GABA, or gamma-aminobutyric acid, is such an important neurotransmitter that your brain would rather make it itself rather than bring it in from the outside. Nature has erected a barrier between the central nervous system and the bloodstream that limits what may cross over. While GABA may be crucial to the growth and development of your nerve cells and your mental health, the barrier will keep it from passing through. Though their effectiveness is questionable, oral GABA dietary supplements are available. Consult with your physician first before you start taking GABA or GABA-like supplements.
Leaky Brain Barrier
A healthy blood-brain barrier is an impenetrable gate. Bacteria, toxins and the supplemental GABA you ingested should never get a chance to reach vital brain tissues. There may be some tiny holes in the dike, however. Under certain circumstances, a small amount of GABA can cross from the brain into the bloodstream. The researchers of a 2001 study published in the "Journal of Neurochemistry" suggest that the body limits GABA levels in the brain by transporting it out of the central nervous system and into the bloodstream through a special one-way pump.
Gaba and Growth Hormones
GABA may also sneak into the the brain through an unlocked door: the pituitary gland. The researchers of another study published in "Medicine and Science in Sports and Exercise" in 2008 found that oral GABA supplements elevated growth hormone levels. Growth hormone is produced by the pituitary gland, which located in the brain but not isolated by the barrier. Because the pituitary has a foothold in both environments, it may provide the path that GABA can take to enter the central nervous system.
Supplemental GABA Derivitives
Though nature may limit GABA from crossing the barrier, chemists have found a way to create GABA-like supplements or analogues that can cross the barrier and function like GABA in the brain. Phenibut, or beta-phenyl-gamma-aminobutyric acid Hcl, is a designer GABA analogue. Chemists added a 6-carbon ring to GABA that enables it to cross the barrier and act on GABA receptors. Another GABA analogue supplement is picamilon, or nicotinoyl-GABA. Picamilon is made by adding niacin to the GABA molecule. Once picamilion crosses the barrier, the niacin molecule is cleaved off, leaving pure GABA.
Prescription GABA Derivitives
Because of its importance as a neurotransmitter, pharmaceutical manufacturers have worked to design prescription GABA analogues that can cross the blood-brain barrier and mimic GABA. Gabapentin is a GABA analogue used to treat epilepsy and neurotic pain. Gabapentin causes an increase in GABA levels in the brain. Another GABA analog is gamma-hydroxybutyrate, or GHB. Also known as "liquid ecstasy" and the "date rape drug," GHB is available in the U.S. as the prescription narcolepsy treatment Xyrem. Its generic name is now sodium oxybate.