Last Updated: May 28, 2023

GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter. Although supplementation can increase growth hormone levels, the effects are short-lived. Some research has also reported beneficial effects on sleep quality, stress, and mood. However, results have been inconsistent across studies.

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GABA is most often used for

What is GABA?

GABA is the major inhibitory neurotransmitter in the central nervous system. It fulfills a number of functions in the brain and affects nonneuronal tissues outside the brain. GABA regulates many depressive and sedative actions and is critical for relaxation.[1][2][3][4] Consequently, several drugs that resemble the structure of GABA (e.g., baclofen, gabapentin, and pregabalin) have been developed to treat seizures and convulsions. GABA is also involved in the neural regulation of visual tasks and emotion processing.[5]

What are GABA’s main benefits?

In general, there is limited human research on oral supplementation with GABA. A few small studies have found improvements in sleep quality and markers of stress, as measured by questionnaires, heart rate variability, and cortisol, following supplementation with GABA, but other studies have not.[6] Therefore, it’s not currently possible to draw firm conclusions about the effect of GABA on these outcomes.

Some studies find that supplementation with GABA improves some aspects of visual attention[7] and mood during stressful tasks.[8] These effects might be relevant to people with schizophrenia and mood disorders because GABA levels in the brain and neural signaling processes activated by GABA are altered in these conditions.[9][10][6][11][12][13] However, studies determining the effect of supplementation with GABA in people with these conditions is currently lacking.

A single dose of GABA (1 gram) taken orally has been shown to blunt the rise in core temperature at rest and during exercise in the heat,[14][15] but it remains to be studied whether this effect can actually help improve exercise performance in the heat.

One resistance training intervention found that daily supplementation with whey protein (10 grams per day) and GABA (100 milligrams per day) increased fat-free mass more than whey protein alone,[16] but muscle strength was not affected. Further studies are needed to confirm this finding.

What are GABA’s main drawbacks?

Ingested GABA does not appear to reach the brain in appreciable amounts,[17][18][19][20] meaning oral supplementation can’t be assumed to replicate the effects of GABA as a neurotransmitter. However, the main drawback is that few studies have examined the effect of oral supplementation with GABA in humans. Furthermore, the specific effect of GABA is often difficult to determine because many human studies examine the effect of eating GABA-containing foods, like tea or rice, rather than the effect of oral supplementation with GABA alone.[6] Consequently, further clinical trials specifically using GABA are needed to fully understand its effects.

Oral supplementation with GABA appears to be fairly safe and well-tolerated, with no evidence of toxicity in animal studies[21][22] or serious side effects in human studies.[23][22][24][14][15][16][6] However, abdominal discomfort, headache, and drowsiness has been documented following supplementation with GABA.[25]

How does GABA work?

GABA exerts its various effects by binding to GABAA and GABAB receptors in the brain. GABA is also found outside the brain in nonneuronal tissues, including the pancreas, certain immune cells (e.g., lymphocytes), and the gastrointestinal tract. How GABA works outside the brain is an area of ongoing research.[1][2][3][4][4]

What else is GABA known as?
Note that GABA is also known as:
  • Gamma-Aminobutyric Acid
Dosage information

Supplemental GABA has been used in humans (for the purpose of enhancing growth hormone metabolism) in the dosage range of 3,000-5,000mg GABA. It is unsure if this is the optimal dosage.

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Update History
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  2. ^Sieghart W, Savić MMInternational Union of Basic and Clinical Pharmacology. CVI: GABA Receptor Subtype- and Function-selective Ligands: Key Issues in Translation to Humans.Pharmacol Rev.(2018-Oct)
  3. ^Ngo DH, Vo TSAn Updated Review on Pharmaceutical Properties of Gamma-Aminobutyric Acid.Molecules.(2019-Jul-24)
  4. ^Petroff OAGABA and glutamate in the human brain.Neuroscientist.(2002-Dec)
  5. ^Kiemes A, Davies C, Kempton MJ, Lukow PB, Bennallick C, Stone JM, Modinos GGABA, Glutamate and Neural Activity: A Systematic Review With Meta-Analysis of Multimodal H-MRS-fMRI Studies.Front Psychiatry.(2021)
  6. ^Piril Hepsomali, John A Groeger, Jun Nishihira, Andrew ScholeyEffects of Oral Gamma-Aminobutyric Acid (GABA) Administration on Stress and Sleep in Humans: A Systematic ReviewFront Neurosci.(2020 Sep 17)
  7. ^Leonte A, Colzato LS, Steenbergen L, Hommel B, Akyürek EGSupplementation of gamma-aminobutyric acid (GABA) affects temporal, but not spatial visual attention.Brain Cogn.(2018-Feb)
  8. ^Yoto A, Murao S, Motoki M, Yokoyama Y, Horie N, Takeshima K, Masuda K, Kim M, Yokogoshi HOral intake of γ-aminobutyric acid affects mood and activities of central nervous system during stressed condition induced by mental tasks.Amino Acids.(2012-Sep)
  9. ^Reddy-Thootkur M, Kraguljac NV, Lahti ACThe role of glutamate and GABA in cognitive dysfunction in schizophrenia and mood disorders - A systematic review of magnetic resonance spectroscopy studies.Schizophr Res.(2022-Nov)
  10. ^Kumar V, Vajawat B, Rao NPFrontal GABA in schizophrenia: A meta-analysis of H-MRS studies.World J Biol Psychiatry.(2021-Jan)
  11. ^Frajman A, Maggio N, Muler I, Haroutunian V, Katsel P, Yitzhaky A, Weiser M, Hertzberg LGene expression meta-analysis reveals the down-regulation of three GABA receptor subunits in the superior temporal gyrus of patients with schizophrenia.Schizophr Res.(2020-Jun)
  12. ^Romeo B, Choucha W, Fossati P, Rotge JYMeta-analysis of central and peripheral γ-aminobutyric acid levels in patients with unipolar and bipolar depression.J Psychiatry Neurosci.(2018-Jan)
  13. ^Schür RR, Draisma LW, Wijnen JP, Boks MP, Koevoets MG, Joëls M, Klomp DW, Kahn RS, Vinkers CHBrain GABA levels across psychiatric disorders: A systematic literature review and meta-analysis of (1) H-MRS studies.Hum Brain Mapp.(2016-Sep)
  14. ^Miyazawa T, Kawabata T, Okazaki K, Suzuki T, Imai D, Hamamoto T, Matsumura S, Miyagawa TOral administration of γ-aminobutyric acid affects heat production in a hot environment in resting humans.J Physiol Anthropol.(2012-Feb-29)
  15. ^Miyazawa T, Kawabata T, Suzuki T, Imai D, Hamamoto T, Yoshikawa T, Miyagawa TEffect of oral administration of GABA on temperature regulation in humans during rest and exercise at high ambient temperature.Osaka City Med J.(2009-Dec)
  16. ^Sakashita M, Nakamura U, Horie N, Yokoyama Y, Kim M, Fujita SOral Supplementation Using Gamma-Aminobutyric Acid and Whey Protein Improves Whole Body Fat-Free Mass in Men After Resistance Training.J Clin Med Res.(2019-Jun)
  17. ^Löscher W, Frey HHTransport of GABA at the blood-CSF interface.J Neurochem.(1982-Apr)
  18. ^Al-Sarraf HTransport of 14C-gamma-aminobutyric acid into brain, cerebrospinal fluid and choroid plexus in neonatal and adult rats.Brain Res Dev Brain Res.(2002-Dec-15)
  19. ^K Kuriyama, P Y SzeBlood-brain barrier to H3-gamma-aminobutyric acid in normal and amino oxyacetic acid-treated animalsNeuropharmacology.(1971 Jan)
  20. ^A KrantisThe involvement of GABA-transaminase in the blood-brain barrier to radiolabelled GABAActa Neuropathol.(1984)
  21. ^Takeshima K, Yamatsu A, Yamashita Y, Watabe K, Horie N, Masuda K, Kim MSubchronic toxicity evaluation of γ-aminobutyric acid (GABA) in rats.Food Chem Toxicol.(2014-Jun)
  22. ^Oketch-Rabah HA, Madden EF, Roe AL, Betz JMUnited States Pharmacopeia (USP) Safety Review of -Aminobutyric Acid (GABA).Nutrients.(2021-Aug-10)
  23. ^Martin A, Mick GJ, Choat HM, Lunsford AA, Tse HM, McGwin GG, McCormick KLA randomized trial of oral gamma aminobutyric acid (GABA) or the combination of GABA with glutamic acid decarboxylase (GAD) on pancreatic islet endocrine function in children with newly diagnosed type 1 diabetes.Nat Commun.(2022-Dec-24)
  24. ^Yoon S, Byun JI, Shin WCEfficacy and Safety of Low-Dose Gamma-Aminobutyric Acid From Unpolished Rice Germ as a Health Functional Food for Promoting Sleep: A Randomized, Double-Blind, Placebo-Controlled Trial.J Clin Neurol.(2022-Jul)
  25. ^Byun JI, Shin YY, Chung SE, Shin WCSafety and Efficacy of Gamma-Aminobutyric Acid from Fermented Rice Germ in Patients with Insomnia Symptoms: A Randomized, Double-Blind Trial.J Clin Neurol.(2018-Jul)
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  30. ^Hedrington MS, Mikeladze M, Tate DB, Younk LM, Davis I, Davis SNEffects of γ-Aminobutyric Acid A Receptor Activation on Counterregulatory Responses to Subsequent Exercise in Individuals With Type 1 Diabetes.Diabetes.(2016-Sep)
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  32. ^Cavagnini F, Invitti C, Di Landro A, Tenconi L, Maraschini C, Girotti GEffects of a gamma aminobutyric acid (GABA) derivative, baclofen, on growth hormone and prolactin secretion in man.J Clin Endocrinol Metab.(1977-Sep)