Dexfenfluramine, marketed as dexfenfluramine hydrochloride under the name Redux, is a serotonergicanorectic drug: it reduces appetite by increasing the amount of extracellular serotonin in the brain. It is the d-enantiomer of fenfluramine and is structurally similar to amphetamine, but lacks any psychologically stimulating effects.
Dexfenfluramine was, for some years in the mid-1990s, approved by the United States Food and Drug Administration for the purposes of weight loss. However, following multiple concerns about the cardiovascular side-effects of the drug, the FDA withdrew the approval in 1997. After it was removed in the US, dexfenfluramine was also pulled out in other global markets. It was later superseded by sibutramine, which, although initially considered a safer alternative to both dexfenfluramine and fenfluramine, was likewise removed from the US market in 2010.