General safety considerations

When taken orally, turmeric (Curcuma longa) is usually well tolerated but most studies have been short.

• In human studies, doses of up to 8000 mg a day of turmeric have been used for eight months without toxic effects. Curcumin doses of up to 8000 mg a day have been used for three months without toxic effects.
• Giving curcumin with piperine enhances the absorption of curcumin which may have safety implications.

Gastrointestinal

Use caution if taking turmeric and have a gastrointestinal condition.

Evidence

Of all the adverse reactions reported to the UK Medicines and Healthcare Products Regulatory Authority (MHRA) for curcuma, the most common (around 16%) were for gastrointestinal effects, including:

• diarrhoea
• constipation
• abdominal distension
• flatulence
• dyspepsia
• nausea

Other gastrointestinal effects seen commonly in clinical trials are:

• gastroesophageal reflux
• vomiting
• yellow stool
• stomach ache

Often, these common gastrointestinal effects are mild and occur at a similar rate with placebo and turmeric in clinical trials.

Liver

Avoid turmeric and curcumin in individuals with bile duct obstruction, cholangitis (bile duct inflammation), liver disease, gallstones, or any biliary disease.

Evidence

Turmeric extracts can trigger biliary colic (abdominal pain) in people with gallstones. About 7% of the adverse reactions reported to the MHRA for curcuma were for hepatobiliary disorders or abnormal liver function test results.

In people taking turmeric as a medicine, there have been reports of:

• hepatitis
• autoimmune hepatitis (case 1, case 2)
• drug-induced liver injury

In four published cases of hepatitis or liver injury, turmeric had been taken for three to ten months before the adverse effects were identified, and liver function returned to normal or was greatly improved within a month of discontinuing the turmeric.

Cardiovascular

Turmeric or curcumin-containing preparations may cause heart rate or rhythm disorders.

Evidence

Cardiovascular disorders, including rate and rhythm disorders of the heart, account for nearly 7% of the adverse effects that have been reported to the MHRA for curcuma.

A person experienced atrioventricular heart block a month after starting to take 1500 to 2250 mg of a multi-ingredient supplement containing turmeric. Their heart rhythm normalised three days after stopping the supplement, but the side effect returned when the supplement was restarted.

The supplement was discontinued and no further heart rhythm disturbances were noted in the six months that followed.

In this case, it was possible that an ingredient in the supplement other than turmeric caused the effect.

Blood

Curcumin may have antiplatelet (blood thinning) effects.

Advice for surgical procedures

If taking turmeric orally as a medicine, stop taking it at least two weeks before elective surgical procedures.

Skin

Pitting oedema and itching are uncommon with turmeric, but have been reported in people who took turmeric orally.

Allergic contact dermatitis, contact urticaria and itching have been reported when turmeric was used topically.

Other effects

Until more is known, use turmeric and curcumin with caution if you have a hormone-sensitive condition such as breast cancer or endometriosis.

Turmeric may have weak oestrogen-like actions.

Yellow card scheme

Reporting adverse reactions via the Yellow Card Scheme can lead to important warnings about the safety of medicines.

Use the Yellow Card Scheme to report any suspected adverse reactions to turmeric or curcumin.