General Description
GABA is a naturally occurring amino acid found in the brain, where
it functions as a neurotransmitter, inhibiting neural excitation.1
While GABA is present in some green plants, yeasts, and bacteria,
and is also available as a dietary supplement, dietary sources are
not thought to significantly affect brain GABA levels, as the nutrient
is not transported efficiently from the bloodstream into the brain.
Most GABA found in the brain is manufactured there from the simple
sugar glucose and the amino acid glutamine.
Health Applications
- Muscle development
- Weight loss
- Stress/anxiety
Primary Uses
Although GABA supplements have been promoted for a wide variety
of benefits such as increasing lean muscle mass, reducing body
fat, reducing stress, and promoting sleep, there is little evidence
to support such claims. As dietary GABA does not readily cross
the blood/brain barrier, it is unlikely to influence mood or sleep
patterns. While some studies indicate that GABA supplements can
stimulate growth hormone and prolactin secretion,2,3
effects on muscle mass and body fat have not been demonstrated.
Dosage/Toxicity
Although a therapeutic dosage level for GABA has not been demonstrated,
a common recommendation is 200 mg, four times per day. Human studies
on GABA have used single doses of 5 grams with no overt signs
of toxicity.2,3 The long-term safety of GABA
supplementation is unknown. |
