Gamma Amino Butyric Acid (GABA) has received much attention as a potential chemical to increase the production of Human Growth Hormone (HGH) and the promotion of lean muscle growth. There has been quite a bit of research on these claims, but not much measurable evidence to support the effectiveness of using GABA to increase HGH.
Gamma Amino Butyric Acid and HGH Studies
In the May 2002 edition of Neuroendocrinology, researchers manipulated GABA receptors to determine what effect this might have on HGH production. The researchers used the pituitary gland in rats to complete their investigation.
Their results indicate by blocking GABA receptors, HGH production is decreased. Conversely, HGH production is stimulated by introducing baclofen, which is a GABA receptor agonist. Baclofen is a prescription medication that is used as a muscle relaxer. Baclofen activates GABA receptors in the brain and has the ability to cross the blood brain barrier.
The researcher's conclusion is GABA does act to control HGH levels. Does this mean oral GABA supplements will increase HGH levels in humans? Not exactly.
GABA and the Blood Brain Barrier
The issue lies in the ability of GABA to cross the blood brain barrier. There is limited research on this. NYU Langone Medical Center states that oral intake of GABA does not show increase in brain levels of GABA, presumably as GABA cannot cross the blood brain barrier.
As such, oral supplements are not effective in replicating the effects of naturally occurring GABA in the brain.
GABA-HGH and Bodybuilders
A study published in the May, 2003 edition of Medicine and Science in Sports and Exercise looked at HGH levels in body builders that were taking GABA supplements. The results indicate a dramatic increase in HGH levels when body builders took GABA supplements prior to a strenuous workout. GABA taken without exercise had no effect on HGH levels.
It was theorized that the strenuous exercise may be necessary for GABA to effectively cross the blood brain barrier and stimulate HGH production.
Additional Research Needed
There are many claims of GABA supplements increasing HGH levels and lean muscle tone. Unfortunately, the evidence does not support this. Oral GABA supplements may increase HGH levels when taken prior to strenuous exercise, but more research is needed to support this.
As with any supplement, you should always consult with a primary care provider before adding a supplement to your diet.