People have used plants to treat illness and support health for thousands of years. It’s likely that 80% of people around the world today use some kind of herbal medicine or supplement. But it can be hard to know what really works or what’s safe to take. This is especially true when you have certain health conditions or if you take other medications.
Here, we’ll take a closer look at kava, a natural remedy from the Pacific Islands that people around the world use for stress and anxiety relief.
Where does kava come from?
Kava, also called kava kava, is made from the root of a plant called Piper methysticum. The plant is a member of the pepper family and grows on islands in the Pacific Ocean. Kava has been used for centuries by Indigenous people there. They take it to relieve pain, for relaxation, and as a part of sacred rituals. In local languages, the word “kava” refers to its bitter taste.
What does kava do to the body and brain?
The active substances in kava are called kavapyrones. We don’t fully understand the way they work yet. But they do seem to affect the way that nerves send messages in the body.
For example, we know that kava affects GABA (gamma-aminobutyric acid) nerve receptors. Alcohol and certain medications for anxiety and pain also work on these receptors. For some people, using kava results in a feeling of calm or pain relief.
Is kava like alcohol?
Some of kava’s effects are like those of alcohol, while others are not. In one study, kava didn’t impair thinking or reaction time as much as alcohol. But people were more impaired when they used kava together with alcohol than they were with alcohol alone.
In one review of kava research studies, people had slightly slower reaction times when they drank kava by itself. But once again, they were more impaired when they combined kava with alcohol.
By itself, kava seems to produce relaxing effects similar to those of alcohol but with less mental clouding. Because of kava’s effect on muscles, you may experience some similar physical effects, like slower reaction times, slurred speech, and an unsteady gait.
And while kava affects some of the same receptors as alcohol, it doesn’t appear to be addictive in the same way that alcohol can be. But more research is needed on the risks of impairment and addiction with kava.
How do you take kava?
What form does kava come in?
The traditional way to use kava is as a beverage made from the roots of the plant. Many people now take kava in other forms like powders, extracts, or capsules. In some places, kava bars and cafes have become popular.
What is kava used for?
The most common reason that people use kava is to help with stress and anxiety. This is also the reason that has been studied the most.
Kava research has been mixed in terms of benefits and safety. But as a natural remedy for anxiety, there is more evidence for the benefits of kava than there is for most other herbs and supplements.
Short-term benefits
When it comes to managing stress and anxiety, kava seems to have some short-term benefits. It may be especially helpful when there’s a situation that’s causing stress. There’s less evidence that it helps for long-term or generalized anxiety. It may also help with symptoms of anxiety during perimenopause. And it’s probably safe for most people in limited amounts, especially for short-term use.
Other uses
Researchers are studying other uses of kava too. Some research shows that kava may help prevent and treat certain kinds of cancer. And like some other plant-based foods, kava may also have anti-inflammatory properties. But these are still new areas of research without conclusive answers.
What are the side effects of taking kava?
People often take kava to feel relaxed. But there can be side effects, such as:
- Headache
- Dizziness
- Feeling too drowsy
- Feeling down or depressed
- Diarrhea
- Numbness in the mouth, throat, or tongue
What happens if you take too much kava?
Everyone experiences the effects of medications, foods, and supplements in different ways. The right amount for one person may be different for someone else. But most experts agree that, in general, taking up to 400 mg of kava a day is probably safe for most people.
If you take too much kava all at once, you may experience:
- Weak or uncoordinated muscles
- Nausea
- A slight fever
- Dilated (large) pupils
- Red eyes
- Feeling very sleepy
People who use a lot of kava over longer periods of time may have:
- Mood swings
- Weight loss
- Dry and scaly skin
- Shortness of breath
- A loss of interest in relationships and activities
- More frequent infections
What should you do if you’ve taken too much kava?
It’s unusual to have serious side effects from taking kava by itself. But it can be dangerous to take kava with alcohol, sedatives, or other medications that cause drowsiness or affect the liver. The potential side effects can include liver damage and coma.
If you are worried that you or someone else is having an abnormal reaction to kava, seek emergency medical care. This means calling 911 or going to your local emergency room. You also have the option to call Poison Control at 1-800-222-1222, but this is a better option if you are not having serious symptoms.
If you take a lot of kava over time and notice side effects, call a healthcare provider right away. This is especially important if you have abdominal pain, swelling, or a change in skin color. These could be signs of liver damage.
Who should not take kava?
Most people can probably take kava safely in limited amounts. But it could be riskier for others. Avoid kava if you:
- Have liver disease
- Will be driving or operating heavy machinery
- Are also drinking alcohol or taking medications that cause sedation
- Are pregnant, breastfeeding, or a child
- Will be having surgery or a procedure with anesthesia
Talk with a healthcare provider about your health conditions and medications. Taking kava with some medications can cause side effects or affect how well they work.
Does kava damage the liver?
Kava has been restricted or banned in some countries because of the potential for liver damage. In recent studies, this risk appears to be small but real. Liver damage from kava may be mild or severe. It’s usually reversible if you stop taking kava.
In the U.S., the FDA issued a consumer advisory in 2002 based on cases of liver damage from kava. Studies since that time suggest that the risk of liver damage is higher with:
- Doses that are too high
- Poor-quality kava
- Taking kava with alcohol or other medications that affect the liver
- Taking kava for long periods of time
Is kava FDA approved?
The FDA does not approve supplements. Manufacturers are responsible for making sure their products are safe. The FDA will remove a product from the market if it’s found to be unsafe or if the claims about how well it works are false.
Although the FDA made its warning about possible liver damage in 2002, it did not ban or remove kava from the market. Studies since then have continued to add to what we know about kava’s effects and safety.
The bottom line
Kava has been used as an herbal supplement and traditional remedy for a long time. It may help some people relax or deal with stress. It might even have other health benefits. But just like any medicine, supplement, or treatment, it’s not right for everyone. It’s best to talk with a healthcare provider about kava, especially if you take other medications or have certain health conditions.