjunct to standard care. Hospital IV use for Amanita phalloides poisoning.
Common dosing range
200–600 mg/day standardized silymarin (80% flavonolignans), split into 2–3 doses with meals.
When to expect effects
8–12 weeks for liver enzyme reductions; weeks–months for glycemic effects.
Watch out for
Coordinate with prescribers if on hepatically-metabolized drugs, warfarin, sirolimus, or hormone-sensitive cancer treatment.
Evidence snapshot
What is it
Silymarin is the bioactive flavonolignan complex extracted from milk thistle (Silybum marianum) seeds. It is composed primarily of silybin (also called silibinin), isosilybin, silychristin, and silydianin, with silybin accounting for roughly 60 to 70 percent of total activity.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
Amanita phalloides (death cap) mushroom poisoning Good Evidence | Improved survival vs historical controls when started early; observational data only | Hospitalized patients with confirmed or suspected Amanita phalloides ingestion within 48 hours — IV silibinin under critical-care supervision | Hours — earlier is better; outcomes worsen rapidly after 48 hours |
NAFLD / MASLD — liver enzyme reduction Good Evidence | ~17 IU/L ALT and ~12.5 IU/L AST reduction over 8–12 weeks at 200–600 mg/day | Adults with biopsy- or imaging-confirmed NAFLD/MASLD and elevated transaminases | 8–12 weeks |
Type 2 diabetes glycemic control Limited Evidence | ≈27 mg/dL fasting glucose reduction; ≈1.07% HbA1c reduction in T2D over weeks–months | Adults with T2D on stable standard therapy who want a low-risk adjunct | 45–90 days |
Alcohol-related liver disease Limited Evidence | Inconsistent across trials; modest at best | Adults in recovery from alcohol use disorder with persistent transaminase elevation | Months |
Drug-induced liver injury (adjunct) Limited Evidence | Variable reductions in chemo/INH-induced ALT elevation in small RCTs | Patients on hepatotoxic regimens (TB therapy, certain chemo) at known risk for transaminitis — coordinate with oncologist or infectious-disease physician | Weeks to months |
Chronic viral hepatitis (B / C) Mixed Evidence | Small ALT changes; no impact on viral load or fibrosis | Historical interest only; modern DAA therapy is the standard of care | Months |
Amanita phalloides (death cap) mushroom poisoning
- Effect
- Improved survival vs historical controls when started early; observational data only
- Best fit
- Hospitalized patients with confirmed or suspected Amanita phalloides ingestion within 48 hours — IV silibinin under critical-care supervision
- Time
- Hours — earlier is better; outcomes worsen rapidly after 48 hours
NAFLD / MASLD — liver enzyme reduction
- Effect
- ~17 IU/L ALT and ~12.5 IU/L AST reduction over 8–12 weeks at 200–600 mg/day
- Best fit
- Adults with biopsy- or imaging-confirmed NAFLD/MASLD and elevated transaminases
- Time
- 8–12 weeks
Type 2 diabetes glycemic control
- Effect
- ≈27 mg/dL fasting glucose reduction; ≈1.07% HbA1c reduction in T2D over weeks–months
- Best fit
- Adults with T2D on stable standard therapy who want a low-risk adjunct
- Time
- 45–90 days
Alcohol-related liver disease
- Effect
- Inconsistent across trials; modest at best
- Best fit
- Adults in recovery from alcohol use disorder with persistent transaminase elevation
- Time
- Months
Drug-induced liver injury (adjunct)
- Effect
- Variable reductions in chemo/INH-induced ALT elevation in small RCTs
- Best fit
- Patients on hepatotoxic regimens (TB therapy, certain chemo) at known risk for transaminitis — coordinate with oncologist or infectious-disease physician
- Time
- Weeks to months
Chronic viral hepatitis (B / C)
- Effect
- Small ALT changes; no impact on viral load or fibrosis
- Best fit
- Historical interest only; modern DAA therapy is the standard of care
- Time
- Months
Evidence for 6 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
Amanita phalloides (death cap) mushroom poisoning
Disease adjunctIV silibinin (Legalon SIL) is standard adjunctive treatment for Amanita phalloides poisoning across Europe and available in the US via expanded access. It competitively inhibits hepatocyte uptake of amatoxins via OATP1B3. Case series — including the 2013 Australian cohort using 5 mg/kg IV bolus then 20 mg/kg/day infusion — report better outcomes when started within 48 hours of ingestion. Despite treatment, mortality from amatoxin poisoning remains substantial; no formal RCT exists (and ethically can't).
Bottom line: Hospital IV use only — if you've eaten a wild mushroom and feel ill, go to the ER. Do not rely on oral silymarin for this.
NAFLD / MASLD — liver enzyme reduction
Biomarker supportA 2024 meta-analysis of 9 RCTs in metabolic dysfunction-associated steatotic liver disease (MASLD/NAFLD) found silymarin reduced ALT by ~17 IU/L and AST by ~12.5 IU/L vs placebo, with a modest triglyceride reduction. Effects on body weight and fasting glucose did not reach significance. Lifestyle change (weight loss, alcohol reduction) remains the cornerstone — silymarin is an adjunct, not a substitute.
Bottom line: Real but biomarker-level benefit. Use as an adjunct to weight loss and dietary change, not in their place.
Type 2 diabetes glycemic control
Supplement benefitA 2018 meta-analysis of 7 RCTs (Hadi et al.) found silymarin reduced fasting glucose by ~27 mg/dL and HbA1c by ~1.07% in adults with T2D. Effect sizes are large for an adjunct supplement but study quality and heterogeneity limit confidence; the authors explicitly caution against making firm recommendations. Most trials used 200–600 mg/day for 45–90 days.
Bottom line: Promising signal worth a 3-month trial with HbA1c monitoring; don't dose-reduce your prescribed diabetes meds without prescriber input.
Evidence is mixed
Effect size is implausibly large for a single adjunct supplement, and authors of the meta-analysis explicitly caution that low study quality and heterogeneity prevent firm recommendations.
Alcohol-related liver disease
Disease adjunctTrials in alcoholic liver disease are mixed: some show ALT/AST reductions and modest survival benefit in cirrhosis, others show no clear effect. The overriding determinant of outcome is alcohol cessation; silymarin without that is largely irrelevant. Reasonable to use as an adjunct after sobriety is established and liver function still shows enzyme elevation.
Bottom line: Useful only after you stop drinking. The supplement can't outwork ongoing alcohol exposure.
Drug-induced liver injury (adjunct)
Disease adjunctSmall RCTs of silymarin alongside isoniazid (TB treatment) and certain chemotherapy regimens report reduced ALT/AST elevations vs placebo. Evidence is mixed and trials are small. Doesn't replace dose-adjustment or treatment-discontinuation decisions made by the prescriber.
Bottom line: An adjunct, not a rescue. Talk to your prescriber before adding it to chemotherapy or TB therapy.
Chronic viral hepatitis (B / C)
Disease adjunctOlder trials of oral silymarin in chronic hepatitis B/C showed variable, mostly modest effects on transaminases and quality of life, but no clinically meaningful effect on viral load or fibrosis progression in well-conducted trials. Modern direct-acting antivirals (DAAs) for HCV produce >95% cure rates and entirely supersede silymarin's role here.
Bottom line: Modern antivirals cure HCV; silymarin can't. Don't use it as a substitute.
How it works
How to take it
What to track
Bottom line: 200–600 mg/day split across meals, plus a phytosomal format if you want stronger bioavailability. Recheck liver labs at 8–12 weeks.
5 commercial forms
Compare the main delivery options and what they’re best suited for.
Standardized silymarin extract (80% flavonolignans)
Most commonThe standard consumer form, typically 80% total silymarin with ~30–40% silybin within that. Most cost-effective; oral bioavailability is intrinsically low so doses need to be 200–600 mg/day.
Low oral absorption (~23–47%); short plasma half-life.
Silybin phytosome (Siliphos / silybin-phosphatidylcholine)
Better absorbedSilybin bound to phosphatidylcholine, which increases plasma silybin 5–10× vs standard extract. Preferred for serious therapeutic intent (NAFLD, T2D, chemo adjunct). Comparable activity at ~half the dose of standard silymarin.
5–10× higher plasma silybin vs standardized extract.
High-purity silybin (silibinin) isolate
Pharmaceutical-gradeConcentrated single-isomer silybin. Used in research and in Legalon SIL (IV form for Amanita poisoning). Higher per-gram activity but no clear oral-bioavailability advantage over standardized silymarin.
Same oral absorption limitations as silymarin unless phytosomal.
IV silibinin (Legalon SIL)
Hospital onlyIntravenous silibinin dihemisuccinate for Amanita phalloides poisoning. Used in expanded-access protocols in the US and routinely in Europe. Not available OTC.
100% bioavailability (IV); the only form effective for amatoxin poisoning.
Whole milk thistle seed / tea
Traditional, weakGround seeds or tea preparations. Total silymarin content is low and inconsistent. Fine as a beverage; not a substitute for standardized extracts when therapeutic effect matters.
Variable; therapeutic dose hard to reach from tea alone.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Allergic reactions (mouth itching, tongue swelling, hives, anaphylaxis in rare cases) — especially in people allergic to ragweed/daisies/chrysanthemums (Asteraceae family).
Case-level reports of severe nosebleeds and bullous pemphigoid have appeared in long-term users.
Theoretical mild estrogenic effect — relevant for hormone-sensitive cancers (breast, endometrial); discuss with oncologist before use.
Who should avoid it
- People with Asteraceae plant allergies (ragweed, daisies, chrysanthemums, marigolds).
- Solid organ transplant recipients on sirolimus or similar immunosuppressants without transplant-team approval.
- People on warfarin or other narrow-therapeutic-index hepatically metabolized drugs without prescriber coordination.
- People with hormone-sensitive cancers (breast, endometrial, prostate) without oncologist input.
Pregnancy & breastfeeding
Human safety data in pregnancy are limited. Small case series have used silymarin for intrahepatic cholestasis of pregnancy with apparently uneventful outcomes. Animal studies at high doses have reported fetal weight reduction and some malformations, but human-equivalent doses have not been systematically studied. Generally avoid in pregnancy unless prescribed for cholestasis under specialist care; breastfeeding data are sparse but case reports do not show serious infant adverse events.
Bottom line: Most people tolerate it well. The interaction list is what to watch — coordinate with prescribers if you're on warfarin, sirolimus, antipsychotics, or hormone-sensitive cancer therapy.
Interactions
Reports of increased sirolimus levels and toxicity in transplant recipients on milk thistle. Avoid unless transplant team approves and monitors levels.
Documented case of INR rising from 2.64 to 4.12 with milk thistle co-administration. Mechanism may involve CYP2C9 inhibition or displacement. Monitor INR more frequently if starting or stopping silymarin.
Seven case reports of pancreatitis in patients taking milk thistle alongside antipsychotics. Avoid combination or monitor closely.
Silymarin lowers fasting glucose and HbA1c in T2D. Additive hypoglycemia risk with insulin or sulfonylureas — monitor blood sugar more frequently and adjust doses with your prescriber.
In vitro CYP3A4 inhibition by silymarin could raise statin levels and muscle-toxicity risk. Clinical data are inconsistent; discuss with prescriber, especially at higher silymarin doses.
Theoretical mild estrogenic activity could interfere with anti-estrogen breast-cancer therapy. Avoid in hormone-sensitive cancer without oncology approval.
A formal PK study (Piscitelli) showed minimal effect of milk thistle on indinavir pharmacokinetics. Routine avoidance not necessary; mention to your HIV team.
Protocols featuring Silymarin
Evidence-backed routines where Silymarin plays a role.
Food sources
| Food | Amount | %DV |
|---|---|---|
| Milk thistle seeds (whole or ground) | Not typically eaten as food; precursor for extracts | — |
| Artichoke (related to milk thistle, contains some flavonolignans) | 1 medium artichoke (some related polyphenols, not silymarin) | — |
Milk thistle seeds (whole or ground)
- Amount
- Not typically eaten as food; precursor for extracts
- %DV
- —
Artichoke (related to milk thistle, contains some flavonolignans)
- Amount
- 1 medium artichoke (some related polyphenols, not silymarin)
- %DV
- —
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
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Frequently asked questions
Is silymarin the same as milk thistle?⌄
Silymarin is the active flavonolignan complex extracted from milk thistle seeds. Milk thistle products are typically standardized to a specific silymarin content (often 80 percent). When you take a silymarin supplement, you're effectively taking a concentrated form of the active part of milk thistle.
What's the difference between silymarin and silybin?⌄
Silymarin is the complex of related flavonolignans (silybin, isosilybin, silychristin, silydianin). Silybin is the single most active component, accounting for 60 to 70 percent of silymarin's activity. Some products isolate silybin specifically; most contain the full silymarin complex.
Why is silymarin absorbed so poorly?⌄
Silybin is poorly water-soluble and is rapidly conjugated and excreted by the liver after absorption. The result is low and brief plasma levels. Phytosomal formulations (silybin + phosphatidylcholine) substantially improve absorption.
How long until I see effects?⌄
Changes in liver enzymes typically appear over 8 to 12 weeks of consistent daily dosing. Don't expect immediate effects.
Can silymarin reverse liver damage?⌄
Silymarin may reduce liver enzyme markers of ongoing damage and modestly support liver function, but it does not reverse established cirrhosis or chronic damage. Stopping the underlying insult (alcohol, hepatotoxic drugs, viral infection) is far more important than any supplement.
References by claim
NAFLD / MASLD — liver enzyme reduction
Hashemi et al., 2024 — PubMed — meta-analysis on MASLD/NAFLD (2024) link
Type 2 diabetes glycemic control
Hadi et al., 2018 — PubMed — Complementary Therapies in Medicine (2018) link
Amanita phalloides (death cap) mushroom poisoning
Chronic viral hepatitis (B / C)
MSKCC Integrative Medicine — Milk Thistle — Memorial Sloan Kettering Cancer Center (2024) link
Track Silymarin with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.