A lancet has a generally tubular body (1). A hollow insert (4) with a closed end plugs one end of the body (1), and it has a co-axial projection (5) forming a sharp tip proud of that end of the body. The body (1) and insert (4) are simultaneously formed by twin shot moulding, the body being of polyethylene and the insert being of a liquid crystal polymer which will create a sharp tip of adequate strength.