A metering pump for the direct metering of active compounds, in particular for agricultural technology, includes having at least one housing with a delivery space, a reciprocating element, which bounds the delivery space at least on one side and is arranged movably in the housing, at least one suction valve connected in terms of flow to the delivery space, and at least one outlet valve connected in terms of flow to the delivery space. The reciprocating element is designed as a piston which can be displaced between two end positions, and an elastic ring is provided between housing and piston, which ring is at least partially compressed in both end positions of the piston.