Richet, Charles Robert (1850-1935) was a French physiologist, a scientist who studies how living things function. He won the 1913 Nobel Prize in physiology or medicine in recognition of his work on anaphylaxis, a rare, life-threatening allergic reaction that affects the whole body. The reaction develops rapidly after two or more exposures to an allergen (substance that causes an allergic reaction).

Richet was born on Aug. 26, 1850, in Paris. He received a medical degree in 1877 and a doctor of science degree in 1878, both from the University of Paris. Following graduation, he worked at the College de France and at the Faculty of Medicine at the University of Paris. From 1887 to 1927, he was a professor of physiology at the University of Paris. During the 1880's, Richet studied how warm-blooded animals maintain a constant body temperature and how bacteria are carried in body fluids. In the 1890's, he did research on tuberculosis.

In 1900, Richet began to study toxin (poison) from the Portuguese man-of-war, a tropical jellyfish. Experimenting with dogs, Richet found that certain animals that had survived a first dose of the toxin showed an extreme allergic reaction and died after a second, smaller dose of the toxin. He called this severe reaction anaphylaxis. It also became known as anaphylactic shock. Richet explained his findings in the book Anaphylaxis, published in 1911.

During World War I (1914–1918), Richet studied problems in the transfusion of blood plasma. He was editor of the Revue scientifique (Scientific Review) for 24 years. His varied writings also included poems, novels, and plays. Richet received the Cross of the Legion of Honor in 1926. He died in Paris on Dec. 4, 1935.