Novel erythropoiesis stimulating protein (NESP) is a hyperglycosylated analogue of recombinant human erythropoietin (rHuEPO) that stimulates erythropoiesis by the same mechanism as the native hormone. The addition of two extra carbohydrate chains, however, gives NESP greater metabolic stability in vivo, and its terminal half-life after IV administration is three-fold longer than for IV rHuEPO. This allows injections of both IV and SC NESP to be given less frequently, and indeed studies have shown that once-weekly, and even once every other week, dosing can maintain the hemoglobin concentration in patients treated for renal anemia. The optimum starting dose is 0.45 microg/kg once weekly via the IV and SC routes of administration. Adverse effects are very similar to those seen with rHuEPO, and no antibodies have been detected in over 1,500 patients exposed to NESP thus far. NESP therefore represents a triumph for drug synthesis by recombinant DNA technology, and we can look to the future of this new therapeutic agent with much hope and expectation.