Consuming turmeric supplements in high amounts may cause symptoms, including an upset stomach. It may also not be safe to take alongside certain medications.
Turmeric is a yellow-orange spice originating in southern Asia. It is a popular ingredient in many Indian and Middle Eastern dishes.
It is often consumed for its health benefits. Supplements containing turmeric or curcumin — its main active ingredient — are becoming increasingly common.
However, some people are concerned about the possible side effects of high dose turmeric and curcumin supplements. Learn more about what the evidence says.
What is turmeric?
Turmeric, also known by the scientific name Curcuma longa, is an ancient Indian spice, medicinal herb, and food dye in the ginger family.
Turmeric has many health benefits and may help with several conditions, such as arthritis, digestive disorders, respiratory infections, allergies, and depression.
The root stalks are rich in plant compounds called curcuminoids. These curcuminoids are the main active compounds in turmeric. They are responsible for turmeric’s orange-yellow color and most of its health benefits.
While turmeric can be consumed raw or in powder form, it is also widely available in the form of dietary supplements.
Some cheap turmeric powders may also contain additives that are not listed on the labels. This is called turmeric adulteration, and it is discussed in more detail below.
Adverse effects of turmeric
Turmeric is generally considered safe and without any serious side effects. However, some people may experience side effects when they take them in large doses as supplements.
This includes:
- Not all commercial turmeric powders are pure: This means that cheaper and potentially toxic ingredients have been added and are not listed on the label.
- May contain fillers: Studies have revealed that commercial turmeric powders may contain fillers such as cassava starch or barley and wheat or rye flour. This can cause adverse symptoms in people with gluten intolerance or celiac disease.
- May contain questionable food colorants: Some turmeric powders may also contain questionable food colorants, which are added to improve color when the powder is diluted with flour.
- May be high in lead: Some turmeric powders may be high in lead, a heavy metal that is especially toxic to the nervous system.
Drug interactions
Dietary turmeric does not significantly influence how your body processes medications. However, turmeric’s supplemental effects may increase or interfere with the actions of some of the medications you are taking.
This includes:
- Anticoagulation effect: This means it can interfere with blood clotting. Taking curcumin with anticoagulant drugs or blood thinners such as aspirin, clopidogrel (Plavix), or warfarin (Jantoven) can increase their effects and may lead to excessive bleeding.
- Lower blood sugar levels: Turmeric can also lower blood sugar and may enhance the effects of antidiabetic drugs or insulin.
If you’re considering taking a new supplement, always talk with a doctor first. They can identify any possible interactions with medications you’re already taking.
Adverse effects of curcumin
Curcumin supplements are considered safe, and no adverse side effects have been reported at low doses.
A 2021 review also found that taking doses of around 1,000 mg of curcumin per day did not lead to any apparent adverse effects.
Yet, a small proportion of people may experience some mild side effects at higher doses. These may include:
- Digestive issues: People may experience mild digestive issues such diarrhea
- Headache: Doses of 500 mg or higher may cause headache and nausea in a small number of people.
- Skin rash: Some people have reported a skin rash after taking curcumin, but this seems to be very rare.
However, there is currently no evidence that lower amounts of curcumin cause serious side effects in humans when taken over short periods, though human studies on the long-term effects are lacking.
Drug interactions
While curcumin has a very good safety profile, some research suggests it may affect how your body processes certain medications, including:
- antibiotics
- anticoagulants
- antidepressants
- antihistamines
- cardiovascular drugs
- chemotherapeutic agents
That said, research on possible drug interactions with curcumin is limited and doesn’t provide enough evidence to say with certainty whether taking curcumin supplements interacts with other medications you may be taking.
If you are taking other medications, talk with a healthcare professional before taking curcumin supplements.
How much is too much?
There are no official recommendations for the intake of turmeric, and the maximum tolerable intake level has not been identified.
However, as a general rule, you should not exceed the dosage recommendations you find on supplement labels.
On the other hand, there are some official guidelines for the intake of curcumin.
The Joint FAO/WHO Expert Committee on Food Additives (JECFA) set the acceptable dietary intake as 1.4 mg per pound (3 mg/kg) of body weight per day.
For example, for a 178-pound (81-kg) person, this would translate into 249 mg per day.
As always, talk with a doctor before deciding how much of a supplement you should start taking a day.
What are the benefits of turmeric?
Turmeric is used as a spice and food dye, adding both flavor and color to food. It has also been consumed for its health benefits. Almost all of these have been attributed to curcumin, its main active ingredient.
Curcumin supplements offer the following benefits, to name a few:
- Reduced inflammation: Chronic inflammation is associated with many diseases. Studies show that curcumin supplements may reduce levels of inflammatory markers and help treat or reduce symptoms of inflammatory health conditions, like inflammatory bowel disease, arthritis, psoriasis, depression, and atherosclerosis.
- Improved antioxidant status: Curcumin and other curcuminoids are powerful antioxidants that may improve your antioxidant status. Antioxidants protect against cellular damage from free radicals that are associated with health conditions like diabetes, heart disease, and cancer.
- Improved blood vessel function: Studies suggest that curcumin supplements may promote the dilation (widening) of blood vessels, increasing blood flow and reducing blood pressure.
- Reduced heart attack risk: They may also lower the risk of heart attacks, possibly through their anti-inflammatory effects by improving cholesterol levels.
- Support neurological health: Curcumin supplements may improve symptoms of neurodegenerative diseases, like Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and dementia.
How to ensure turmeric quality
Some turmeric powders contain cheap fillers not mentioned on the labels.
These adulterated powders are difficult to identify without a chemical analysis. Your best bet is to choose turmeric that has been certified by a reputable agency.
For instance, you could look for turmeric that has been certified organic by the U.S. Department of Agriculture (USDA).
If you are taking turmeric or curcumin supplements, select supplements that have a quality certification by a third party. Several companies provide quality certifications for supplement manufacturers.
These include:
- NSF International
- Informed Choice
- US Pharmacopeial Convention (USP)
Look for their seal on the packaging of products, or go to their websites to see what supplements they’ve certified.
Frequently Asked Questions
Who should not use turmeric?
Turmeric supplements should be avoided by people with liver or bile duct problems, as they can increase bile production. They should also be avoided if you are taking anticoagulants (blood thinners).
What drugs cannot be taken with turmeric?
Certain drugs cannot be taken with turmeric, such as anticoagulants (blood thinners), antacids, and diabetes medications.
Does turmeric help with sleep?
Animal studies show that turmeric may help with sleep as it increases the non-rapid eye movement phase of the sleep cycle, which can lead to better-quality sleep.
The bottom line
Turmeric and curcumin supplements do not seem to have any serious side effects.
However, some people may be prone to mild discomfort, such as headaches or diarrhea, at high doses.
Keep in mind that low quality turmeric may be adulterated with cheap fillers, such as wheat starch, which will cause adverse symptoms in people with gluten intolerance.
Curcumin supplements may also interact with other medications you are taking. It is important to speak with a doctor before taking curcumin supplements, especially if you are currently taking other medications, like blood thinners or insulin.
Just one thing
Try this today: Turmeric root is much sweeter than turmeric powder. If you’re looking to eat more turmeric but aren’t a big fan of supplements, buy the root from your local grocery store (it looks a lot like ginger), peel it, and use a small slice in the next smoothie you whip up! It will add a nice spicy zing.