Turmeric is a spice containing curcumin, which may have antioxidant, anticancer, and anti-inflammatory potential. Experts warn that it can interact with certain medications, especially when taken in large quantities.

1. Aspirin

Aspirin reduces the clumping of platelets, which decreases the formation of blood clots responsible for heart attacks and strokes, said Maria Pino, Ph.D., an associate professor at New York Institute of Technology College of Osteopathic Medicine and a licensed pharmacist.

In some preclinical studies, turmeric has been observed to display similar effects to aspirin as an anti-inflammatory and antiplatelet drug. Combining them can therefore lead to an increased chance of bleeding externally and internally, Pino explained, which can be dangerous.

Other antiplatelet drugs, such as clopidogrel, and anticoagulants, such as warfarin and rivaroxaban, which are often used to reduce the risk of stroke from atrial fibrillation, have also shown a similar enhanced bleeding risk when combined with turmeric.

2. Insulin and Glipizide

These medications are used to reduce blood sugar in people with diabetes. Research has meanwhile shown that turmeric can increase the regulation of proteins involved in insulin release, potentially leading to a drop in blood sugar levels.

“Turmeric can potentially help lower blood sugar, which could lead to hypoglycemia if combined with prescription diabetes medications,” said Marissa Mauricio, PharmD, a clinical pharmacy specialist at Baptist Health South Florida.

This can cause symptoms such as blurred vision, dizziness, sweating, heart palpitations, and confusion. In more severe cases, Mauricio said. hypoglycemia can cause loss of consciousness, seizures, or coma.

3. Amlodipine

Amlodipine is used to treat high blood pressure by blocking the entry of calcium into the blood vessels, which dilates them and reduces blood pressure.

One animal study found that amlodipine absorption increased when combined with turmeric.

“Higher levels of amlodipine in the body could result in decreased blood pressure and a greater risk of dizziness, with the possibility of falls being a concern for elderly patients,” Pino said.

4. Tacrolimus

Tacrolimus is an immunosuppressant medication that is used to prevent organ rejection after an organ transplant. However, it can also reduce kidney function.

In one case report, a patient experienced worsening kidney function following a recent high-dose intake of turmeric with his meals. Data from animal studies also found a change in drug metabolism with turmeric.

“This is likely attributed to turmeric preventing the breakdown of tacrolimus in the liver, leading to higher immunosuppressant levels,” Pino said.

5. Chemotherapy Drugs

Chemotherapy drugs kill cancer cells in a variety of ways. A study using human breast cancer cells as an experimental model found that turmeric could lessen the effectiveness of these chemotherapeutic agents.

However, Pino said additional studies are required to confirm whether dietary and supplemented turmeric should be avoided during cancer treatment, as turmeric also has potential anti-cancer effects.

6. Tamoxifen

Tamoxifen is an estrogen modulator that is used to manage breast cancer.

In one study, tamoxifen combined with turmeric was found to increase the liver metabolism of the breast cancer drug, lowering the drug’s effectiveness. But Pino said further studies are needed to include a greater patient population and to understand if this effect is patient-specific.

7. Losartan

This medication lowers blood pressure by dilating blood vessels and blocking a hormone that increases sodium and water retention.

Research has shown that turmeric can reduce the liver’s ability to break down the drug, leading to higher drug levels in the body. This can increase the risk of dizziness, cause a change in heart rate, and lead to muscle cramps.

8. Levothyroxine

Levothyroxine is a hormone replacement for patients with underactive thyroid function, also called hypothyroidism.

“For the highest absorption potential, levothyroxine should be taken on an empty stomach, before your morning meal, and several hours apart from other medications or supplements, including turmeric,” Pino said.

9. Antacids

These drugs neutralize stomach acid and help to manage indigestion and ulcers.

While turmeric does have anti-inflammatory potential in the gastrointestinal tract, curcumin can also stimulate stomach acid production.

“This effect could potentially reduce the effectiveness of antacid medications and worsen conditions like acid reflux,” Mauricio said.

10. Methotrexate

This medication interferes with the production of folate, which is needed for cell survival. It is used to treat rheumatoid arthritis, psoriasis, and cancer.

Because it is metabolized in the liver, other drugs or supplements (including turmeric), which reduce methotrexate’s breakdown, can potentially increase its adverse effects, including a greater risk for infections, Pino said.

Other Things to Consider

It’s important to note that cooking with turmeric in regular doses is generally considered safe from drug interactions. Supplements also pose a greater risk of drug interactions because they’re not regulated by the FDA.

“The form and dose of turmeric can make a big difference on the impact,” Mauricio said.

“High-dose turmeric supplements, especially those that include black pepper extract to boost absorption, are more likely to cause interactions with medications because the body absorbs it at a higher level,” she added.