Etifoxine was developed by Hoechst of Germany in the 1960s. It was originally believed to be a mild benzodiazepine, because it didn’t sedate and scientists at the time did not have the technology to measure its true efficacy or determine its actual mechanism of action.

Accordingly, it was deemed non-competitive with the drugs of the time, like Valium, and therefore never introduced into the United States. The Hoechst patents expired decades ago.