The present invention provides methods and apparatus permitting rapid and thorough hydration of an initially dry hydratable matrix element contained within an iontophoretic bioelectrode. The apparatus of the invention comprises a bioelectrode system for iontophoretic delivery of medicaments having at least one hydratable matrix element and associated removable hydration assembly. The preferred embodiment of the present invention comprises two hydratable matrix elements each having an associated removable hydration assembly and each being associated with an electrical current distribution element. The removable hydration assembly includes an initially sealed liquid-storage component which maintains the desired hydrating liquid in isolation from the hydratable matrix element until such time as hydration is desired. At that time, the removable hydration assembly can be activated by the user through application of force to an extending tab member attached to the sealed liquid-storage component thereby causing progressive unsealing of the sealed liquid-storage component and progressively depositing the hydrating liquid uniformly onto the entire surface of the hydratable matrix element. Following hydration of the matrix element, the spent hydration assembly can be withdrawn completely from within the bioelectrode system.