Turmeric (curcumin)

Is turmeric safe?

Two answers. Turmeric the spice, at the amounts used in cooking, is safe for almost everyone. Turmeric and curcumin supplements are different products: they deliver tens to hundreds of times more curcumin, often with black pepper extract or other tricks to boost absorption. Those supplements have become one of the most frequently reported herbal causes of liver injuryDrug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary in the US and Europe.

The risk for any one person is low. But the cases are serious enough, and consistent enough, that regulators on four continents have acted. The NIH complementary health centre now says conventional turmeric is likely safe at recommended amounts for 2 to 3 months, while warning that liver damage has been reported with high-bioavailability formulations.

The liver injury pattern

In 2023, researchers from the US Drug-Induced Liver InjuryDrug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary Network (DILIN) described ten patients with liver injury linked to turmeric, six of them since 2017. The injury was usually hepatocellular (damage to liver cells themselves), appeared 1 to 4 months after starting, and in some cases was severe. Seven of the ten carried a gene variant, HLA-B*35:01, found in only about 6% to 7% of the general population. The same variant has been linked to liver injury from green tea extract.

The genetic link matters. It suggests an immune reaction in susceptible people rather than a straightforward overdose, which is why the injury is unpredictable and why standard dose limits cannot fully remove the risk.

Other countries have seen the same signal:

• Italy, 2019: about 20 cases of acute cholestatic hepatitis linked to turmeric supplements in a few months.
• France: by 2021 the food safety agency ANSES had more than 100 adverse event reports, 15 of them hepatitis.
• Australia: the TGA received 18 liver reports up to June 2023, and in four cases turmeric or curcumin was the only plausible cause. One person died.
• Canada: a 2025 Health Canada review found 12 Canadian cases and more than 60 international reports.

Stop the supplement and see a doctor if you notice yellow skin or eyes, dark urine, itching, abdominal pain or unusual tiredness.

Why absorption enhancers are the concern

Plain curcumin is poorly absorbed: most passes straight through the gut. That once seemed reassuring. Manufacturers have since added piperine (from black pepper), formulated curcumin with fats or nanoparticles, or bound it to other molecules, raising blood levels many times over. Germany's BfR, France's ANSES and Australia's TGA have all said the liver risk may be higher with these enhanced-absorption products. ANSES set a maximum of 153 mg of curcumin a day for a 60 kg adult in 2022, which many supplements exceed in a single capsule.

Interactions

Curcumin has a mild anti-platelet effect and may affect drug-metabolising enzymes. There are case reports of raised INR in people taking warfarin. Tell your doctor or pharmacist if you take anticoagulants, antiplatelet drugs, diabetes medicines or chemotherapy. Combining turmeric with fish oil or ginkgo adds to the bleeding effect.

Quality and adulteration

Turmeric's colour makes it a target for fraud. Stanford researchers showed in 2019 that some turmeric in Bangladesh had been coloured with lead chromate, a yellow pigment, and lead-contaminated turmeric has been recalled in the US. Supplements carry their own risks: curcumin content varies widely, some contain synthetic curcumin, and enhancer content is rarely standardised. If you choose to take one, look for a USP VerifiedThird-party testingTesting of a supplement by an independent lab to check that it contains what the label says and is free of set contaminants.More in the glossary mark and a stated curcumin dose, and avoid multi-ingredient "detox" or "liver support" blends.

Who should avoid curcumin supplements

• People with liver disease, gallstones or bile duct problems. Italy's warning label names these groups.
• People on blood thinners, unless their doctor agrees.
• Pregnant or breastfeeding women: food amounts are fine, but supplement doses have not been studied.
• Anyone who has had liver injuryDrug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary from another herbal product, such as green tea extract.

How we scored it

Organ toxicity (52) is the weakest factor because serious liver injuryDrug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary reports keep accumulating across countries. Regulatory actions (55) reflect warnings and dose limits but no ban. Dose safety (74) and interactions (70) are mid-range. The score sits just above ashwagandha, which has a similar liver signal but has been banned in Denmark.