Gamma-Aminobutyric acid (GABA) is an amino acid produced naturally in the brain. GABA functions as a neurotransmitter, facilitating communication among brain cells. GABA’s big role in the body is to reduce the activity of neurons in the brain and central nervous system, which in turn has a broad range of effects on the body and mind, including increased relaxation, reduced stress, a more calm, balanced mood, alleviation of pain, and a boost to sleep. (1)
First of all, GABA boosts the release of growth hormones by improving the quality of sleep since nighttime growth hormone release is linked to sleep quality and depth. (2, 3) It shortens sleep latency and increases non-rapid eye movement (REM) sleeping time. (4) GABA also reduces acute psychological and physical fatigue by suppressing sympathetic response and increasing parasympathetic response under stressful tasks.
(5, 6) Experts estimate that as much as 75 percent of the human growth hormone is released during sleep, especially during the first phase of slow-wave sleep. (7) In fact, GABA elevates resting and postexercise irGH (Immunoreactive growth hormone) and ifGH (Immunofunctional growth hormone) concentrations.
A study asked 21 healthy males to take a supplement with whey protein or whey protein plus GABA once a day for 12 weeks. The researchers found that the combination of whey protein and GABA increased levels of growth hormone compared to whey protein alone. (8) After GABA ingestion elevated peak concentrations of both hormones by about 400%. (9) One study showed the person who was given 300mg of GABA before going to bed fell asleep faster than those who took a placebo.
The GABA users also reported better sleep quality after one month of using the supplement. (10)
In addition, GABA supplements might help to build muscle and assist in workout recovery. GABA also has partly promoted muscle protein synthesis, leading to an increase in whole-body fat-free mass by elevating resting plasma GH concentrations.
Oral GABA supplementation promotes protein synthesis in various parts (e.g. the brain and gastrocnemius muscle) and higher plasma GH concentrations at rest in rats. (11)
High levels of GABA have also been linked to high intelligence and cognitive performance in a brain imaging study of healthy people. (12) For example, a 2015 study found that taking 800 milligrams (mg) of GABA supplementation per day enhanced a person's ability to prioritize and plan actions.
(13) Also, research shows that GABA might play a key role in protecting against depression and anxiety. For instance, a study published in the journal Biological Psychiatry in 2010 indicates that people with major depression may be more likely to have low levels of GABA. (14) And a 2009 study showed that increasing GABA levels may be useful in the treatment of conditioned fear.
These results are consistent with the fact that GABA is the primary calming (inhibitory) neurotransmitter in the brain. (15) Another study found that taking 100 mg of GABA daily helped reduce stress due to mental tasks. (16)