Two-electrode voltage clamp technique is used to characterize the functional properties of the major anxiolytic kavalactone, Kavain at human recombinant α1β2, β2γ2L, αxβ2γ2L, α1βxγ2L and α4β2δ γ-Aminobutyric acid type A receptors (GABAARs) expressed in Xenopus oocytes. Kavain positively modulates all receptors regardless of the subunit composition, but the degree of enhancement is greater at α4β2δ than at α1β2γ2L GABAARs. The modulatory effect of Kkavain is unaffected by flumazenil, indicating that Kavain does not enhance GABAARs via the classical benzodiazepine binding site. The β3N265M point mutation which has been previously shown to profoundly decrease anaesthetic sensitivity, also diminishes Kavain-mediated potentiation.