After completing high school Kendall attended Columbia University where he took three degrees in chemistry, including a Doctor of Philosophy under the guidance of Henry C. Sherman, a food chemist who directed his research on pancreatic amylase.
In a position with the pharmaceutical firm Parke, Davis, and Company, in 1910 Kendall sought to study the isolation of the active compound in the thyroid gland. In 1911 in New York City he pursued similar work at St. Luke's Hospital in Manhattan. He left the latter position in 1913, feeling that his employer did not appreciate the role of a research chemist.
Early in 1914, Kendall joined the Mayo Clinic in Rochester, Minnesota, where there was considerable success in thyroid surgery. Kendall, the clinic's only research chemist, was charged with isolating and studying the properties of the active substance in the thyroid gland. By 1914, he had prepared crystalline thyroxin and sought to learn its formula. During the next several years the pure thyroxin, an iodine compound, also received clinical trials which were successful in treating certain goiters. In 1926, he submitted a paper reporting its formula and structure for publication in the Journal of Biological Chemistry. Before the paper could be published, he learned that this had already been reported by Charles R. Harington of University College in London, England. Harington reported that the molecule contained four iodine atoms, not three, and had a somewhat different molecular structure; he proved to be correct.
Kendall now turned to the study of biological oxidations, giving particular attention to glutathione, a peptide which had been discovered in England in 1921. Kendall prepared crystalline glutathione and established its composition and structure correctly as glutamyl-cysteinyl-glycine, but pursued no further work on it. The two decades following 1930 at the Mayo Clinic were occupied with discovering the relation between the hormones in the adrenal cortex and the incurable Addison's disease. The first half of this period was spent in studying the nature of various fractions of the adrenal gland after epinephrine (trademarked as "adrenalin" by Parke Davis) was well known and in clinical use.
The newly created Institute of Experimental Medicine was correlated with the clinic's objectives. Kendall's research group had now grown to substantial size with temporary fellowships and a flow of professional visitors. The investigation of the hormones of the adrenal cortex included the weekly processing of 900 pounds of adrenal glands obtained from slaughtered beef. Over a fifteen-year period, the glands were shipped to Rochester, Minnesota, by Wilson Laboratories (subsidiary of the Wilson Packing Company) of Chicago. As part of the arrangement, epinephrine was separated from the medulla of the gland and sent free of charge to the Parke Davis company for processing and sale as adrenalin. The hormones processed from the cortex of the adrenal glands were used partly for clinical use in the Mayo Clinic, and partly for isolation and study of the several corticoid hormones by Kendall and his research associates. Research groups at Princeton and Columbia Universities, and in Zurich, reported the separation of seven crystalline compounds in 1936. Tadeus Reichstein and his group at the Technische Hochschule in Zurich reported isolation of seven crystalline compounds in 1936. By then Kendall's group had obtained five crystalline substances from their corticoid fractionations. These were identified for the moment as A, B, C, D, and E. The publication of Reichstein's work led to complications for both Zurich and the Mayo Clinic.
Reichstein's laboratory was an academic research operation that had sufficient staff to concentrate on synthesis and proof of structure of the various crystalline compounds; however, he had poor connections with clinical facilities. Conversely, Kendall's laboratory was associated with a clinic eager to test his compounds even before their formulas were established--but he and his staff were not as skilled in proof of structure as Reichstein's. By 1944, research on Compound A had enough negative effects in clinical tests that most studies on it were abandoned with respect to Addison's disease, and attention was focused on Compound E. In late 1944, Lewis H. Sarett of Merck and Company produced a few milligrams of E, and by 1945, the compound was being produced in amounts that encouraged clinical testing. Dr. Philip Hench, a physician in the Mayo Clinic, began making tests on patients with rheumatoid arthritis. Late in 1948, he injected the compound--which he and Kendall would soon name "cortisone"--into a woman with rheumatoid arthritis who went into remission as long as cortisone was available. Further tests were begun on other patients as soon as larger supplies of cortisone became available to Hench. The results appeared to be favorable, in that there was temporary remission of arthritic symptoms, and Hench and Kendall were in high spirits.
Cortisone received much publicity, and it soon became available in quantity as synthesis increased at Merck. It was hailed as a wonder drug and used not only for treatment of rheumatoid arthritis, but for a host of other ailments. The medical profession slowly came to realize that it had to be used in limited amounts and with great caution. Dr. Kendall retired from the Mayo Clinic in 1951 and became a visiting professor at Princeton University in New Jersey. Soon thereafter he developed a new research program at the James Forrestal Research Center near Princeton, where he sought without success to produce new medicinal agents. He led an active life to the end. The coronary failure which took his life occurred during a consulting trip to Merck and Company in May 1972.
Edward Kendall married Rebecca Kennedy on December 30, 1915, and they had four children.