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Systematic (IUPAC) name
CAS number 37148-27-9
ATC code R03AC14 R03CC13
PubChem 2783
Chemical data
Formula C12H18Cl2N2O 
Mol. mass 277.19
Pharmacokinetic data
Bioavailability 89-98% orally
Metabolism  ?
Half life 36-39 hours
Excretion  ?
Therapeutic considerations
Pregnancy cat.


Legal status


Routes oral

Clenbuterol is a drug prescribed to sufferers of breathing disorders as a decongestant and bronchodilator. People with chronic breathing disorders like asthma use this as a bronchodilator to make breathing easier. It is most commonly available in salt form as Clenbuterol hydrochloride.


Effects and Dosage

Clenbuterol is a β2 adrenergic agonist with some similarities to ephedrine, but its effects are more potent and longer-lasting as a stimulant and thermogenic drug. It causes an increase in aerobic capacity, CNS stimulation, and an increase in blood pressure and oxygen transportation. It increases the rate at which fat and protein is used up in the body at the same time as slowing down the storage of glycogen. It is commonly used for smooth muscle relaxant properties. This means that it is a bronchodilator and tocolytic. It is usually used in dosages anywhere from 20-60 micrograms a day when prescribed. A dose of about 150 μg should never be exceeded in a day. It is also prescribed for treatment of horses, however, equestrian usage is usually the liquid form of clenbuterol.

Human use

Recently clenbuterol has been touted as a weight loss drug and in some countries is prescribed as a bronchodilator for asthma patients. The same doctor who prescribed 800 kids adderall to lose weight and created The Unconventional Diets System has made claims that clenbuterol is actually healthy. Human use can lead to side-effects. With many major diet review websites talking about clenbuterol and accessible via the internet, the drug is being used as a mainstream dietary supplement.

Veterinary use

Clenbuterol is used worldwide for the treatment of allergic respiratory disease in horses, as it is a bronchodilator. A common trade name is Ventipulmin. It can be used both orally and intravenously. It is also a non-steroidal anabolic and metabolism accelerator, through a mechanism not well understood. Its ability to induce weight gain and a greater proportion of muscle to fat makes its illegal use in livestock popular.

Food contamination

In September 2006 over 330 people in Shanghai were reported to have been poisoned by eating pork contaminated by Clenbuterol that had been fed to the animals to keep their meat lean.[1]

Legal status

As of fall, 2006, Clenbuterol is not an ingredient of any therapeutic drug approved by the U.S. Food and Drug Administration, but is still used as an unproven slimming aid,[2] and is now banned for IOC-tested athletes.[3] Jason Grimsley, former Major League baseball pitcher, admitted to using this drug. Former Major League Baseball first Baseman David Segui has admitted to ordering the substance. Female singer, Britney Spears, has been reported as being a user of the drug in order to boost rapid weight loss, according to reports from the newspaper, The Sun, and has been doing so for over half a year. The tennis player Mariano Puerta was once penalized for use of clenbuterol. Australian wrestler Mitchil Mann was also suspended for testing positive for the drug.[4]


  1. ^ "Pigs fed on bodybuilder steroids cause food poisoning in Shanghai", AFP, 2006-09-19. Retrieved on 2006-09-19. (English) 
  2. ^ Howard, Rebecca. "The size zero pill", Daily Mail, 2006-10-09. Retrieved on 2007-07-01. 
  3. ^ Guest, Katy. "Clenbuterol: The new weight-loss wonder drug gripping Planet Zero", The Independent, 2007-04-10. Retrieved on 2007-04-10. 
  4. ^ "Drugs investigation nets fourth victim", Australian Associated Press, The Age, 2007-03-14. Retrieved on 2007-04-10. 

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Clenbuterol". A list of authors is available in Wikipedia.
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