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An anorectic or anorexic is a drug which reduces appetite, resulting in lower food consumption, leading to weight loss.[1] These substances work by affecting the central nervous system or certain neurotransmitters to create a feeling of fullness or reduce the desire to eat. The understanding of anorexiant effects is crucial in the development of interventions for weight management, eating disorders, and related health concerns. The anorexiant effect can be induced through diverse mechanisms, ranging from hormonal regulation to neural signaling. Ghrelin, leptin, and peptide YY are among the hormones involved in appetite control. Additionally, neurotransmitters such as serotonin and dopamine in the central nervous system contribute significantly to the regulation of food intake.

By contrast, an appetite stimulant is referred to as orexigenic.

The term is (from the Greek ἀν- (an-) = "without" and ὄρεξις (órexis) = "appetite"), and such drugs are also known as anorexigenic, anorexiant, or appetite suppressant.


Used on a short-term basis clinically to treat obesity, some appetite suppressants are also available over-the-counter. Several appetite suppressants are based on a mix of natural ingredients, mostly using green tea as its basis, in combination with other plant extracts such as fucoxanthin, found naturally in seaweed. Drugs of this class are frequently stimulants of the phenethylamine family, related to amphetamine.[citation needed]

The German and Finnish[2] militaries issued amphetamines (Pervitin) to soldiers commonly during the Second World War.[3] Similarly, the UK military was supplied with more than 72 million Benzedrine tablets and the US military with an approximately equal amount for situations, in which fatigue was not deemed to be an acceptable option.[4] Following the war, large amphetamine surpluses were redirected for use on the black[5] and the civilian market. Indeed, amphetamine itself was sold commercially as an appetite suppressant until it was outlawed in most parts of the world in the late 1950s because of safety issues. Many amphetamines produce side effects, including addiction, tachycardia and hypertension,[6] making prolonged unsupervised use dangerous.

Public health concerns[edit]

Epidemics of fatal pulmonary hypertension and heart valve damage associated with pharmaceutical anorectic agents have led to the withdrawal of products from the market. This was the case with aminorex in the 1960s, and again in the 1990s with fenfluramine (see: Fen-phen).[7] Likewise, association of the related appetite suppressant phenylpropanolamine with hemorrhagic stroke led the Food and Drug Administration (FDA) to request its withdrawal from the market in the United States in 2000, and similar concerns regarding ephedrine resulted in an FDA ban on its inclusion in dietary supplements in 2004. A Federal judge later overturned this ban in 2005 during a challenge by supplement maker Nutraceuticals. It is also debatable as to whether the ephedrine ban had more to do with its use as a precursor in methamphetamine manufacture rather than health concerns with the ingredient as such.[citation needed]

Non-pharmacological alternatives[edit]

Weight loss effects of water have been subject to some scientific research as a potential non-pharmacological approach.[8] Drinking water prior to each meal may help in appetite suppression. Consumption of 500 mL (approximately 17 fl oz) of water 30 minutes before meals has been correlated with modest weight loss (1–2 kg; 2 to 4 lb) in obese men and women over a period of 8 to 12 weeks.[9][10]

Refeeding syndrome[edit]

Refeeding syndrome (RFS) is a metabolic disturbance which occurs as a result of reinstitution of nutrition in people and animals who are starved, severely malnourished, or metabolically stressed because of severe illness. When too much food or liquid nutrition supplement is eaten during the initial four to seven days following a malnutrition event, the production of glycogen, fat and protein in cells may cause low serum concentrations of potassium, magnesium and phosphate.[11][12] The electrolyte imbalance may cause neurologic, pulmonary, cardiac, neuromuscular, and hematologic symptoms—many of which, if severe enough, may result in death.

Refeeding syndrome can occur when someone does not eat for several days at a time usually beginning after 4–5 days with no food.[13]

Individuals with drug abuse who begin to reintroduce normal eating habits after a period of malnutrition may be at increased risk for refeeding syndrome.[14]

List of anorectics[edit]

Numerous pharmaceutical compounds are marketed as appetite suppressants.

The following drugs are listed as "centrally-acting antiobesity preparations" in the Anatomical Therapeutic Chemical Classification System:[15]

The following are listed as appetite depressants by MeSH, an index of medical journal articles and books.[17]

Other compounds with known appetite suppressant activity include:

See also[edit]


  1. ^ Lemke, Thomas L.; Williams, David A., eds. (2012). "Anorexiants as Pharmacologic Agents in the Management of Obesity". Foye's Medicinal Chemistry. Lippincott Williams & Wilkins. pp. 1451–6. ISBN 978-1-60913-345-0.
  2. ^ fi:Pervitiini
  3. ^ Ulrich, Andreas (May 6, 2005). "The Nazi Death Machine: Hitler's Drugged Soldiers". Spiegel Online. Retrieved 2011-01-05.
  4. ^ Bett, W. R. (1946-08-01). "Benzedrine Sulphate in Clinical Medicine". Postgraduate Medical Journal. 22 (250): 215. doi:10.1136/pgmj.22.250.205. ISSN 0032-5473. PMC 2478360. PMID 20997404.
  5. ^ Heal, David J; Smith, Sharon L; Gosden, Jane; Nutt, David J (June 2013). "Amphetamine, past and present – a pharmacological and clinical perspective". Journal of Psychopharmacology. 27 (6): 486. doi:10.1177/0269881113482532. ISSN 0269-8811. PMC 3666194. PMID 23539642.
  6. ^ Abenhaim, Lucien; Moride, Yola; Brenot, François; Rich, Stuart; Benichou, Jacques; Kurz, Xavier; Higenbottam, Tim; Oakley, Celia; Wouters, Emil; Aubier, Michel; Simonneau, Gérald; Bégaud, Bernard (1996). "Appetite-Suppressant Drugs and the Risk of Primary Pulmonary Hypertension". New England Journal of Medicine. 335 (9): 609–16. doi:10.1056/NEJM199608293350901. PMID 8692238.
  7. ^ Fishman, A. P. (1999). "Aminorex to Fen/Phen : An Epidemic Foretold". Circulation. 99 (1): 156–61. doi:10.1161/01.cir.99.1.156. PMID 9884392.
  8. ^ Handbook of Non Drug Intervention (HANDI) Project Team (2013). "Pre-meal water consumption for weight loss". Australian Family Physician. 42 (7): 478. PMID 23826600.
  9. ^ Dennis, Elizabeth A.; Dengo, Ana Laura; Comber, Dana L.; Flack, Kyle D.; Savla, Jyoti; Davy, Kevin P.; Davy, Brenda M. (2009). "Water Consumption Increases Weight Loss During a Hypocaloric Diet Intervention in Middle-aged and Older Adults". Obesity. 18 (2): 300–7. doi:10.1038/oby.2009.235. PMC 2859815. PMID 19661958.
  10. ^ Vij, Vinu Ashokkumar; Joshi, Anjalis (2014). "Effect of excessive water intake on body weight, body mass index, body fat, and appetite of overweight female participants". Journal of Natural Science, Biology and Medicine. 5 (2): 340–4. doi:10.4103/0976-9668.136180. PMC 4121911. PMID 25097411.
  11. ^ Mehanna HM, Moledina J, Travis J (June 2008). "Refeeding syndrome: what it is, and how to prevent and treat it". BMJ. 336 (7659): 1495–8. doi:10.1136/bmj.a301. PMC 2440847. PMID 18583681.
  12. ^ Doig, GS; Simpson, F; Heighes; Bellomo, R; Chesher, D; Caterson, ID; Reade, MC; Harrigan, PWJ (2015-12-01). "Restricted versus continued standard caloric intake during the management of refeeding syndrome in critically ill adults: a randomised, parallel-group, multicentre, single-blind controlled trial". The Lancet Respiratory Medicine. 3 (12): 943–952. doi:10.1016/S2213-2600(15)00418-X. ISSN 2213-2619. PMID 26597128.
  13. ^ Webb GJ, Smith K, Thursby-Pelham F, Smith T, Stroud MA, Da Silva AN (2011). "Complications of emergency refeeding in anorexia nervosa: case series and review". Acute Medicine. 10 (2): 69–76. doi:10.52964/AMJA.0470. PMID 22041604.
  14. ^ {{cite web}}: Missing or empty |title= (help)
  15. ^ ATC/DDD Index
  16. ^ "FDA requests the withdrawal of the weight-loss drug Belviq, Belviq XR (lorcaserin) from the market". Center for Drug Evaluation and Researcher. FDA. 2020-02-13.
  17. ^ MeSH list of agents 82001067
  18. ^ "European Medicines Agency recommends withdrawal of benfluorex from the market in European Union". European Medicines Agency. December 12, 2009. Retrieved August 22, 2022.
  19. ^ "Attention deficit hyperactivity disorder (ADHD) - Treatment". 2018-06-01. Retrieved 2021-09-20.
  20. ^ "Adderall Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing - WebMD". Retrieved 2021-09-20.
  21. ^ "Evekeo Prescribing Information" (PDF). Arbor Pharmaceuticals LLC. April 2014. pp. 1–2. Retrieved 9 January 2017.
  22. ^ Wood, Douglas M; Emmett-Oglesby, Michael W (1988). "Substitution and cross-tolerance profiles of anorectic drugs in rats trained to detect the discriminative stimulus properties of cocaine". Psychopharmacology. 95 (3): 364–8. doi:10.1007/BF00181948. PMID 3137623. S2CID 1105026.
  23. ^ Schubert, Matthew M.; Irwin, Christopher; Seay, Rebekah F.; Clarke, Holly E.; Allegro, Deanne; Desbrow, Ben (December 2017). "Caffeine, coffee, and appetite control: a review". International Journal of Food Sciences and Nutrition. 68 (8): 901–912. doi:10.1080/09637486.2017.1320537. hdl:10072/345209. ISSN 1465-3478. PMID 28446037.
  24. ^ Mohammadpour, Saba; Amini, Mohammad Reza; Shahinfar, Hossein; Tijani, Aliyu Jibril; Shahavandi, Mahshid; Ghorbaninejad, Parivash; Djafarian, Kurosh; Shab-Bidar, Sakineh (September 2020). "Effects of glucomannan supplementation on weight loss in overweight and obese adults: A systematic review and meta-analysis of randomized controlled trials". Obesity Medicine. 19: 100276. doi:10.1016/j.obmed.2020.100276. S2CID 225213522.
  25. ^ Guo, Liping; Yokoyama, Wallace; Chen, Maoshen; Zhong, Fang (November 2021). "Konjac glucomannan molecular and rheological properties that delay gastric emptying and improve the regulation of appetite". Food Hydrocolloids. 120: 106894. doi:10.1016/j.foodhyd.2021.106894. ISSN 0268-005X.
  26. ^ Klok, M. D.; Jakobsdottir, S.; Drent, M. L. (January 2007). "The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review". Obesity Reviews. 8 (1): 21–34. doi:10.1111/j.1467-789X.2006.00270.x. PMID 17212793. S2CID 24266123.
  27. ^ "FDA approves multiple generics of ADHD and BED treatment". Center for Drug Evaluation and Research. FDA. August 28, 2023.
  28. ^ "Desoxyn Prescribing Information" (PDF). United States Food and Drug Administration. December 2013. Retrieved 9 January 2017.
  29. ^ "Why smoking makes you lose weight and no, it's not a good idea". The Times of India. ISSN 0971-8257. Retrieved 2024-01-28.

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