Hormones: adrenaline, insulin, and "the pill" In 1901 Jokichi Takamine (1854–1922) isolated adrenaline. This was the first isolation of a hormone. Knowledge of hormones—substances the body creates to regulate its functioning—would lead to many medical breakthroughs. For example, in the early 1920s Frederick Grant Banting (1891–1941) and John James Rickard McLeod (1876–1935) isolated insulin, the hormone that regulates blood-sugar levels, and identified its deficiency as the cause of diabetes. Chemical modification of hormones would create other drugs, such as hydrocortisone, synthesized by Percy Lavon Julian (1899–1975) in 1948, and norethindrone, the first effective oral contraceptive, synthesized in 1951 by Carl Djerassi (1923– ). Later, in 1956, Gregory Pincus (1903–1967) and John Rock (1890–1984) developed the hormone progesterone into an oral contraceptive.