Gamma-Aminobutyric acid or GABA is the primary inhibitory neurotransmitter in the human brain. In other words, GABA is responsible for reducing excitability in the brain, resulting in extreme relaxation and deep sleep. VPA’s GABA also has a strong ability to promote growth hormone production, increasing lean muscle tissue and fat burning. If that wasn’t enough, GABA also has anti-aging properties due to its growth hormone stimulation.