The present invention provides a puncture aid comprising a housing in which a lancet holder with a lancet is displaceably mounted, the lancet holder being connected to a spring element. The lancet holder has at least one bearing element and the housing has a support surface arranged such that the bearing element rests on the support surface in a first position of the lancet holder. A trigger unit is provided, actuation of which transfer the lancet holder to a second position by means of a relative rotational movement of the bearing element and the support surface, so that the bearing element falls from the support surface in the second position of the lancet holder, and the tensioned spring element at least partially relaxes and moves the lancet holder such that the tip of the lancet emerges from the opening of the housing. The puncture aid includes a blocking element which is arranged such that it blocks a relative rotational movement of the bearing element and the support surface with respect to one another after the trigger unit has transferred the lancet holder to the second position with the result that reuse of the puncture aid is prevented.