Dexfenfluramine, formerly sold under the brand name Redux, is a serotonergic drug that was used as an appetite suppressant to promote weight loss.

Dexfenfluramine was, for some years in the mid-1990s, approved by the United States Food and Drug Administration (FDA) for the purposes of weight loss.

It was later superseded by sibutramine, which, although initially considered a safer alternative to both dexfenfluramine and fenfluramine,[5][6][7] was likewise removed from the US market in 2010.

[8][9] The drug was developed by Interneuron Pharmaceuticals, a company co-founded by Richard Wurtman, aimed at marketing discoveries by Massachusetts Institute of Technology scientists.

[11] Although at the time of its release, some optimism prevailed that it might herald a new approach,[12] there remained some reservations amongst neurologists, twenty-two of whom petitioned the FDA to delay approval.