... acid hydrochloride or 4-amino-3-phenylbutyric acid hcl,beta-phenyl-GABASynonyms: beta-phenyl- gamma-aminobutyric acid, fenibut, phenigamma Phenibut is ... is similar to GABA, baclofen (p-Cl-phenibut), and beta-phenylethylamine (PEA). GABA is the primary inhibitory neurotransmitter in the ... anxiety in high enough amounts. Phenibut is a GABA receptor agonist and also causes the release of GABA. Similar to ...