Henry R. Harrower was a manufacturer and dispenser of organotherapeutic products that were produced at the Harrower Laboratory in Glendale, California. Harrower developed a product, called Pan-Secretin Co. (Harrower), for use in treating diabetes that was administered orally. In this article Harrower describes glandular preparations for the treatment of diabetes other than insulin. His main focus is those preparations that can be taken orally and the priority of the discovery of insulin. Mentions Sir E. S. Schafer, Zuelzer, R. L. Mackenzie Wallis, and Pancreatin.