He was a German physiologist born into a Jewish family.
He studied at the University of Munich and graduated in medicine from the University of Strasbourg. He soon gave up his medical practice to devote himself to research.
He taught classes, as assistant professor, at the University of Vienna and in 1909 obtained the chair of pharmacology at the University of Graz, but when the Nazis arrived his position was seized and he had to leave the country. After brief periods in Brussels and Oxford, he moved to New York in 1940, where he was appointed Professor at the New York University School of Medicine.
Loewi began his research based on a hypothesis by Elliot, who argued that a nerve impulse is transmitted through a chemical substance. Lowe was able to show that this substance in the parasympathetic nervous system was acetylcholine, a substance that Henry Hallett Dale had previously isolated. Both were awarded the Nobel Prize in Physiology or Medicine in 1936.
Lowe’s discovery gave rise to the chemical theory of nerve transmission, according to which a nerve current causes, at the end of a nerve fiber, to release a chemical called a neurotransmitter.