We have carried out an independent investigation of the lipase activity of several pancreatin preparations, including high-lipase preparations of pancreatin that have recently become available. Six preparations from three pharmaceutical companies, Cilag, Duphar, and Merck, were analyzed during the recommended shelf life of the preparation and included a standard and a high-lipase preparation from each manufacturer. All preparations studied showed lipase activity in excess of that which was stated on the packets, and in some cases it was more than twofold. This has important implications for patients and prescribers since changes in apparent enzyme requirements may reflect differences in the potency of batches with time. As it is impossible to evaluate capsule requirements with each new batch prescribed, the presence or relief of symptoms of malabsorption will probably continue to be the way in which most patients monitor their enzyme supplementation on a regular basis. We believe that clinicians need to be aware of the extent of possible intrinsic variation between individual prescriptions before attempting to define possible dose/symptom relationships.