Curcumin Side Effects & Interactions [Full Guide]

Curcumin and turmeric are a commonly used supplement and food additive.

But are they safe?

Click the following sections below or scroll down.

curcumin side effects
Scroll down to read the side effects of curcumin & turmeric.

What Is Curcumin & Turmeric

Turmeric is a type of flowering plant of the ginger family, Zingiberaceae.

Turmeric is usually consumed as a root, or in its powder form.

Curcumin is a compound found naturally in turmeric.

Curcumin belongs to a group of compounds known as curcuminoids.

It is the major curcuminoid found in turmeric.

It is also a food colouring and a flavouring.

Turmeric is consumed the most in India, followed by other countries such as Pakistan, China, Indonesia and Bangladesh.

India is also the largest producer and exporter of turmeric worldwide.

turmeric and curcumin
Turmeric is a type of flowering plant of the ginger family (Zingiberaceae).

What Are Curcumins Benefits

Curcumin is a potent antioxidant and a powerful anti-inflammatory.

It is on-par with some of the commonly used anti-inflammatory drugs.

It can reduce the risk of various diseases and chronic illnesses, such as cancer, heart disease, Alzheimer's disease and more.

Top Benefits Of Curcumin:

  • Reduces Inflammation: Chronic inflammation may be a significant aspect of many chronic diseases. Curcumin can suppress many of these molecules known to play significant roles in inflammation and, therefore, be beneficial in these chronic diseases.

  • Potent Antioxidant: Curcumin is a potent antioxidant. It has two main effects against free radicals; it directly blocks them and stimulates the body's free radical defences.

  • Lowers Risk Of Disease: Curcumin has many effects on the body, such as reducing inflammation, suppressing free radicals and improving various other systems, lowering the risk of multiple diseases such as cancer, heart disease, Alzheimer's, diabetes, arthritis and many more.


To summarise, curcumin has two main benefits; being a powerful antioxidant and anti-inflammatory, resulting in many benefits.

Further Reading: Top 10 Benefits Of Curcumin [Ultimate Guide]

curcumin benefits
Curcumin is a powerful antioxidant and anti-inflammatory.

Curcumin & Turmeric Side Effects

Curcumin appears to be generally safe to consume.

However, those taking other medications or those with biliary or gastrointestinal conditions should take curcumin or turmeric with caution, or avoid taking it at all.


Curcumin is considered safe, with minimal or no side effects at low dosages and short-term usage.

A study in 10 people found that taking ~490mg of curcumin daily for a week caused no notable side effects. (Source)

Additional studies noted that taking curcumin at dosages of 1,200-2,100mg per day for 2-6 weeks caused no notable side-effects. (Source, Source)

However, a small portion of people may experience some mild side effects, such as listed below.

Curcumin Side Effects:

  • Digestive: Some people may experience mild digestive side-effects such as stomach aches, acid reflux, bloating, constipation, distention, diarrhoea, yellow stool and flatulence at dosages exceeding ~1,000mg per day. (Source, Source)

  • Skin Rash: Some people have recorded a skin rash after taking ~8,000mg of curcumin or more, but this appears to be quite a rare occurrence. (Source)

  • Headache & Nausea: Curcumin dosages of ~450mg or higher may cause headaches, nausea and vomiting in some people. (Source, Source)

Very high curcumin dosages at 1,170mg per pound of body weight (2,600mg/kg) per day over a long time (years) may cause some severe side-effects, as seen in rats. (Source)

Severe Side Effects Of Extreme Dosages (seen in rats):

  • Increased Liver Size

  • Stained Fur

  • Stomach Ulcers

  • Inflammation

  • Increased Risk Of Intestinal/Liver Cancer

The dose is what makes this dangerous.

There is currently no evidence that more moderate curcumin dosages can cause severe side-effects in humans, especially when taken for a short time.

However, human studies on the long-term effects and side-effects of curcumin are lacking.

Curcumin Summary:

In some people, high dosages of curcumin can cause mild side-effects, but curcumin is generally considered safe. The long-term effects and side-effects of taking curcumin are unknown. In rat studies, extreme dosages produced some severe side-effects.

curcumin side effects
Curcumin is generally safe but does have some mild side effects.


Turmeric is around 2% oxalate.

When consumed in high doses, oxalate can contribute to the formation of kidney stones. (Source)

Also, not all turmeric and curcumin on the market is pure; this is why it is crucial to buy high-quality products.

The low-quality sources of turmeric and curcumin may contain toxic and potentially harmful byproducts of extraction.

Some studies have also shown that some turmeric powder on the market may contain fillers such as listed below. (Source)

Turmeric Fillers:

  • Cassava Starch

  • Barley

  • Rye Flour

  • Wheat

In some people with gluten allergies or celiac disease, it may cause a reaction.

Some turmeric powders on the market may also contain various food colourants, meant to improve colour.

A food colouring used frequently in India is metanil yellow.

Metanil yellow, in animal studies, can cause cancer and neurological damage. (Source, Source, Source)

The effects of metanil yellow on humans are unknown; however, it's illegal to use in Europe and the United States.

There may also be lead in some turmeric powders, a heavy metal that is incredibly toxic to the nervous system. (Source, Source)

Turmeric Side Effects:

  • Kidney Stones: Turmeric contains oxalate, a compound that can contribute to the formation of kidney stones at high doses.

  • Contamination: In some low-quality turmeric products, metanil yellow and other colourants, fillers and contaminants can be present.

  • Allergens: Some low-quality turmeric products may contain allergens such as cassava starch, barley, rye flour or wheat.

Turmeric Summary:

Turmeric, which is pure and free of contaminants, is considered safe. However, turmeric from low-quality sources may also contain toxic and potentially dangerous fillers, food colourings, additives, and heavy metals.

turmeric side effects
Turmeric, which is pure and free of contaminants, is considered safe.

Curcumin & Turmeric Dosage

Turmeric has no official dosage recommendations, and the upper limit is not known.

The recommended dosage listed on most supplement labels is generally a useful reference.

Curcumin does have an official recommended dosages, though.

1.4mg of curcumin per pound (3mg/kg) of body weight per day is the acceptable dietary intake as set out by the Joint Expert Committee on Food Additives (JECFA).

For a 150lb (68kg) person, this would be around ~210 mg of curcumin each day.

One study concluded that 3,600-8,000mg dosages per day do not cause any severe side effects.

Another study showed that dosages of 12,000mg are well tolerated. (Source, Source)


Turmeric has no official recommended dosage, but curcumin does have an official recommended dosage, which is 1.4mg per pound (3mg/kg) of body weight.

turmeric and curcumin dosage
Turmeric has no official dosage, curcumins official dosage is 1.4mg per 1lb (3mg/kg) of body weight.


Curcumin and turmeric interact with various medications and diseases.

Curcumin Interactions:

  • Bile Duct Obstruction

  • Liver, Kidney, Biliary & Digestive Diseases

  • Cancer & Immunosuppressant Medications

  • Anticoagulant & Antiplatelet Medications

  • Blood Thinners & Blood Pressure Drugs

  • Diabetes & Statin Drugs

  • NSAIDs & Other Anti-Inflammatory Drugs

Those with bile duct obstruction, liver, kidney, biliary and digestive system disease and other similar conditions should avoid turmeric and curcumin due to its ability to increase bile secretion.

Curcumin and turmeric may also interact with some medications due to its effects on cytochrome P450 enzymes, OATP and P-glycoprotein transporters. (Source)

Those taking medication with significant side effects, such as cancer or immunosuppressant medicines, should take curcumin and turmeric with caution, or not take at all.

Curcumin has interactions with medications that reduce blood clotting (Anticoagulant/Antiplatelet drugs).

Turmeric and curcumin might reduce blood clotting even further.

Taking turmeric or curcumin with other medications that also reduce clotting might increase bruising and bleeding chances.

Other interactions exist, such as stomach acid drugs, diabetes and blood pressure medications, statins and other anti-inflammatory drugs.

turmeric and curcumin interactions
Curcumin has interactions with various diseases and medications.

Side-Effects Summary

Curcumin and turmeric are generally considered safe for consumption.

Usually, only mild side effects are associated with their usage at high dosages, mostly digestive issues.

However, some low-quality sourced turmeric and curcumin sometimes contain various contaminants.

Contaminants found in low-quality turmeric:

  • Heavy Metals

  • Allergens

  • Food Colourings

  • Additives

  • Metanil Yellow (a toxic food colouring widely used in India)

Turmeric and curcumin have some moderate interactions with certain medications and can affect some diseases.

Overall, curcumin and turmeric are safe for consumption when from a high-quality source and avoided with medication interactions.

turmeric and curcumin side effects
Curcumin & turmeric are safe for consumption from a high-quality source.

Frequently Asked Questions

Q: Does curcumin affect the liver?

A: Curcumin can alter the levels of enzymes within the liver. Those with liver diseases and conditions should avoid taking curcumin and turmeric.

Q: Is turmeric bad for your kidneys?

A: In healthy people, turmeric and curcumin should not affect the kidneys. Those with kidney issues should strictly avoid turmeric.

Q: What medications should not be taken with curcumin?

A: Take curcumin with extreme caution, or not all, in those taking stomach acid drugs, diabetes and blood pressure medications, statins and other anti-inflammatories, cancer and immunosuppressant drugs.

Q: Is it safe to take curcumin daily?

A: Long-term safety studies are lacking. However, studies suggest curcumin is safe for short-term usage.

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