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Curcumin side effects: what is reported, and who should avoid it

Written by the Full Measure editorial team, which sells supplements. Approved for publication by the Full Measure owners. Updated .

Drafted with AI assistance from the sources listed below. How we write these

Quick answer

The most common side effects of turmeric by mouth are digestive upset such as nausea, vomiting and acid reflux. Liver injury has also been reported, mostly with high-absorption forms, and in ten US cases it began 1 to 4 months after starting. NCCIH says to stop and call a provider at signs such as dark urine or yellow skin.1,2,3

Key facts

  • NCCIH lists nausea, vomiting, acid reflux and stomach upset among the effects of turmeric taken by mouth, and hives or itching from curcumin on the skin.1
  • In ten US cases of liver injury linked to turmeric, 8 were women, 5 needed hospital care and 1 died of liver failure, and 7 carried the gene variant HLA-B*35:01.2
  • Single doses of 20, 40 and 80 mg of curcumin shrank the gallbladder by about 34%, 51% and 72% within 2 hours in healthy volunteers.4
  • Of 356 turmeric samples bought in markets in four South Asian countries, 14% had detectable lead.5
  • No tolerable upper intake level is set for turmeric or curcumin supplements.1,6

Digestive and skin reactions

Turmeric taken by mouth can cause nausea, vomiting, acid reflux, stomach upset, diarrhea or constipation.1

Curcumin applied to the skin can cause hives or itching, and contact dermatitis has been reported.1,7

These effects are the ones NCCIH names for turmeric in ordinary amounts. In an early dose-escalation study of 24 healthy volunteers given single doses of 500 to 12,000 mg, only 7 had minimal side effects, and they did not rise with the dose.1,8

Liver injury

The liver is the serious concern. The figures below come from NIH's liver injury database and from published case series, which show that injury happens but cannot show how often.2,3,9

Liver injury has been reported with turmeric and curcumin products, mostly highly bioavailable formulations. NIH's LiverTox database counts several dozen cases of acute liver injury, along with a low rate of short-lived rises in liver enzymes.1,3,9

In ten US cases, liver injury began 1 to 4 months after starting turmeric. Eight of the ten were women, five needed hospital care and one died of liver failure, and seven carried the gene variant HLA-B*35:01.2

In Tuscany, seven cases of acute liver injury were all linked to products with high bioavailability and high curcumin doses, and most people recovered after stopping. Together with 23 published cases, that is why NCCIH warns specifically about highly bioavailable forms.1,3

In US survey data from 2017 to 2020, turmeric products were the most used of six botanicals that have been linked to liver injury.10

NCCIH advises stopping turmeric or curcumin and talking with a health care provider at any sign of liver damage, such as tiredness, nausea, poor appetite, dark urine or yellowing of the skin or eyes.1

Gallbladder and kidney stones

Curcumin makes the gallbladder contract: in healthy volunteers, single doses of 20, 40 and 80 mg shrank it by about 34%, 51% and 72% within 2 hours.4

We therefore ask anyone with gallstones or a blocked bile duct to check with a doctor first. The doses in that study were small, from 20 to 80 mg of curcumin, and we found no study of whether the spice in food does the same.1,4

Supplemental turmeric raised urinary oxalate in healthy adults, which the researchers said could raise the risk of kidney stones in people prone to them.11

Blood-thinning medicines and sugar

NIH's breastfeeding database notes that turmeric may increase the risk of bleeding in people taking warfarin or antiplatelet drugs. The warfarin label asks for more frequent INR checks whenever a botanical is started or stopped.7,12

Ask your pharmacist whether any change in your regular medicines needs extra monitoring. The warfarin label does not name turmeric, but it asks for more frequent INR checks whenever a botanical is started or stopped.12

In one 12-week trial in adults aged 50 to 80, blood glucose was higher with a solid lipid curcumin product than with placebo.13

Contamination, pregnancy and how much

Some turmeric spice sold in South Asia has been adulterated with lead chromate to brighten its color: 14% of 356 market samples from four countries had detectable lead.5

NCCIH says the use of turmeric supplements during pregnancy may be unsafe, and that little is known about amounts above those in food while breastfeeding.1

No tolerable upper intake level is set for turmeric or curcumin supplements. For curcumin used as a food color (E 100), the European Food Safety Authority applies an acceptable daily intake of 3 mg per kg of body weight a day, about 210 mg for a 70 kg adult.6

Who should ask first

  • Anyone with liver disease, or who has had liver trouble with a supplement1,9
  • Anyone taking warfarin, another blood thinner or an antiplatelet medicine7,12
  • Anyone with gallstones or a blocked bile duct, or who has had kidney stones4,11
  • Anyone pregnant, trying to become pregnant or breastfeeding1,7
  • Anyone taking a prescription medicine, as NCCIH advises asking your provider before combining herbs and medicines1
  • Anyone being treated for cancer, who should tell their care team about every supplement1

Questions people ask

Is curcumin safe to take daily?

NCCIH calls conventionally formulated turmeric or curcumin likely safe in recommended amounts for up to 2 or 3 months. Liver injury has been reported, mostly with high-absorption products, so ask your doctor before taking it daily for longer.1,3

What are the turmeric side effects for women?

No source we read lists effects that differ by sex. Eight of the ten US liver injury cases linked to turmeric were in women, but a small registry series cannot show that women are more at risk. NCCIH says supplements may be unsafe in pregnancy.1,2

What are the turmeric side effects for men?

We found none specific to men. The effects NCCIH lists for turmeric by mouth are digestive, and 2 of the 10 US liver injury cases were men. Ask your doctor first if you take warfarin or another blood thinner.1,2,7

When should I stop taking curcumin?

NCCIH advises stopping turmeric or curcumin products immediately and talking with a health care provider at any sign of liver damage, such as fatigue, nausea, poor appetite, dark urine or jaundice.1

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Sources

  1. National Center for Complementary and Integrative Health. Turmeric. Bethesda (MD): National Institutes of Health. Last updated April 2025. Opened 2026-10-07.
  2. Halegoua-DeMarzio D, Navarro V, Ahmad J, et al. Liver Injury Associated with Turmeric: A Growing Problem. Ten Cases from the Drug-Induced Liver Injury Network [DILIN]. Am J Med. 2023;136(2):200-206. Opened 2026-10-07.
  3. Lombardi N, Crescioli G, Maggini V, et al. Acute liver injury following turmeric use in Tuscany: An analysis of the Italian Phytovigilance database and systematic review of case reports. Br J Clin Pharmacol. 2021;87(3):741-753. Opened 2026-10-07.
  4. Rasyid A, Rahman AR, Jaalam K, Lelo A. Effect of different curcumin dosages on human gall bladder. Asia Pac J Clin Nutr. 2002;11(4):314-318. Opened 2026-10-07.
  5. Forsyth JE, Mistree D, Nash E, Angrish M, Luby SP. Evidence of turmeric adulteration with lead chromate across South Asia. Sci Total Environ. 2024;949:175003. Opened 2026-10-07.
  6. European Food Safety Authority. Refined exposure assessment for curcumin (E 100). EFSA J. 2014;12(10):3876. Opened 2026-10-07.
  7. Turmeric. In: Drugs and Lactation Database (LactMed). Bethesda (MD): National Institute of Child Health and Human Development; 2006 onward. Updated July 15, 2025. Summary read through PubMed. Opened 2026-10-07.
  8. Lao CD, Ruffin MT 4th, Normolle D, et al. Dose escalation of a curcuminoid formulation. BMC Complement Altern Med. 2006;6:10. Opened 2026-10-07.
  9. Turmeric. In: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012 onward. Updated June 16, 2025. Summary read through PubMed. Opened 2026-10-07.
  10. Likhitsup A, Chen VL, Fontana RJ. Estimated Exposure to 6 Potentially Hepatotoxic Botanicals in US Adults. JAMA Netw Open. 2024;7(8):e2425822. Opened 2026-10-07.
  11. Tang M, Larson-Meyer DE, Liebman M. Effect of cinnamon and turmeric on urinary oxalate excretion, plasma lipids, and plasma glucose in healthy subjects. Am J Clin Nutr. 2008;87(5):1262-1267. Opened 2026-10-07.
  12. Warfarin sodium tablets: prescribing information (Amneal Pharmaceuticals). DailyMed, U.S. National Library of Medicine. Published June 3, 2026. Opened 2026-10-07.
  13. Cox KHM, White DJ, Pipingas A, Poorun K, Scholey A. Further Evidence of Benefits to Mood and Working Memory from Lipidated Curcumin in Healthy Older People: A 12-Week, Double-Blind, Placebo-Controlled, Partial Replication Study. Nutrients. 2020;12(6):1678. Opened 2026-10-07.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.