Note: The U.S. Food and Drug Administration (FDA) does not approve supplements for safety or effectiveness. Talk to a healthcare professional about whether a supplement is the right fit for your individual health, and about any potential drug interactions or safety concerns.
Turmeric, a classic Indian spice and the main source of the natural compound curcumin, isn’t just a tasty addition to a meal — it also packs some serious health benefits, which is why high doses of the spice are often available in supplement form. But it’s possible to have too much of a good thing. In fact, too much turmeric may cause side effects, such as digestive issues.
That said, “supplementing turmeric has many potential benefits,” says Kristen Gradney, RDN, a dietitian and chief wellness officer for LCMC Health based in Baton Rouge, Louisiana. “[It’s] been associated with anti-inflammatory, anticancer, antidiabetic, antidiarrheal, antimicrobial, antiviral, and antioxidant properties.”
But moderation matters — here’s what to know to avoid overdoing it.
The FDA has recognized turmeric and turmeric extract as generally safe when added as a spice to foods.
In general, it’s safe to take up to 8 grams (g) — 3 teaspoons (tsp) — of turmeric (or curcumin) per day, says Gradney, citing research. Doses higher than that could cause digestive discomfort, she adds. And you should always speak with your healthcare provider if you have specific concerns before adding turmeric supplements to your diet.
There’s not one consistently recommended dosage for turmeric supplements. Clinical trials have found that taking up to 8,000 milligrams (mg) — or 8 g — per day of curcumin, the compound found in turmeric known for having many health benefits, is generally safe, according to one review. However, this may be too much for people with certain health conditions or who are taking certain medications, says Gradney. (More on that later.)
According to the aforementioned review, clinical trials have also found that doses up to 12,000 mg per day of 95 percent concentration of three curcuminoids: curcumin, bisdemethoxycurcumin, and demethoxycurcumin, are generally safe and tolerable.
However, the review also notes that some people who took doses of curcumin as high as 12,000 mg per day experienced side effects like digestive issues.
The Joint United Nations and World Health Organization Expert Committee on Food Additives (JECFA) and the European Safety Authority (EFSA) both recommend taking up to 3 mg of curcumin per kilogram of body weight a day.
There haven’t been many studies looking at the negative long-term side effects associated with taking a turmeric or curcumin supplement.
“Most of the current published information for long-term complications of turmeric supplementation are related to liver injury,” says Gradney. Beyond that, there’s some evidence of potential interactions, as well as a few small studies showing short-term side effects.
Turmeric May Lead to Liver Injury
Though rare, it’s possible that taking too much turmeric could damage your liver, says Gradney. A recent, small study linked turmeric to liver injury in 10 people. Some cases were severe — five people were hospitalized, and one died from liver failure.
The researchers noted that some of the damage may be associated with taking turmeric with black pepper, which increases the amount you absorb. The study also found a possible genetic connection: Most of the people studied had a specific gene variant that may make them more susceptible to turmeric-related liver damage.
While this research does establish a rise in liver-injury reports and that this gene variant may play a role, it falls short of explaining exactly why, says Ana Pruteanu, RDN, LDN, owner of Be Well Nutrition Counseling in Chicago.
“This study doesn’t describe doses of turmeric that were consumed to understand total intake that may have been linked to liver injury,” she says. “It confirms that individuals with [a certain genetic makeup] are more likely to experience liver injury, but it's not clear what percentage of the population has this genetic makeup.”
Turmeric May Limit Iron Absorption
If you have an iron deficiency, note that turmeric may further limit absorption of iron. One study found that an older man who took 538 mg of turmeric extract daily developed low iron levels and anemia, which improved after he stopped taking the supplement. While this is an isolated case, it aligns with research in animals, highlighting the need for more research on how turmeric affects iron levels.
That said, Pruteanu notes that this was an observational study of one person who had low iron levels even before taking a turmeric supplement, so the link between turmeric and low iron levels can’t be determined. “While his iron levels improved after discontinuing the turmeric supplementation, it is difficult to conclude that turmeric was the reason for low iron absorption,” she says. “More studies are needed to confirm this phenomenon.”
Turmeric May Interact With Blood Thinners and Other Medications
If you’re taking blood thinners like warfarin (Coumadin), clopidogrel (Plavix), or aspirin, turmeric can strengthen the effects of these medications, which may raise your risk of bleeding, says Gradney.
There’s little research to show how much curcumin can produce these effects, so if you take blood-thinning medication, it’s best to talk to your doctor before trying a turmeric supplement, she adds. If your medical provider does say it’s safe, be sure to stop taking your supplement at least two weeks before any surgery to avoid potential complications.
In addition to blood thinners, one comprehensive review advised approaching curcumin supplements with caution if you take antidepressants, antibiotics, antihistamines, heart medications, or chemotherapy treatments. Gradney agrees with these findings, and also echoes the researchers' point that more human studies are needed to fully understand how turmeric interacts with certain medications and the potential effects. Since the research isn’t yet conclusive, she recommends checking with your doctor before taking turmeric, especially if you’re on medication, pregnant, or breastfeeding.
Turmeric May Lower Blood Sugar Too Much
Research suggests that curcumin can help manage diabetes by reducing inflammation, oxidative stress, and blood sugar levels.
However, turmeric can lower your blood sugar and may also magnify the effects of certain diabetes medications, increasing your risk of low blood sugar (also known as hypoglycemia), says Gradney, so check with your doctor before taking any turmeric supplements for diabetes.
Turmeric May Cause Kidney Stones
Turmeric supplements may increase your risk for kidney stones, especially if they run in your family, says Gradney. Turmeric is high in oxalate, a chemical that your body releases through urine.
While there’s some older research to back this up, more and larger studies are needed to better understand the connection between turmeric and kidney stones.
Turmeric May Lead to Nausea, Diarrhea, and Headache
One review notes that some people experienced nausea, diarrhea, yellow stool, and headache after taking doses of curcumin from 500 to 12,000 mg per day.
While this review was based on older studies, Gradney notes that turmeric spice and related supplements can cause abdominal pain, nausea, and diarrhea when taken in high dosages.
Dana Angelo White, RD, the owner of Dana White Nutrition in Fairfield, Connecticut, recommends opting for whole food sources over supplements because they offer a broader spectrum of nutrients, not just a concentrated dose of one.
For example, you might add fresh or powdered turmeric to your meals. It’s especially common in South Asian and Middle Eastern cooking, including in soups, curries, rice dishes, and curry powders.
Still, it’s worth noting that the body doesn’t absorb turmeric well, and what it does absorb is rapidly metabolized and eliminated. Because turmeric is water-repellent, it’s harder for the walls of your intestines to soak it in (like a sponge). While White recommends getting nutrients from whole foods whenever possible, supplements may be a more effective way to get a concentrated, higher dose of turmeric, but it’s important to speak to your healthcare provider first, to determine if turmeric supplementation is right for you.
To boost absorption, you can pair your turmeric with black pepper or look for a supplement with piperine in it, per Johns Hopkins Medicine. Piperine is a compound in black pepper that’s been shown to help your body absorb turmeric. In fact, piperine can help your body absorb up to 20 times more turmeric.
If you're not at risk of turmeric toxicity (based on the side effects described above), you can add 1/20 tsp of pepper to increase the bioavailability. That means all you need is a shake of pepper and it will increase the absorption of turmeric.
Gradney also suggests taking your supplement with a meal that includes fat, which can help you better absorb the spice. She also says it’s worth considering a curcumin supplement instead of turmeric. “Curcumin is the active substance that gives turmeric its many benefits; however, the concentration of curcumin in turmeric is only between 2 and 6 percent,” says Gradney. “Dosages within [curcumin] supplements are much higher.”
Whether you opt for a turmeric or curcumin supplement, though, make sure you shop around to find one that’s been third-party tested for safety. Why? The FDA doesn’t require dietary supplement manufacturers to prove their products are safe or effective before they hit the market.
According to Gradney, NSF International, ConsumerLab, and USP are the top third-party testing companies to look for on any supplement label. “Good brands to choose are Garden of Life, Nature Made, Thorne, and Klena Athlete,” she adds.
Taking up to 8 g (3 tsp) of turmeric or curcumin per day is safe for most people, and turmeric is unlikely to cause side effects when it’s added to a dish as a spice.
Curcumin is the beneficial compound in turmeric, so taking a curcumin supplement could potentially have more health benefits than consuming turmeric or a turmeric supplement.
Talk to your doctor before taking turmeric or curcumin supplements, especially if you’re pregnant or breastfeeding, have diabetes or take antidepressants, antibiotics, antihistamines, anticoagulants, or heart medications.
