Overview

Gamma-aminobutyric acid (GABA) is a type of brain chemical known as a neurotransmitter. Your body makes GABA on its own. It is also found in some foods and as a dietary supplement. There is interest in taking GABA for a wide range of purposes, but its benefits for any use are not well defined. Common side effects include skin tingling (with higher doses) and a small drop in blood pressure. Before taking GABA, make sure to tell your health care provider about any health conditions you have or medicines you are taking.

Uses

What is GABA (gamma-aminobutyric acid) used for?

Gamma-aminobutyric acid (GABA) is used for various reasons, but its benefits are not well defined. Some common reasons for using GABA include the following.

• Anxiety
• High blood pressure (hypertension)
• Trouble sleeping (insomnia)
• To help manage stress or improve mood
• To improve physical performance

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

How does GABA work (mechanism of action)?

GABA is an important brain chemical known as a neurotransmitter that is made by your body. Certain plant-based foods, including tomatoes, soybeans, and spinach, naturally contain a small amount of GABA. Other foods, including some teas, fermented foods, and sprouted beans or grains, contain large amounts of GABA. GABA is also available in dietary supplements, which are usually made from fermented beans.

Your brain and nervous system contain GABA receptors. The GABA in your body binds to these receptors and helps regulate signals and messages. GABA is considered an “inhibitory” neurotransmitter, which means that it works by slowing down the signals being sent by your brain and nerves. As a result, GABA receptors are an important target for problems such as anxiety and trouble sleeping (insomnia). In fact, there are many prescription medicines that act on GABA receptors, which are used to treat these conditions.

There are some claims that GABA supplements can be used as natural alternatives to prescription medicines that act on GABA receptors. But when GABA is taken by mouth, most of it does not cross into the brain. This means that GABA from supplements may not be able to bind to GABA receptors in the brain. In fact, most research shows that GABA does not help reduce anxiety or improve sleep any better than a placebo (a pill with no medicine). Although GABA supplements are also sometimes used to help manage stress or improve mood, their benefits for these uses are poorly studied and not well defined.

GABA has also been used to help lower blood pressure in people with high blood pressure (hypertension). Research shows that taking GABA supplements, usually about 80 mg daily, can lower blood pressure by a small amount. But this effect was not enough to bring blood pressure back to normal. If you have high blood pressure, speak with your health care provider about your options. You may need to use multiple treatments or lifestyle changes to reach your target blood pressure.

There is also interest in taking GABA supplements to help improve physical performance during exercise. But research is limited, and its benefits for this use are not well defined.

How should I store GABA?

You should store GABA 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 GABA?

The most common side effects of GABA 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.

• Low blood pressure (see below)
• Skin tingling (with higher doses)

There may be other side effects of GABA 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 GABA?

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

Severe Allergic Reactions. GABA may cause allergic reactions, which can be serious. Stop taking GABA 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

Low Blood Pressure (Hypotension). GABA may lower your blood pressure by a small amount, such as 5%-10%. For most people, this decrease in blood pressure is too small to cause symptoms. But if you already have low blood pressure or take GABA along with blood pressure medicines, your blood pressure may drop low enough to cause symptoms. If you feel faint or dizzy, lie down. Tell your health care provider right away if you have any of the following symptoms of low blood pressure.

• Dizziness, feeling lightheaded, or fainting
• Confusion
• Feeling weak or tired

Precautions

Who should not use GABA?

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

• Gamma-aminobutyric acid (GABA)
• Any of the ingredients in the specific product

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

What should I know about GABA before using it?

GABA is a dietary supplement. GABA may also be added to some foods, including fermented rice or fermented milk. None of these products can be marketed to treat or cure a disease.

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

Keep GABA out of the reach of children.

GABA may be found in dietary supplements that contain many other ingredients. Check the label to see what ingredients the product has, and ask your health care provider if you have questions or concerns.

Some people take GABA to help with anxiety. If you are having persistent anxiety, do not try to treat these symptoms on your own. Talk to your health care provider about your treatment options.

Some people take GABA to help with trouble sleeping (insomnia). If you have insomnia, it is important to make sure that you have the right sleeping conditions and good sleep-related habits. This is known as good sleep hygiene. Learn more about sleep hygiene here.

Very high doses of GABA, such as 5 grams or more, may cause a burning feeling in the throat or shortness of breath. In most cases, these side effects go away on their own. The lower doses of GABA found in most supplements are not expected to cause these effects.

The FDA has not tested GABA 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 GABA?

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 GABA 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.

• Anxiety
• High or low blood pressure

Other Medicines and Supplements.GABA may interact with other medicines and supplements. Before taking GABA, 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 GABA 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 GABA passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does GABA interact with foods or drinks?

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

It is unknown if drinking alcohol will affect GABA.

Does GABA 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 GABA.

• A medicine for high blood pressure
• L-theanine, which is an amino acid
• Phosphatidylserine, which is a supplement that is sometimes used for brain health

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

Dosing

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

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

GABA is naturally found in various foods and may also be added to some foods, including fermented food products. It is also available as a dietary supplement in a wide range of doses. Read the product label closely, and speak with a health care provider about how to take GABA safely. Do not take double or extra doses, even if you miss a dose.