Fenfluramine,dextro 3D BS.png
Clinical data
ATC code
Legal status
Legal status
  • US: Unscheduled
  • Withdrawn from market
Pharmacokinetic data
Protein binding36%
Elimination half-life17–20 hours
  • (S)-N-Ethyl-1-[3-(trifluoromethyl)phenyl]-propan-2-amine
CAS Number
PubChem CID
Chemical and physical data
Molar mass231.262 g·mol−1
3D model (JSmol)
  • FC(F)(F)c1cccc(c1)C[C@@H](NCC)C
  • InChI=1S/C12H16F3N/c1-3-16-9(2)7-10-5-4-6-11(8-10)12(13,14)15/h4-6,8-9,16H,3,7H2,1-2H3/t9-/m0/s1 checkY

Dexfenfluramine, marketed as dexfenfluramine hydrochloride under the name Redux, is a serotonergic anorectic drug: it reduces appetite by increasing the amount of extracellular serotonin in the brain.[1] 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,[1] the FDA withdrew the approval in 1997.[2] 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 It was later superseded by sibutramine, which, although initially considered a safer alternative to both dexfenfluramine and fenfluramine[citation needed], was likewise removed from the US market in 2010.[3]

The drug was developed by Interneuron Pharmaceuticals, a company co-founded by Richard Wurtman, aimed at marketing discoveries by Massachusetts Institute of Technology scientists.[4] Interneuron licensed the patent to Wyeth-Ayerst Laboratories.[5] Although at the time of its release, some optimism prevailed that it might herald a new approach[citation needed], there remained some reservations amongst neurologists, twenty-two of whom petitioned the FDA to delay approval[citation needed]. Their concern was based on the work of George A. Ricaurte, whose techniques and conclusions were later questioned.[6]

See also


  1. ^ a b Fox SI (2011). Human Physiology (Twelfth ed.). McGraw Hill. p. 665.
  2. ^ FDA 15 September 1997. FDA Announces Withdrawal Fenfluramine and Dexfenfluramine (Fen-Phen)
  3. ^ "Abbott Pulls Diet Drug Meridia Off US Shelves". The Wall Street Journal. 8 October 2010. Archived from the original on 23 October 2010.
  4. ^ Lemonick MD, Dowell W, Nash JM, Ramirez A, Reid B, Ressner J (23 September 1996). "The New Miracle Drug?". Time. Archived from the original on 6 November 2010. Retrieved 3 October 2010.
  5. ^ Lemonick MD, Nash JM, Park A, Thompson D (29 September 1997). "The Mood Molecule". Time. Archived from the original on 3 October 2008. Retrieved 4 October 2010.
  6. ^ "DEA Accedes to Ecstasy Test". Wired. 2 March 2004.