Having it on an empty tummy can hasten absorption, but some want food to cut back headaches and nausea especially in very first time end users.GABA-B Receptor Agonist: The main system of motion of phenibut is as an agonist at the GABA-B (gamma-aminobutyric acid kind B) receptors. GABA is the principal inhibitory neurotransmitter while in the Mind,