Clinical data
Trade namesDidrex, Recede
Other namesN-benzyl-N-methylamphetamine
AHFS/Drugs.comProfessional Drug Facts
License data
Routes of
By mouth
ATC code
  • None
Legal status
Legal status
Pharmacokinetic data
Protein binding75–99%
Elimination half-life4-6 hours
  • (2S)-N-Benzyl-N-methyl-1-phenylpropan-2-amine
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass239.362 g·mol−1
3D model (JSmol)
  • N(C)(Cc1ccccc1)[C@@H](C)Cc2ccccc2
  • InChI=1S/C17H21N/c1-15(13-16-9-5-3-6-10-16)18(2)14-17-11-7-4-8-12-17/h3-12,15H,13-14H2,1-2H3/t15-/m0/s1 checkY
 ☒NcheckY (what is this?)  (verify)

Benzphetamine (brand name Didrex) is a substituted amphetamine used short-term along with a doctor-approved, reduced-calorie diet, exercise, and behavioral program for weight loss. It is prescribed for obesity to people who have been unable to lose weight through exercise and dieting alone. It is a prodrug to dextroamphetamine and dextromethamphetamine.[3][4][5]

Benzphetamine is an anorectic, primarily promoting weight loss through reduced appetite. It also slightly increases metabolism.


Benzphetamine is a sympathomimetic amine and is classified as an anorectic.[6] The drug's main function is to reduce appetite, which in turn reduces caloric intake.[medical citation needed]

Although the mechanism of action of the sympathomimetic appetite suppressants in the treatment of obesity is not fully known, these medications have pharmacological effects similar to those of amphetamines. Amphetamine and related sympathomimetic medications (such as benzphetamine) are thought to stimulate the release of norepinephrine and/or dopamine from storage sites in nerve terminals of the lateral hypothalamic feeding center, thereby producing a decrease in appetite. This release is mediated through the binding of benzphetamine to VMAT2 and inhibiting its function, causing a release of these neurotransmitters into the synaptic cleft through their reuptake transporters. Tachyphylaxis and tolerance have been demonstrated with all drugs of this class.[medical citation needed]

Benzphetamine has a half-life of 4–6 hours.[7]


Benzphetamine is contraindicated in patients with advanced arteriosclerosis, symptomatic cardiovascular disease, moderate to severe hypertension, hyper-thyroidism, known hypersensitivity or idiosyncrasy to sympathomimetic amines, and glaucoma, or who have recently used a MAOI. Benzphetamine should not be given to patients who are in an agitated state or who have a history of drug abuse.[8]

Controlled substance classification

Benzphetamine is unique in its classification as a Schedule III drug in the United States. (Most members of the amphetamine family are classified in the more highly regulated Schedule II.) Benzphetamine is metabolized by the human body into amphetamine and methamphetamine, making it one of a number of drugs to undergo in vivo conversion to a substance of higher addiction and abuse potential.[9]


  1. ^ "Benzphetamine". Toxnet. Archived from the original on 2018-11-01.
  2. ^ Anvisa (2023-07-24). "RDC Nº 804 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 804 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-07-25). Archived from the original on 2023-08-27. Retrieved 2023-08-27.
  3. ^ AHC Media, LLC (17 March 2014). Pediatric Trauma Care II: A clinical reference for physicians and nurses caring for the acutely injured child. AHC Media, LLC. pp. 118–. ISBN 978-1-934863-59-6.
  4. ^ Cody JT, Valtier S (1998). "Detection of amphetamine and methamphetamine following administration of benzphetamine". Journal of Analytical Toxicology. 22 (4): 299–309. doi:10.1093/jat/22.4.299. PMID 9681333.
  5. ^ Budd RD, Jain NC (1978). "Short Communication: Metabolism and Excretion of Benzphetamine: Sources of Error in Reporting Results". Journal of Analytical Toxicology. 2 (6): 241. doi:10.1093/jat/2.6.241.
  6. ^ Valentine JL, Middleton R (April 2000). "GC-MS identification of sympathomimetic amine drugs in urine: rapid methodology applicable for emergency clinical toxicology". Journal of Analytical Toxicology. 24 (3): 211–222. doi:10.1093/jat/24.3.211. PMID 10774541.
  7. ^ Woo T (2015-08-03). Pharmacotherapeutics for Advanced Practice Nurse Prescribers, 4th Edition. F.A. Davis Company. p. 226. ISBN 978-0-8036-3827-3.
  8. ^ "Benzphetamine". Toxnet. Archived from the original on 2018-11-01.
  9. ^ Musshoff F (February 2000). "Illegal or legitimate use? Precursor compounds to amphetamine and methamphetamine". Drug Metabolism Reviews. 32 (1): 15–44. doi:10.1081/DMR-100100562. PMID 10711406. S2CID 20012024.