Side effects of gamma-aminobutyric acid, or GABA, include increased heart rate, rapid breathing, shortness of breath, drowsiness, and tingling, itching or tickling in the neck, face and limbs, states Nootriment.com. WebMD categorizes the drug as "likely safe" when taken in appropriate doses by mouth for up to 12 weeks.
Individuals commonly take the supplement to improve mood, relieve anxiety, improve sleep quality, aid with pre-menstrual syndrome and to treat attention-deficit hyperactivity disorder, explains WebMD. However, both Nootriment and WebMD state that there is little scientific evidence that GABA supplements are beneficial in the treatment of such disorders.
It is not possible to obtain the naturally-occurring amino acid through diet, but fruits, vegetables, teas and red wine contain substance that positively influence how GABA works in the brain, explains WebMD.