What Is Gamma-Aminobutyric Acid (GABA)?

Written by Sadiya Ansari, Annie Stuart
Medically Reviewed by Jabeen Begum, MD on January 30, 2026
4 min read

GABA is a neurotransmitter that blocks impulses between nerve cells in the central nervous system (including your brain  and spinal cord). GABA can slow your brain down and may help lower stress, helping with better sleep. Low levels of GABA may be linked to:

Researchers suspect that GABA may boost mood or have a calming, relaxing effect on the nervous system.

People take GABA as a supplement to try to:

They may also take GABA to try to:

  • Ease pain or discomfort from injuries
  • Increase tolerance to exercise
  • Lower blood pressure
  • Burn fat
  • Boost the growth of lean muscle mass

Limited studies have shown a possible link between GABA and lowered blood pressure. But research on GABA supplements is lacking, and it is not yet certain whether it works for the many reasons people take it.

It is unclear whether GABA taken as a supplement reaches the brain in large enough quantities to have an effect. And currently, there is no set dosage for GABA.

You can get GABA naturally from foods. Some of the best food sources include:

  • Spinach
  • Sweet potatoes
  • Broccoli
  • Kale
  • Fermented foods, including tempeh and kimchi

Side effects. There has not been enough research to uncover the side effects of GABA supplements.

Risks. Overall, there isn't enough information to be sure about the safety of GABA. So, to be safe, avoid using GABA if you are pregnant or breastfeeding.

Interactions. Not enough is known about how GABA may interact with drugs, foods, or other herbs and supplements, but use with caution if you are also taking blood pressure medications.

Be sure to tell your doctor about any supplements you're taking, even if they're natural. That way, your doctor can check on any potential side effects or interactions with medications, foods, or other herbs and supplements. They can let you know if the supplement might raise your risks.

The FDA does regulate dietary supplements, but it treats them like foods rather than medications. Unlike drugmakers, the makers of supplements don't have to show their products are safe or effective before selling them on the market.

It's not clear whether taking GABA supplements can actually affect your brain. That's because there isn't enough evidence to show GABA can pass the blood-brain barrier, a protective layer that only allows certain types of molecules to enter the brain. "We don't know how GABA is processed in the gut and whether the GABA you take in really transfers to the brain," says Else Schneider, PhD, a senior researcher with the University Psychiatric Clinics Basel at the University of Basel in Switzerland.

While people take GABA to treat conditions like anxiety, it's unclear how GABA supplements are processed in the body. It's hard to say if there are any benefits of taking GABA as a supplement, Schneider says.

 

Since it's not known if supplements are effective, Schneider recommends getting GABA from food sources, which can have additional benefits. "Try to eat vegetables with GABA in them, and also try to eat as many different types of vegetables as you can," Schneider says. "That probably will have a bigger effect than only GABA."

Some vegetables that contain GABA include:

  • Brussels sprouts
  •  
  •  
  • Cauliflower
  • Cabbage
  • Broccoli

GABA is one of the most important neurotransmitters in our brains that plays a role in reducing stress and anxiety. Low levels of GABA are linked to depression, insomnia, and chronic pain. While people take GABA supplements for things like better sleep and relaxation, there isn't enough evidence to show that supplements can actually affect your brain. GABA also occurs naturally in many foods, and there is more research being done on how it can affect your gut. You can add fermented foods and vegetables such as kale and spinach to get more GABA in your diet. "It's more important to have a balanced diet than to take supplements," Schneider says.

How do you choose good-quality GABA?

Since GABA supplements have not been proven to pass into the brain, experts recommend getting GABA naturally from food. 

Are GABA supplements effective? 

There is not enough evidence to say GABA supplements are effective in reducing stress, improving sleep quality, or treating medical conditions.

Can GABA levels be affected by the intensity of exercise?

Exercise has been shown to maintain and/or boost GABA levels, with limited evidence that high-intensity exercise increases it more, but more research needs to be done to explore the connection between GABA and exercise.