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Supplements and Your Liver: Which Ones Can Harm It, What Helps Fatty Liver, and the Warning Signs

Yes, some popular supplements can damage the liver. Green tea extract, turmeric, garcinia, ashwagandha, kava, slow-release niacin and bodybuilding products have all caused liver injury in published case reports, registry cases or trials, occasionally needing a transplant. No pill is shown to keep a healthy liver healthy. For fatty liver, weight loss matters most; vitamin E improved liver biopsies in adults without diabetes (grade B). If your skin or eyes turn yellow, stop it and get medical care.

Published How we grade evidenceEditorial policy

The short version

  • Supplements are a growing cause of drug-related liver injury: their share of cases in a US liver-injury registry climbed from 7% to 20% over 2004 to 2013 (Navarro 2014).
  • In a 12-month trial of 1,021 women, high-dose green tea extract pushed up liver enzymes. Grade B (Yu 2017).
  • Turmeric, garcinia and ashwagandha have each caused serious liver injury in published case series, including deaths. Grade C (Halegoua-DeMarzio 2023; Vuppalanchi 2022; Björnsson 2020; Philips 2023).
  • For fatty liver, weight loss comes first: 90% of people who lost at least 10% of their weight saw their liver inflammation resolve (Vilar-Gomez 2015).
  • Vitamin E improved liver biopsies in adults with NASH and no diabetes. Grade B (Sanyal 2010).
  • Milk thistle lowers liver blood tests but did not meet its main biopsy goal. Grade B for blood tests (Li 2024).

Your liver clears most of what you swallow, which is why it takes the hit when a product goes wrong. In the most recent 20-year update of the same registry, supplements kept growing as a share of cases (Fontana 2026). And an estimated 15.6 million US adults used at least one of six botanicals most often tied to liver injury in a single month (Likhitsup 2024). Here is which ones, what to watch for, and what actually helps.

Can supplements cause liver damage?

Yes. The US Drug-Induced Liver Injury Network (DILIN) tracks severe liver injury from medicines and supplements. Of 839 cases from 2004 to 2013, 130 were caused by supplements. Bodybuilding products mainly caused long-lasting jaundice in young men. Other supplements more often led to death or a liver transplant than medicines did: 13% of cases vs 3% (Navarro 2014). Registries like this are how problems with supplements come to light. Doctors look products up in LiverTox, the US government's liver-injury database.

ProductWhat happenedEvidence
Green tea extract pillsEnzyme rises in a trial; injury in case reportsOne large trial plus case reports
Turmeric or curcuminHepatitis, one death, in 10 registry casesCase series
Garcinia (often with green tea)Severe injury in 22 cases, one death, one transplantCase series
AshwagandhaJaundice and itching lasting weeks; deaths in people with liver diseaseCase series
KavaRare but sometimes fatal injuryCase reports
Slow-release niacinLiver toxicity in half of trial patients at high dosesOne small trial
Bodybuilding productsSevere jaundice, often from hidden steroidsCase series

Is green tea extract bad for your liver?

Grade B that high-dose pills can be. In a trial of 1,021 women with normal liver tests, a year of high-dose green tea extract capsules raised the liver enzyme ALT, and 5.1% developed moderate or worse liver test changes, with odds about 7 times those on placebo. Levels fell when women stopped and rose again when they restarted (Yu 2017). Case reports involve 140 to about 1,000 mg a day of EGCG, the main green tea catechin, and fasting doses are absorbed more. The US Pharmacopeia's label advice is to take it with food and to avoid it if you have a liver problem (Oketch-Rabah 2020). Green tea as a drink has no reported safety concerns in adults (NCCIH). See our green tea extract page.

Can turmeric damage your liver?

Grade C from case series, and the signal is growing. DILIN found 10 turmeric cases, all since 2011 and 6 since 2017. Most were women; 5 were hospitalized and 1 died of liver failure. Injury showed up 1 to 4 months after starting, 3 of the products tested had black pepper extract added (piperine, which helps the body take up more), and 7 of the 10 people carried a gene variant, HLA-B*35:01 (Halegoua-DeMarzio 2023). NCCIH warns that highly absorbable curcumin products may harm the liver (NCCIH). The cases involved supplements, not turmeric used in cooking. See our curcumin page.

Is ashwagandha bad for your liver?

Grade C. Liver injury is rare but documented. In 5 cases from Iceland and the US, people developed jaundice, nausea, tiredness and itching 2 to 12 weeks after starting; it cleared within 1 to 5 months, with no liver failure (Björnsson 2020). In India, 8 people had injury from single-ingredient products; 3 people with existing chronic liver disease went into liver failure and died (Philips 2023). If you have liver disease, avoid it. See our ashwagandha for stress guide.

What about garcinia, kava, niacin and bodybuilding products?

  • Garcinia cambogia: 22 registry cases, alone or with green tea, in people aged 17 to 54; 91% were hospitalized, 1 died and 1 needed a transplant (Vuppalanchi 2022). It is sold mainly for weight loss.
  • Kava: linked to rare cases of liver injury that were sometimes serious or fatal (NCCIH). Risk factors included high doses, long use and taking other remedies with it (Teschke 2008). See our kava page.
  • Slow-release niacin: in a trial that raised doses from 500 to 3,000 mg a day, 12 of 23 people on the sustained-release form developed liver toxicity, against none on the immediate-release form (McKenney 1994). Upper limit for adults: 35 mg a day from supplements; take more only with blood tests or your clinician's advice (NIH ODS).
  • Bodybuilding products: 44 young men developed deep jaundice, 84% with itching, and 71% were hospitalized; some products held anabolic steroids that were not on the label (Stolz 2019).
  • Red yeast rice: contains monacolins that work like a cholesterol drug. Serious liver or muscle reactions are reported but very rare; a European food-safety panel found significant safety concerns at 10 mg of monacolins a day, with serious cases at doses as low as 3 mg (Banach 2023).
  • Vitamin A: a person taking 25,000 IU a day from a supplement developed severe liver damage (Kowalski 1994). Upper limit for adults: 10,000 IU (3,000 mcg) of preformed vitamin A a day; take more only with blood tests or your clinician's advice (NIH ODS).

What are the signs of liver damage from supplements?

Watch for yellow skin or eyes (jaundice), dark urine, itching, pain in the upper belly, nausea, poor appetite and unusual tiredness (Oketch-Rabah 2020; Björnsson 2020; NCCIH). In the registry cases, symptoms usually started weeks to a few months after a product was begun, with a median of 51 days for garcinia (Vuppalanchi 2022). If you notice them, stop the product and get a liver blood test (NCCIH).

What is the best supplement for liver health?

For a healthy liver, no supplement has been shown to help. Of the 20 best-selling online "liver cleanse" products, 19 contained milk thistle, and the evidence behind their ingredients was limited and inconclusive (Telbany 2026). For fatty liver disease (MASLD, formerly NAFLD), weight loss does the most: in 293 people with liver inflammation (NASH), losing 5% of body weight resolved it in 58%, and losing 10% or more resolved it in 90% (Vilar-Gomez 2015). Coffee drinkers have lower rates of fatty liver in observational studies, which cannot prove cause. Grade C (Chen 2019). See our fatty liver findings.

Does vitamin E help fatty liver?

Grade B, for one group: adults with NASH who do not have diabetes. In the PIVENS trial of 247 such adults, 800 IU a day for 96 weeks improved liver biopsies in 43% vs 19% on placebo, though scarring did not improve (Sanyal 2010). A 2025 trial in 124 adults found 300 mg a day improved biopsies in 29.3% vs 14.1% (Song 2025). A Cochrane review of 16 trials in children and adults found vitamin E likely lowers liver enzymes slightly, but its effect on long-term health and safety is unknown (Wen 2024). Use it only with your doctor's oversight, because of the risks below. See our vitamin E page.

Does milk thistle help your liver?

Grade B for lower liver blood tests, Grade C for biopsy changes. Pooling 26 trials (2,375 people) with fatty liver, silymarin, the extract of milk thistle, lowered liver enzymes and liver fat scores, and the authors call for confirmation (Li 2024). In a biopsy trial, 99 adults with NASH took 700 mg three times a day or placebo for 48 weeks; the extract missed its main goal, though more people had less scarring (Wah Kheong 2017). In alcohol-related and hepatitis B or C liver disease, milk thistle did not lower deaths across 18 trials (Rambaldi 2007). See our milk thistle page.

Do fish oil, berberine or curcumin help fatty liver?

  • Fish oil (omega-3): across 20 trials, no change in liver fat on MRI, liver stiffness or biopsy; a small improvement on ultrasound and in one liver enzyme (GGT) may reflect publication bias; more side effects than control. Grade B (Kim 2025).
  • Berberine: lowered liver enzymes and blood fats in 10 trials (811 people), with mild stomach side effects. Grade B (Nie 2024). If you take metformin, see can I take berberine with metformin?
  • Curcumin: lowered liver enzymes a little in trials mostly from two countries. Grade C (Lukkunaprasit 2023). Weigh that against the liver injury cases above.

What we'd skip

  • "Liver cleanse" blends. Their ingredients have limited, inconclusive evidence (Telbany 2026), and some mix in turmeric, a known cause of injury (Halegoua-DeMarzio 2023).
  • Garcinia and green tea weight-loss pills. Severe injury, a death and a transplant in 22 registry cases (Vuppalanchi 2022).
  • Bodybuilding "muscle builders." Hidden steroids and deep jaundice in 44 men (Stolz 2019).
  • Slow-release niacin bought on your own. Liver toxicity in about half of trial users at high doses (McKenney 1994).
  • Ashwagandha or kava if you have liver disease. Deaths in people with existing liver disease (Philips 2023; NCCIH).

Safety and interactions

When to see a doctor

  • Same day: yellowing of the skin or eyes, or dark urine, after starting any supplement. Stop the product and take the bottle with you; in the registry cases, products were tested to confirm what was in them (Halegoua-DeMarzio 2023).
  • Soon: itching, upper-belly pain, nausea or deep tiredness that starts within a few months of a new product.
  • Before starting: any of the products above if you have liver disease, drink heavily, or take medicines that affect the liver.

Don't stop a prescribed medicine on your own; ask the prescriber or pharmacist. If you are pregnant, breastfeeding or under 18, ask a clinician.

FAQ

Which supplements are bad for your liver? Green tea extract pills, turmeric or curcumin, garcinia, ashwagandha, kava, slow-release niacin, high-dose vitamin A and bodybuilding products have all caused liver injury in published cases.

Is turmeric bad for your liver? Turmeric supplements caused hepatitis in 10 US registry cases, including one death, usually 1 to 4 months after starting (grade C). The cases involved supplements, not turmeric in cooking.

What are the signs of liver damage from supplements? Yellow skin or eyes, dark urine, itching, upper-belly pain, nausea, poor appetite and unusual tiredness. Stop the product and see a doctor.

What is the best supplement for liver health? No supplement is shown to help a healthy liver. For fatty liver, weight loss helps most, and vitamin E improved biopsies in adults with NASH and no diabetes (grade B).

Does milk thistle help your liver? It lowers liver blood tests in people with fatty liver (grade B), but it missed its main goal in a biopsy trial and did not lower deaths in alcohol or hepatitis liver disease.

Sources

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