Turmeric liver injury

Turmeric used as a spice in normal amounts is not the concern. Treat any turmeric or curcumin supplement as an active product: stop it at once and see a doctor if you develop unexplained fatigue, nausea, stomach pain, dark urine, or yellowing of the eyes or skin, and never restart it after a reaction.

What it is

Turmeric is the yellow spice from the root of Curcuma longa; curcumin is the pigment behind most of its claimed effects. For years neither was linked to liver injury in any consistent way, and unformulated curcumin was well tolerated even at very high doses (8–12 g a day in dose-escalation studies), with some trials suggesting it may even lower liver enzymes.^[1] Making curcumin absorbable seems to have made liver harm more likely.

The US National Institutes of Health's LiverTox database now classifies turmeric and curcumin as a well-documented cause of clinically apparent liver injury, and as what appears to have become the most common cause of herbal-supplement liver injury in the US. Most cases involve high-absorption curcumin products. But piperine (black-pepper extract) was found in only 3 of the 7 products tested in the US case series, and LiverTox also describes cases with plain ground turmeric powder and even turmeric teas.^[2]

How common, and how serious

The injury is serious but rare: LiverTox says the true rate is unknown but probably very rare, roughly 1 in 10,000 to 1 in 100,000 people exposed.^[3] The defining US case series, from the Drug-Induced Liver Injury Network (DILIN), identified 10 patients over nearly two decades: 8 women, 9 with injury to the liver cells themselves (hepatocellular injury), latency 1–4 months, and one death.^[4] A one-author letter from a consultancy firm argued that the risk across the whole population is very low.^[5] A population-wide figure tempers the caution, but it does not dissolve it for the people actually taking these products.

Regulators have since acted. Health Canada, Italy, France and Australia have added liver-injury warnings or safety alerts for turmeric and curcumin supplements, and the US Pharmacopeia recommends a label warning that liver problems have been reported "very rarely". Health Canada notes that turmeric eaten as a spice in normal amounts is not a concern.^[6][7]

An immune reaction, not an overdose

• It is idiosyncratic, not dose-toxic. The injury is an immune-mediated reaction rather than simple overdose, which is why it is unpredictable. Health Canada describes the risk as "not dependent on the dose or duration of use", and a 2024 Spanish case involved only 120 mg of curcumin a day (with black pepper) for two months.^[8][9]
• There is a strong genetic risk marker. The HLA-B*35:01 immune-gene variant was carried by 7 of the 10 patients in the US case series,^[10] and LiverTox reports it in over 70% of cases versus 10–15% of people in comparison groups. That makes it the strongest known predictor of who is susceptible.^[11]
• Onset is delayed. Symptoms (fatigue, nausea and poor appetite, then dark urine and jaundice) typically appear after 1–4 months of continuous use. The liver enzyme alanine aminotransferase (ALT) can spike above 1,000 U/L, and the picture can mimic autoimmune hepatitis.
• It can be silent. In one small series of biopsied cases, about half the patients had no symptoms and were found only through abnormal blood tests.^[12]
• It usually resolves on stopping, within 1–3 months. But acute liver failure, liver transplants and deaths have occurred, mostly when people kept taking the product after symptoms began, and LiverTox estimates that roughly 1 in 10 people who develop jaundice might die. Anyone who has had this reaction should not take turmeric or curcumin again, because it can come back worse.^[13]

Why the intake limit doesn't settle it

The acceptable daily intake for curcuminoids, set by the WHO's Joint FAO/WHO Expert Committee on Food Additives (JECFA), is 0–3 mg per kilogram of body weight (about 210 mg for a 70-kg adult). It was established in 2004 and reaffirmed by the European Food Safety Authority (EFSA) in 2010. French and German food-safety agencies have warned that this limit was set for ordinary curcumin and may not protect people taking enhanced-absorption products, which may need lower limits set product by product.^[14][15] Doses commonly suggested for supplements, 500–1,000 mg of curcuminoids a day according to the UK's Committee on Toxicity, already run two to five times above that intake limit.^[16] And because the reaction does not appear to track dose, staying under any limit is no guarantee.

What to do

1. Turmeric used as a spice in normal amounts is not the concern. Supplements are.
2. Don't count on a short course to protect your liver. Avoid open-ended daily use, but don't treat an 8–12-week course as safe either: most reported reactions started 1–4 months in, so such a course sits squarely inside that window.^[17]
3. Stop at once and see a doctor if you notice unexplained fatigue, nausea, stomach pain, dark urine, or yellowing of the eyes or skin, and never take it again after a reaction.
4. If you have liver enzymes checked (ALT, aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT)), the useful times are before starting and within the first few months on a new product, because that is when most reactions appear. See Midlife labs.
5. Skip supplements if you have gallbladder or bile-duct problems (including gallstones), and check with a doctor first if you have current or past liver problems or take other medications.^[18]

For what curcumin does and doesn't do, its drug interactions and how to choose a product, see Curcumin.

Further reading

• Turmeric. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. NIH/NCBI Bookshelf.^[19]
• Halegoua-DeMarzio D et al. Liver Injury Associated with Turmeric — a Growing Problem: Ten Cases from the Drug-Induced Liver Injury Network. Am J Med 2023.^[20]
• Gupta SC et al. Therapeutic Roles of Curcumin: Lessons Learned from Clinical Trials. AAPS J 2013.^[21]