What Are GABA Supplements?

Gamma-aminobutyric acid—often referred to as GABA—is an amino acid and a neurotransmitter, a chemical responsible for carrying signals from one nerve cell to another. Specifically, GABA changes brain activity, producing a calming effect.

While GABA is a naturally occurring chemical in your brain, it’s also widely available as a supplement. However, in supplement form, only minimal amounts of GABA can actually cross the blood-brain barrier (BBB) and have any effect on the brain.

This article discusses what you should know about over-the-counter (OTC) GABA supplements—their potential uses, side effects, and interactions.

Note that this article is not about GABA agonists, such as chlormethiazole or Valium (diazepam), which are prescription medications and not OTC supplements.

Uses of GABA

Like many supplements, people may use GABA for various reasons. But there are several clinical trials assessing GABA for the following potential uses.

Sleep Quality

In a small study of 40 people with insomnia, 300 milligrams (mg) of GABA one hour before bed for four weeks improved sleep quality by reducing sleep latency (the time it takes to fall asleep). Further, well-designed studies are needed to confirm these results.

Stress

A study of 30 people suggested GABA-enriched oolong tea was linked with lower short-term stress scores than regular oolong tea. Larger, well-designed studies are needed to confirm these results.

Blood Pressure

There are numerous small studies about GABA’s effects on lowering blood pressure. However, the results are mixed. This may have something to do with each study's different GABA dosages and dosage forms—like soy sauce, fermented milk, and specific GABA tablets.

What Are the Side Effects of GABA?

As with many medications and supplements, side effects are possible with GABA.

Common Side Effects

Common side effects of GABA may include:

• Burning feeling in throat
• Slight shortness of breath
• Skin tingling sensation

While common, these side effects tend to go away within a few minutes.

Severe Side Effects

Presently, there are no studies that specifically assess GABA’s safety. But several clinical trials suggest that GABA isn’t linked to severe side effects, except for low blood pressure. You may feel faint with low blood pressure.

Severe allergic reaction is another serious side effect possible with any medication. If you’re having a severe allergic reaction to GABA, get medical help immediately. Symptoms may include breathing difficulties, itchiness, and rash. 

Call 911 if your symptoms feel life-threatening.

Precautions

Your healthcare practitioner may advise against using GABA if any of the following applies to you:

• Severe allergic reaction: If you have a severe allergic reaction to GABA or any of its components (ingredients), you shouldn’t take this medication.
• Inherited disorders of amino acid metabolism: GABA is an amino acid. It may not be appropriate for people with inherited disorders of amino acid metabolism. Speak with your or your child’s healthcare provider if you have questions before taking supplements.
• Pregnancy or breastfeeding: There are currently no studies about the effects and safety of GABA during pregnancy. There are also no clinical trials on GABA’s effects and safety in nursing infants. For this reason, take GABA with caution. Speak with your healthcare provider to help you weigh the benefits and risks of GABA while pregnant or breastfeeding. 
• Children: There is limited information about the effects and safety of GABA in children. Research on GABA in children is in progress. But with most GABA product labels, GABA supplements should only be used in adults.
• Blood pressure medications: GABA may lower your blood pressure. This may have additive effects with antihypertensives, such as Microzide (hydrochlorothiazide).
• Adults over 65: In a small randomized-controlled clinical trial of 60 older adults, some participants took GABA in fermented Laminaria japonica (a type of seaweed). While the researchers monitored for side effects, none were mentioned in the study. But some older adults may generally be more sensitive to medication side effects. For this reason, take GABA with caution.

Dosage: How Much GABA Should I Take?

Because there is limited information about GABA supplements, there are no guidelines on the appropriate dosage for any condition. If you choose to take a GABA supplement, follow the directions on the label.

What Happens If I Take Too Much GABA?

There is limited information about GABA toxicity and overdoses. Data has shown no serious adverse events associated with GABA at intakes up to 18 grams per day for four days and in longer studies at intakes of 120 milligrams per day for 12 weeks. However, high daily doses of GABA (5 to 10 grams) may result in a burning sensation in your throat and low blood pressure. The upper recommended intake is typically 3 grams per day—with no more than 750 milligrams per dose.

Talk with your healthcare provider before taking GABA—especially if you’re planning to take at least 300 milligrams per day for more than four weeks.

Interactions

Use caution when taking GABA with the following:

• Anti-seizure medications: In general, anti-seizure medications—like phenytoin—work by slowing abnormal activity in the brain. Since GABA also has a similar effect, it may interact with these medications.
• Blood pressure medications: GABA may lower your blood pressure. This may have additive effects with antihypertensives, such as Microzide (hydrochlorothiazide).
• Sleep-inducing medications: GABA improved sleep quality in a small randomized-controlled trial of 40 people. This effect may increase when combined with other similar medicines in mice.

It is essential to carefully read a supplement's ingredients list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.

How to Store GABA

Since storage instructions might vary for different supplement products, carefully read the directions and packaging label on the container. But, generally, keep your medications tightly closed and out of the reach of children and pets, ideally locked in a cabinet or closet. Try to store your medicines in a cool and dry place.

Discard after one year or as indicated on the packaging. Avoid pouring unused and expired drugs down the drain or in the toilet. Visit the FDA's website to know where and how to discard all unused and expired medications. You can also find disposal boxes in your area.

Please reach out to your healthcare provider if you have any questions about how to take care of your medications or supplements.

If you plan to travel with GABA, become familiar with your final destination's regulations. The U.S. Embassy or Consulate might be a helpful resource.

Similar Supplements

GABA is an amino acid. Other similar amino acids also available as supplements include:

• 5-hydroxytryptophan (5-HTP)
• L-tryptophan

Like GABA, 5-HTP and L-tryptophan have been researched for their potential use in relieving sleeping problems. This is because 5-HTP and L-tryptophan can turn into melatonin, which may have some effectiveness for certain sleeping conditions. Unfortunately, current research doesn’t support 5-HTP and L-tryptophan to help with sleep.

In the body, 5-HTP and L-tryptophan may also turn into serotonin, a naturally occurring brain chemical that affects mood. So, some people may also use 5-HTP and L-tryptophan for mood. However, there is little data to support this. Serotonin may also have some effect on blood pressure. Unlike GABA, serotonin may play a role in increasing your blood pressure. In fact, too much serotonin may result in a condition called serotonin syndrome—with high blood pressure as a symptom.

Sources of GABA & What to Look For

While GABA is available as an OTC supplement, there are other sources of GABA.

Food Sources of GABA

You can get natural sources of GABA through your diet. Examples of GABA-containing foods include:

• Bok choy
• Brussels sprouts
• Cabbage
• Cauliflower
• Collard greens
• Mushrooms
• Potatoes
• Rice
• Soybeans
• Tomatoes
• Watercress

Glutamic acid or glutamate is a precursor of GABA, meaning your body can use them to make GABA. Theoretically, increasing foods with glutamic acid or glutamate may increase GABA in the body. Glutamic acid may be obtained by eating meat, poultry, fish, eggs, dairy products, and select high-protein vegetable sources.

Drastic dietary changes may interact with your medications or affect your medical conditions. For this reason, talk with your healthcare provider first. They will help you safely make these changes.

GABA Supplements

GABA is available in many dosage forms, including capsules and tablets. If you have difficulty swallowing pills, GABA is available in the following dosage forms:

• Chewables
• Lozenges
• Liquids
• Powder

GABA also has vegan or vegetarian products.

Which supplement you choose primarily comes down to your preference and what you hope to get in terms of effects. Each product may work differently depending on the form, so following the directions is essential.

Summary

GABA is an amino acid. Very little GABA may cross the blood-brain barrier when taken in oral supplement form, leaving some scientists to think that some GABA supplements may work via the placebo effect (when your brain is able to convince your body that a substance is working).

Studies have suggested GABA relieves stress and improves sleep. GABA may also lower blood pressure. While GABA is available as an OTC supplement, it’s not without side effects. There are also possible interactions to consider. More research is still needed to assess GABA’s effectiveness and safety. Before taking GABA, talk with your pharmacist or healthcare provider to help you safely achieve your health goals.

Because there is limited information about GABA supplements, there are no guidelines on the appropriate dosage to take for any condition. If you choose to take a GABA supplement, follow the directions on the label.

GABA supplements are sold in pill and capsule form. You may also see the supplement sold as a powder. It's important to check the label if you choose to purchase these products because there may be a variety of ingredients listed on the package.

Before you buy any supplement, the National Institutes of Health (NIH) recommends that you look for a Supplement Facts label. This label provides important health information, including the number of active ingredients per serving. It will also tell you about other added ingredients like fillers, binders, and flavorings.

The NIH also suggests that you look for a product that contains a seal of approval from a third-party organization that provides quality testing. These organizations include:

• U.S. Pharmacopeia (USP)
• ConsumerLabs
• NSF International

A seal of approval from one of these organizations does not guarantee the product's safety or effectiveness. But it does provide assurance that:

• The product was properly manufactured.
• The product contains the ingredients listed on the label.
• The product does not contain harmful levels of contaminants.

GABA is an amino acid that may help improve your mood. Several studies show that increased GABA levels in the brain can help decrease anxiety, stress, and depression. But more research needs to be done to determine if GABA supplements are effective for treating any condition.

Look for supplements that contain a Supplement Facts label so you know what ingredients are inside them. You should also choose a supplement that has the seal of approval from a third-party organization that provides quality testing.