1914: The Discovery of Thyroxin #throwbackthursdays


Some medical discoveries truly stand the test of time. The case of a dedicated Mayo Clinic chemist is a prime example. Feeling he was on the verge of a breakthrough that could help countless people, Edward Kendall, Ph.D., spent Christmas Eve 1914 locked away in his laboratory. What he accomplished by Christmas morning was a gift to millions, one that is still improving lives 100 years later.

John Morris III, M.D., Endocrinology/Molecular Medicine, explains, “Levothyroxine, the name for synthetically made thyroid hormone, is the most commonly prescribed medication in the U.S.”

The thyroid is a butterfly-shaped gland that resides just below the Adam’s apple. Unless it acts up, you probably never give it a thought. Problem is, it acts up for a lot people. Dr. Morris is a gland specialist, called an endocrinologist. He says a thyroid’s main purpose is making essential hormones. Dr. Morris states, “About 8 to 10 percent of women in the U.S. will have thyroid disease or dysfunction at some point in their life and 2 or 3 percent of men, perhaps more.”

Dr. Kendall was a young chemist from New York, who was obsessed with unlocking the thyroid’s secrets. So, in the southwest corner of the brand new and aptly named 1914 Building, Kendall set up his laboratory and made good progress during his first summer and fall at Mayo Clinic, purifying thyroid compounds.

“And, actually, as the story goes, he came in on Christmas Eve in 1914 to do one additional round of purification and to try to crystallize this newest preparation,” says Dr. Morris. “On Christmas morning, he went in to the laboratory, and he had crystal powders of purified thyroid hormone — the first time the hormone from the thyroid, that we now call thyroxin, had been purified.”

The discovery is the reason so many people have this potentially lifesaving medication today.

Kelley Luedke

Kelley Luedke

Kelley Luedke is a Marketing Channel Manager at Mayo Clinic Laboratories. She is the principle editor and writer of Insights and leads social media and direct marketing strategy. Kelley has worked at Mayo Clinic since 2013. Outside of work, you can find Kelley running, traveling, playing with her kitty, and exploring new foods.