The Effects of a GABA Deficiency and How You Can Test for It

Neurotransmitters are chemicals your brain requires to operate. Along with dopamine and serotonin, GABA is a critical neurotransmitter that carries signals throughout the body. Known as gamma-aminobutyric acid, GABA is thought to play a critical role in relaxing nerve cells. This calming effect influences many things, including sleep, stress and anxiety.

In addition, some studies have shown that GABA may play a key role in maintaining normal blood pressure and helping to improve mental health conditions like major depressive disorder and bipolar mood disorder.

Understanding the Role of GABA

Researchers are still uncovering the numerous ways GABA impacts your health. The two areas that have been broadly examined are sleep and mental health. According to the United States Pharmacopeia, which conducted a safety review of GABA, scientists are looking at GABA’s potential health benefits as an antidepressant, sedative, antihypertensive, antidiabetic, anticarcinogenic and immune system enhancer.

GABA and Sleep

GABA is one of the two main neurotransmitters that facilitate sleep. “A number of important brain areas use GABA to actively suppress wakefulness,” says Dr. Logan Schneider, clinical lead for sleep health at Alphabet and clinical assistant professor at the Stanford Sleep Center. “There is two-way communication between sleep and wake centers in the brain that ensure normal sleep patterns throughout the day and night.”

One small study found that GABA levels in the brain were almost 30% lower in patients with primary insomnia, which is sleeplessness that cannot be attributed to an existing medial, psychiatric or environmental cause.

GABA and Mental Health

The connection between neurotransmitters and mental health has been well established. However, the research constantly evolves on how neurotransmitters specifically affect mental health. A growing body of evidence suggests that the GABA neurotransmission system may play a central role in the development of depressive disorders — most especially postpartum depression disorder and certain neuropsychiatric conditions such as premenstrual dysphoric disorder.

A large body of work, ranging from biochemical to genetic studies, points to the importance of certain GABA receptors in mediating the effects of alcoholism in the central nervous system. GABA is stimulated by alcohol and an abrupt withdrawal of this GABA stimulation can result in an over-excited nervous system that can lead to withdrawal symptoms such as anxiety, headache, insomnia and nausea.

[READ: Ready for a Mental Health Workout?]

Testing for GABA Deficiency

GABA deficiency is not a recognized deficiency like vitamin D or B-12 deficiencies. There are no blood tests available that assess GABA deficiency. The highest concentrations of GABA are found in cerebrospinal fluid, which requires an invasive procedure called a lumbar spinal tap to measure the fluid. Scientists are still unraveling exactly how neurotransmitters interact and influence each other, so even if someone suspects they have a low GABA level, there are other neurotransmitters that could be contributing to the issue.

Biomarker testing is available, which can assess normal or elevated levels of GABA. “This type of testing can assess other biomarkers or molecules in the GABA pathway that may be helpful in detecting levels of GABA,” says Sarah Elsea, professor of molecular and human genetics at Baylor School of Medicine in Houston. “This is an indirect measurement because low levels of these biomarkers have not been fully investigated and are an area of ongoing research.”

According to Schneider, “GABA is so important to so many functions that people aren’t likely walking around with GABA deficiencies that they are not aware of because they would likely have severe neurologic dysfunction.”

Sub-optimal GABA levels may contribute to a person’s insomnia or depression, but there are too many other contributing factors that could play an important role. Not enough research has been done to conclude that low GABA levels play enough of a role to warrant therapy.

[Read: How to Stop Overthinking and Reduce Anxiety]

Do GABA Supplements Work?

Given the growing awareness of the role that GABA plays in many health conditions, there has been increasing interest in determining if someone may have sub-optimal GABA levels and finding ways to increase the body’s GABA levels via food, supplementation or medicine.

Sources of GABA in Food

GABA can be found in some uncooked foods such as:

Fermented foods, such as kimchi and sauerkraut.

— Japanese green tea leaves.

— Spinach.

— Some germinated beans, such as soybeans and adzuki beans.

— Sprouted grains.

GABA supplements are available at food stores and pharmacies. However, the health benefits of taking these supplements is not yet understood. Importantly, it has not been determined how much, if any, can pass the blood-brain barrier — so the health effects are unknown. The blood-brain barrier is a network of blood vessels and tissue that allows only some molecules to pass to and from the brain.

GABA supplements have been marketed for many uses, among them to relieve anxiety, increase lean muscle mass, elevate mood, stabilize blood pressure and relieve pain. A small, 40-person study on the safety and efficacy of GABA on patients with insomnia symptoms showed that after four weeks of supplementation (via 300 mg of GABA extracted from unpolished rice germ), the time it took patients to fall asleep decreased and sleep efficacy increased compared to placebo.

Other small studies have shown that GABA is associated with a transient decrease in blood pressure.

[READ: Acupuncture for Insomnia: How Acupuncture Can Help You Sleep.]

Safety of GABA Supplements

According to Elsea, toxicity and side effects appear to be low with GABA supplements. “This may be due to the limited ability of GABA to cross the blood-brain barrier,” she notes.

The USP Safety Review of GABA concluded in 2021 that the reviewed clinical studies did not associate any serious adverse events with the use of GABA supplements. However, there is not a recommended dose for GABA. The report showed no serious adverse reactions at dosages of 120 mg daily for 12 weeks. Mild to moderate side effects were reported, including headache, drowsiness and temporary burning sensation in the throat, among others.

Currently there is no long-term data on the effects of GABA during pregnancy and lactation, so speaking with your doctor is very important as researchers have noted that GABA can conceivably affect neurotransmitters and the endocrine system that controls growth hormone and prolactin levels.

More from U.S. News

6 Foods for Better Sleep

Steps to Fall Asleep Fast

Top Medications That Can Make You Tired

The Effects of a GABA Deficiency and How You Can Test for It originally appeared on

Update 03/03/23: This story was previously published at an earlier date and has been updated with new information.

More from WTOP

Log in to your WTOP account for notifications and alerts customized for you.

Sign up