7 mins read

Overview: Kava is a plant called Piper methysticum. It’s also known as kava kava or ava pepper. Kava root is used to make dietary supplements, such as tablets or capsules. It is also used to make a beverage called kava. People take kava for many reasons, although its benefits are not well defined. Common side effects include dizziness, headache, and stomach upset. Serious side effects are rare and include liver damage. Before taking kava, make sure to tell your health care provider about any health conditions you have or medicines you are taking.

Uses

What is kava used for?

Kava is used as a beverage and as a dietary supplement for various reasons. But the benefits of kava are not well defined. Some common reasons that people use kava include the following.

Note: The FDA has not reviewed kava for safety and effectiveness. Learn more about dietary supplements here.

How does kava work (mechanism of action)?

Dietary supplements and beverages containing kava are made from the root (rhizome) of the plant.

Certain chemicals found in kava, called kavalactones, can have effects in the body. These effects include relaxing the muscles, causing drowsiness, and reducing pain sensations. Kavalactones may also change the levels of certain chemicals in the brain. But it is unclear how well kavalactones work for improving sleep or for reducing anxiety, symptoms of menopause, or stress.

Herbal products such as kava naturally contain many different chemicals, such as kavalactones. The amounts of each chemical in a specific kava product may vary from product to product. Different amounts of kavalactones may change the effects of kava on the body. Some kava dietary supplements are made to contain a specific amount of kavalactones. But the amount of kavalactones in kava beverages is usually unknown.

How should I store kava?

You should store kava according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.

Side Effects

What are the most common side effects of kava?

The most common side effects of kava are listed below. These side effects may vary depending on the dose you are taking or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.

  • Dizziness
  • Headache
  • Stomach upset

There may be other side effects of kava that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of kava?

While less common, the most serious side effects of kava are described below, along with what to do if they happen.

Severe Allergic Reactions. Kava may cause allergic reactions, which can be serious. Stop taking kava and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching or skin rash
  • Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking kava. This risk may be higher in people who regularly take high doses of kava or who use medicines that can harm the liver. Call your health care provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Skin Reaction (Kava Dermopathy). Some people who regularly use large amounts of kava have had a skin condition called kava dermopathy. This skin condition causes rough, dry, and scaly patches to form on the body. These patches usually start on the head, face, and neck and then spread to other parts of the body. Some people may also have hair loss, swelling of the face, or tingling and numbness in the hands or feet. Stop taking kava and contact your health care provider right away if you get any of these symptoms.

Warnings & Precautions

Who should not use kava?

Allergies to Ingredients. People who are allergic to any of the following should not take kava.

  • Ava pepper
  • Kava
  • Piper methysticum
  • Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific kava products they stock.

What should I know about kava before using it?

Kava is available as a dietary supplement, usually as a capsule or tablet that contains the root of the plant. It is also available as a beverage, which is usually made by soaking kava root in either water or coconut milk. Kava cannot be marketed to treat or cure a disease.

Read and follow the directions on the specific product you are taking, or take it as recommended by your health care provider.

Keep kava out of the reach of children.

Kava can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how kava affects you.

Drinking kava as a beverage can cause numbness or tingling of the mouth. This sensation lasts for only a short time as the beverage passes through the mouth and into the stomach.

Herbal products, such as kava, naturally contain many different chemicals. The amount of each chemical in a specific kava product can change for many reasons, including the area where the plant was grown, the weather during growth, the time of year when it was harvested, and the way that the plant was processed after it was harvested. If you switch to a new bottle or a different brand, you may not have the same effects or side effects because of this variability. Talk to your health care provider if you have questions or concerns.

The FDA has not tested kava products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.

What should I tell my health care provider before using kava?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if kava is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

Other Medicines and Supplements. Kava may interact with other medicines and supplements. Before taking kava, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how kava could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if kava passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does kava interact with foods or drinks?

There are no known interactions between kava and foods or drinks.

It is unknown if drinking alcohol will affect kava. But the risk of certain side effects, such as drowsiness or liver damage, may be increased if you drink alcohol while taking kava.

Does kava interact with medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking kava.

  • Acetaminophen (Tylenol), which is a medicine used for pain or fever
  • Any medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, or medicines for anxiety
  • A barbiturate, such as butalbital, phenobarbital, or primidone, which is a medicine that may be used to treat insomnia, migraines, or seizures
  • A benzodiazepine, such as clonazepam (Klonopin), diazepam (Valium and others), or lorazepam (Ativan and others), which is a medicine used for anxiety, muscle spasms, or seizures
  • A muscle relaxant, such as carisoprodol (Soma), cyclobenzaprine, metaxalone, or tizanidine (Zanaflex)
  • An opioid, such as codeine, fentanyl, morphine, oxycodone, or tramadol, which is a medicine used for certain types of pain

The interactions between kava and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with kava is incomplete. Always check with your health care provider before taking kava with any medicines.

Overdose/Missed Dose

What should I do if I accidentally use too much kava?

If you or someone else has used too much kava, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

Kava is available as a dietary supplement and as a beverage. There is no typical dose of kava when it is consumed as a beverage. When taken as a dietary supplement, the dose of kava is usually based on the amount of kavalactones, which can vary from product to product.

Read the product label closely and speak with your health care provider about how to use kava safely. Since kava can affect your awareness and coordination and also make you drowsy, you should not drive until you know how kava affects you. Do not take double or extra doses, even if you miss a dose.