An applicator for external action formulations is shown, and in particular a disposable applicator for formulations combatting ectoparasites of humans and animals is shown, including at least one formulation container (2) provided with a dispensing outlet (21). In order to protect the patient against possible injury during the application of the formulation, the applicator (1) also includes a plastic cap (3) having a form of a convex solid shell provided with a domed tip end (31) with a dispensing opening (32) which in the working mode of the applicator (1w) surrounds the dispensing outlet (21) of the formulation container (2), and connecting means (23, 34) which in the working mode of the applicator (1w) secure the cap (3) on the formulation container (2).