The lancet has a piercing element (1) for penetrating into skin of a patient, and a testing area with detection reagents for determining an analytic concentration of a body fluid sample. A capillary structure (3) is arranged in the piercing element for transporting the body fluid sample to the testing area. The capillary structure is blocked in a section that surrounds a sterile protection, where a component (6a) is made of polymer foam. An independent claim is also included for a method for manufacturing a lancet.