Gamma-aminobutyric acid, commonly called GABA, is an amino acid derivative that sends calming signals to your brain. At the time of publication, GABA is under study for use in the treatment of nerve disorders such as epilepsy and anxiety. Bodybuilders also use it to increase muscle growth. Doctors prescribe GABA in varying doses, but no safe dose has been established for taking GABA as a dietary supplement.
Some doctors prescribe GABA in doses of up to 200 milligrams, four times a day, for a maximum daily dose of 800 milligrams. GABA sold as a dietary supplement typically contains 500 to 750 milligrams of the neurotransmitter with recommendations to take it up to two times a day. If you took 750 milligrams twice daily, your intake would amount to nearly twice as much as the maximum daily dose prescribed by doctors.
Human Growth Hormone
On websites devoted to weightlifting and sales of GABA supplements, you may read claims that GABA boosts activity in your body’s human growth hormone. This is true of the GABA produced naturally in your body, but not necessarily of GABA taken as an oral supplement. Slight evidence does, however, support the theory that oral supplements of GABA stimulate HGH. In a study conducted at Shenandoah University in Virginia, researchers gave 11 men either 3 grams of GABA or a placebo. They found that GABA increased HGH levels by up to 400 percent, as noted in an article published in the January 2008 issue of “Medicine and Science in Sports and Exercise.”
Side effects of GABA include sleepiness, tingling and flushing. Side effects, which also include accelerated heart rate and difficulty breathing, may be more pronounced if you take high doses of GABA without exercising afterward. Pregnant women and anyone with kidney disorders should not take GABA. Do not take GABA with substances that affect its pathway to the brain. Examples include alcohol and barbiturates. In clinical settings, participants have taken up to 18 grams of GABA, but this doesn’t mean you can safely take this – or any – amount daily for long-term use.
Naturally occurring GABA is well studied. Its slows nerve activity in your brain. People with epilepsy, Parkinson's and anxiety disorders have lower than normal amounts of GABA. Further research is needed, however, to determine whether oral doses of GABA reach your brain and improve nerve-related conditions. Research about the safety of GABA supplements also remains slim, so talk to your doctor before taking it as a dietary supplement.