In general, GABA does not cross the blood–brain barrier ,  although certain areas of the brain that have no effective blood–brain barrier, such as the periventricular nucleus , can be reached by drugs such as systemically injected GABA.  At least one study suggests that orally administered GABA increases the amount of human growth hormone (HGH).  GABA directly injected to the brain has been reported to have both stimulatory and inhibitory effects on the production of growth hormone, depending on the physiology of the individual.  Certain pro-drugs of GABA (ex. picamilon ) have been developed to permeate the blood–brain barrier, then separate into GABA and the carrier molecule once inside the brain. This allows for a direct increase of GABA levels throughout all areas of the brain, in a manner following the distribution pattern of the pro-drug prior to metabolism. [ citation needed ]
One of the many reasons I recommend that people get their protein from meat, seafood, or eggs, as opposed to whey protein supplements, is that I consider these foods to have a superior nutrient profile. Protein-rich whole foods have a lower protein density than whey protein powders, but contrary to what some people think, this is probably a good thing, at least from a health standpoint (As pointed out throughout this article). Moreover, if you eat fish, grass-fed meat, and eggs, you’re getting important nutrient (., essential fatty acids) that you don’t get from whey protein supplements.