Jean-Louise Ferraud is a non-canonical character created for the 1993 ITV adaptation of The Chocolate Box. He is a pharmacist in Brussels and a personal friend of Hercule Poirot during the pre World War I era. When Poirot was investigating the death of Paul Déroulard, Ferraud helps Poirot by analysing bits of chocolate from a box belonging Déroulard and established that they contained trinitrine.
Poirot left Belgium during World War I. When he comes back to Brussels in the mid 1930s, he meets Ferraud again. By this time, Ferraud has married Virginie Mesnard whom Poirot had grown quite close to during the investigation.
Ferraud is also the pharmacist who supplied Gaston Beaujeu with his trinitrin medication. The label on the bottle shows that Ferraud's pharmacy is located on Boulevard du Jardin Botanique, an actual street in Brussels.
Jean-Louise Ferraud is portrayed by Jonathan Barlow. There is no such character in the original story. Poirot meets two pharmacists there but they are not named.