Background

• Gamma-aminobutyric acid (GABA) is a molecule that is the main chemical in the mammalian (warm-blooded vertebrate) central nervous system that helps balance mood. Most of the immediate effects of GABA related to the nervous system are controlled by the GABA(A) class of receptors, which function as a gate to let certain electrolytes pass only when GABA is attached to the receptor (GABA is like a key).
• Much research has focused on the effects of naturally occurring GABA in the body and agents (including drugs and herbs) that increase the effects of this chemical. Many dietary supplements that are used to improve memory and sleep, including 5-HTP, hop, kava, lemon balm, passionflower, skullcap, and valerian, influence GABA already present in the body.
• Synthetic GABA has been examined to treat nerve-, heart-, and brain-related disorders. Reports state that GABA is likely safe to use for short-term, low-dose treatments. Many mood disorders have been associated with low levels of GABA in the blood, which can be increased with supplementation. GABA is commonly taken to relax or sleep, and it may help improve mood disorders, although experts do not support the use of GABA for this purpose.
• GABA has also been shown to increase growth hormone (GH) secretion in humans when taken orally; thus, GABA is popularly used as a bodybuilding supplement. However, there is a lack of evidence to support the anabolic effects of GABA supplementation.

References

1. Abdou AM, Higashiguchi S, Horie K, Kim M, Hatta H, and Yokogoshi H. Relaxation and immunity enhancement effects of gamma-aminobutyric acid (GABA) administration in humans. Biofactors 2006;26(3):201-208. View Abstract
2. Cavagnini F, Invitti C, Pinto M, Maraschini C, Di Landro A, Dubini A, and Marelli A. Effect of acute and repeated administration of gamma aminobutyric acid (GABA) on growth hormone and prolactin secretion in man. Acta Endocrinol.(Copenh) 1980;93(2):149-154. View Abstract
3. Cho YR, Chang JY, and Chang HC. Production of gamma-aminobutyric acid (GABA) by Lactobacillus buchneri isolated from kimchi and its neuroprotective effect on neuronal cells. J.Microbiol.Biotechnol. 2007;17(1):104-109. View Abstract
4. Cocito L, Bianchetti A, Bossi L, Giberti L, and Loeb C. GABA and phosphatidylserine in human photosensitivity: a pilot study. Epilepsy Res. 1994;17(1):49-53. View Abstract
5. Elliott KA, Jasper HH. Gammaaminobutyric acid. Physiol Rev. 1959;39(2):383-406. View Abstract
6. Gamma-aminobutyric acid (GABA), Monograph. Altern.Med.Rev. 2007;12(3):274-279. View Abstract
7. Loeb C, Benassi E, Bo GP, Cocito L, Maffini M, and Scotto P. Preliminary evaluation of the effect of GABA and phosphatidylserine in epileptic patients. Epilepsy Res. 1987;1(3):209-212. View Abstract
8. Mishunina TM, Kononenko VI, Komissarenko IV, and Luchitskii EV. [The effect of GABA-ergic preparations on the function of the hypothalamo-hypophyseal-adrenal system in patients with Itsenko-Cushing disease]. Probl.Endokrinol.(Mosk) 1991;37(4):28-31. View Abstract
9. Nemeroff CB. The role of GABA in the pathophysiology and treatment of anxiety disorders. Psychopharmacol.Bull. 2003;37(4):133-146. View Abstract
10. Okita Y, Nakamura H, Kouda K, Takahashi I, Takaoka T, Kimura M, and Sugiura T. Effects of vegetable containing gamma-aminobutyric acid on the cardiac autonomic nervous system in healthy young people. J.Physiol Anthropol. 2009;28(3):101-107. View Abstract
11. Petty F. Plasma concentrations of gamma-aminobutyric acid (GABA) and mood disorders: a blood test for manic depressive disease? Clin.Chem. 1994;40(2):296-302. View Abstract
12. Shimada M, Hasegawa T, Nishimura C, Kan H, Kanno T, Nakamura T, and Matsubayashi T. Anti-hypertensive effect of gamma-aminobutyric acid (GABA)-rich Chlorella on high-normal blood pressure and borderline hypertension in placebo-controlled double blind study. Clin.Exp.Hypertens. 2009;31(4):342-354. View Abstract
13. Shoulson I, Kartzinel R, and Chase TN. Huntington's disease: treatment with dipropylacetic acid and gamma-aminobutyric acid. Neurology 1976;26(1):61-63. View Abstract
14. Yogeeswari P, Ragavendran JV, and Sriram D. An update on GABA analogs for CNS drug discovery. Recent Pat CNS.Drug Discov. 2006;1(1):113-118. View Abstract