Possible Drug Interactions With Chamomile

Chamomile tea, dried flower, tincture, and capsule

 Verywell / Anastasia Tretiak

Though natural, herbs can still pose medication interactions. There have actually been very few reported interactions between chamomile and over-the-counter or prescription drugs, but the most significant ones are related to use of the herb with Coumadin (warfarin)—a common blood thinner—and cyclosporine—a drug used to prevent rejection after organ transplantation. There are also theoretical interactions that could occur due to the biochemistry of chamomile.

Used by some for insomnia and settling the stomach, among other issues, chamomile is available in teas and in supplement form.

As with all herbal supplements, chamomile hasn't been tested for safety in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications. If you're considering the use of chamomile, talk with your doctor first.


Coumadin (warfarin) is derived from coumarin, a compound commonly found in plants such as chamomile that can have anticoagulant properties depending on its chemical structure. This drug is commonly prescribed as a blood thinner to prevent clots that may lead to a heart attack, stroke, or deep venous thrombosis (DVT).

Taking too much warfarin on its own can result in bleeding, but there is potential for the same thing to occur when the correct dosage is adhered to and high concentrations of a coumarin-containing herb or product—like chamomile—is consumed as well. While there is no evidence of a drug-herb interaction between warfarin and chamomile, there has been one documented clinical case of internal bleeding in a person consuming chamomile tea and using chamomile lotion in addition to warfarin.

With this concern, talk to your doctor before taking herbal supplements if you are taking other medications aimed at blood-thinning or preventing blood clots. These medications include aspirin and platelet inhibitors such as Ticlid (ticlopidine) and Plavix (clopidogrel).

There are many other herbs that carry warnings about interactions with anticoagulants, including Ginkgo biloba, garlic, and ginseng.

Health Benefits of Chamomile
Illustration by Emily Roberts, Verywell


Cyclosporine is used by transplant recipients to prevent rejection. It has a narrow therapeutic window, meaning that the amount taken needs to be precise in order to get the desired effects.

Cyclosporine is broken down in the liver by the CYP3A4 enzyme. Chamomile inhibits the function of this enzyme.

There has been a documented case in which the levels of cyclosporine were raised when a person taking the drug was drinking chamomile tea regularly. When they stopped the tea, their cyclosporine level dropped.

As a result of this and other reports, healthcare providers advise against consuming chamomile while taking anti-rejection drugs.

Theoretical Interactions

Chamomile has compounds that inhibit drug-metabolizing enzymes of the human cytochrome P450 family (CYP1A2, CYP2C9, CYP2D6, and CYP3A4). As a result, blood levels for various drugs may be higher than expected when chamomile is consumed.

There have not been documented reports of this occurring, other than for warfarin and cyclosporine. But it is theoretically possible to occur with use of the following drugs, which are metabolized by CYP1A2, in combination with chamomile:

Several studies have looked into using chamomile for blood glucose control in people with diabetes. Some have found effects in lowering insulin levels.

As such, it is best to discuss chamomile with your healthcare provider if you have diabetes and are taking insulin.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Center for Complementary and Integrative Health. Chamomile. Updated September 2016.

  2. Consultative Hemostasis and Thrombosis, 3rd ed. “Dietary Supplements and Hemostasis.”

  3. Ge B, Zhang Z, Zuo Z. Updates on the clinical evidenced herb-warfarin interactionsEvid Based Complement Alternat Med. 2014;2014:957362. doi:10.1155/2014/957362

  4. Agbabiaka TB, Wider B, Watson LK, Goodman C. Concurrent use of prescription drugs and herbal medicinal products in older adults: a systematic reviewDrugs Aging. 2017;34(12):891–905. doi:10.1007/s40266-017-0501-7

  5. Colombo D, Lunardon L, Bellia G. Cyclosporine and herbal supplement interactionsJ Toxicol. 2014;2014:145325. doi:10.1155/2014/145325

  6. Ganzera M, Schneider P, Stuppner H. Inhibitory effects of the essential oil of chamomile (Matricaria recutita L.) and its major constituents on human cytochrome P450 enzymes. Life Sci. 2006;78(8):856-61. doi:10.1016/j.lfs.2005.05.095

  7. Rafraf M, Zemestani M, Asghari-jafarabadi M. Effectiveness of chamomile tea on glycemic control and serum lipid profile in patients with type 2 diabetes. J Endocrinol Invest. 2015;38(2):163-70. doi:10.1007/s40618-014-0170-x

Additional Reading