Turmeric found in food is considered safe. In supplemental form, turmeric and its active ingredient, curcumin, are also safe, as long as you take the recommended dose and are not pregnant. Serious dangers have not been reported, even in people taking large, therapeutic doses, but turmeric and curcumin have the potential to interact with medications and aggravate some medical conditions. Even though side effects are rare, consult your health care provider before taking supplements if you have any health concerns.
The rootstalk of the turmeric plant is commonly used in curry powder, where it contributes an intense yellow-orange color and pungent flavor. Turmeric’s rootstalk contains water-soluble compounds known as curcuminoids. The primary curcuminoid -- curcumin -- is the active ingredient responsible for most of turmeric’s benefits and potential side effects.
Curcumin has antioxidant and anti-inflammatory properties. It may help relieve symptoms caused by rheumatoid arthritis, according to a study in Phytotherapy Research in November 2012. A review in the May 2013 issue of Cancer Prevention Research reports that curcumin also shows promise for inhibiting cancer growth.
Interactions With Medications
Turmeric supplements may increase the risk of bleeding if you also take blood-thinning medications, including over-the-counter options such as aspirin and ibuprofen, reports MedlinePlus. These supplements may also lower blood sugar, so don't mix turmeric or curcumin with diabetic medications. If you're being treated for cancer, be aware that turmeric may interfere with some medications used to fight the disease, so you will need to ask your oncologist about taking it.
Supplements may affect the ability of your liver to metabolize and detoxify a variety of prescription medications. Turmeric can also block the action of drugs designed to lower stomach acid. As a safety measure, consult your physician before taking turmeric supplements if you use any type of medication.
Cautions for Health Conditions
Research to date hasn’t determined whether turmeric is safe to use during pregnancy, but MedlinePlus notes it may promote a menstrual period or stimulate the uterus, which would increase the risk of miscarriage. For this reason, pregnant women should stay away from turmeric supplements.
Don’t take turmeric if you have diabetes due to its potential to lower blood sugar. Also be careful about taking supplements if you have an iron deficiency because turmeric may block iron absorption.
Avoid taking turmeric supplements if you have liver disease, kidney disease, gastroesophageal reflux disease or gallbladder problems because it may aggravate these conditions. Talk to your doctor before taking turmeric if you have an estrogen-sensitive health condition, such as endometriosis, uterine fibroids or breast cancer.
Other Safety Issues
The active ingredient in turmeric, curcumin, has the potential both to help or to harm the liver. Research using laboratory animals suggests it might help prevent liver disease, according to studies cited by NYU Langone Medical Center. A more recent study using lab mice found that it accelerated liver damage, but its impact depended on the dose, according to a study in Phytotherapy Research in December 2012.
In very rare cases, turmeric has been reported to cause an allergic reaction or a skin rash if used topically. Taking very large amounts for a long time may cause stomach upset and ulcers, according to the University of Maryland Medical Center.