Béchamp was born in Bassing, France in 1816, the son of a miller. He lived in Bucharest, Romania from the ages of 7 to 18 with an uncle who worked in the French ambassador's office. He was educated at the University of Strasbourg, receiving a doctor of science degree in 1853 and doctor of medicine in 1856, and ran a pharmacy in the city. In 1854 was appointed Professor of Chemistry at the University of Strasbourg, a post previously held by Louis Pasteur. In 1856, after receiving his medical degree, Béchamp took a position at the University of Montpellier, where he remained until 1876 when he was appointed Dean of the Catholic Faculty of Medicine at Université Lille Nord de France. Béchamp's time in Lille was stormy, as his dispute with Pasteur led to efforts to have his work placed on the Index Librorum Prohibitorum (the index of books prohibited by the Catholic Church). Béchamp retired under this cloud in 1886, briefly ran a pharmacy with his son, and ultimately moved to Paris, where he was given a small laboratory at the Sorbonne. He died at the age of 91, his work having faded into scientific obscurity and Pasteur's version of germ theory dominant. A brief obituary in the British Medical Journal noted that Béchamp's name was "associated with bygone controversies as to priority which it would be unprofitable to recall."
In the modern day, Béchamp's work continues to be promoted by a small fringe of alternative medicine proponents (also known as germ theory denialists), including advocates of alternative theories of cancer, who dismiss Pasteur's germ theory and argue that Béchamp's ideas were unjustly ignored. They accuse Pasteur of plagiarising and then suppressing Béchamp's work, citing work such as Ethel Douglas Hume's Béchamp or Pasteur: A Lost Chapter in the History of Biology from the 1920s.