Clen (Clenbuterol)

Clen and Fat Burning Supplements

Clenbuterol, marketed as Dilaterol, Spiropent, Ventipulmin.  Generically as clenbuterol, a sympathomimetic amine.  Used by sufferers of breathing disorders as a decongestant and bronchodilator. People with chronic breathing disorders such as asthma use this as a bronchodilator to make breathing easier. It is most commonly available as the hydrochloride salt, clenbuterol hydrochloride.


Effects and dosage

Clenbuterol is a β2 agonist with some structural and pharmacological similarities to epinephrine and salbutamol. While its effects more potent and longer-lasting as a stimulant and thermogenic drug. Causes an increase in aerobic capacity, central nervous system stimulation, blood pressure, and oxygen transportation. Increases the rate at which body fat is metabolized while increasing the body’s BMR. Commonly used for smooth muscle-relaxant properties as a bronchodilator and tocolytic.

Clenbuterol is also prescribed for treatment of horses, but equine use is usually the liquid form.

Human use

Clenbuterol, approved for use in some countries, free or via prescription. A bronchodilator for asthma patients.It can be dangerous if taken more than 0.12 mg.

Legal status

Clenbuterol hydrochloride is not an ingredient of any therapeutic drug approved by the US Food and Drug clenAdministration and is now banned for IOC-tested athletes. In the US, administration of clenbuterol to any animal used as food for human consumption is banned by the FDA. There are many fat burning supplements available that are safer, legal to use, and do not require a prescription to obtain.

Clenbuterol, a therapeutic drug for asthma, approved for human use in some countries in Europe (Bulgaria) and Asia (China).

Weight-loss drug

Although often used by bodybuilders in their “cut” periods, the drug more recently known to the mainstream, particularly through publicized stories of use by celebrities like Victoria Beckham, Britney Spears, and Lindsay Lohan. For its off-label uses a weight-loss drug similar to usage of other sympathomimetic amines like ephedrine, despite the lack of sufficient clinical testing either supporting or negating such use.

Notable cases of use as performance-enhancing drug

As a β2 sympathomimetic, clenbuterol used as a performance-enhancing drug.

A three-year suspension for taking clenbuterol kept sprinter Katrin Krabbe from competing in the 1992 Summer Olympics, and effectively ended her athletic career.

ClenbuterolIn 2006, San Francisco Giants pitcher Guillermo Mota, while a member of the New York Mets, received a 50-game suspension after testing positive for clenbuterol.In 2012, MLB officials announced they were again suspending Mota for 100 games due a positive test for clenbuterol.

American swimmer Jessica Hardy tested positive at the US trials in 2008. Subject to a one-year suspension, claiming she unknowingly took the drug in a contaminated food supplement.

Former New York Mets clubhouse employee Kirk Radomski admitted in his plea deal to distributing clenbuterol to dozens of current and former Major League Baseball players and associates.

After finishing fourth in the K-2 1000-m event at the 2008 Summer Olympics in Beijing, Polish sprint canoer Adam Seroczyńskiwas disqualified for taking this drug, and Chinese cyclist Li Fuyu tested positive for it at the Dwars door Vlaanderen race in Belgium on March 24, 2010.

In 2010, St. Louis Cardinals minor-league shortstop Lainer Bueno received a 50-game suspension for the 2011 season as a result of testing positive for clenbuterol.

Cyclist Alberto Contador of Spain banned for two years from professional cycling after testing positive for the drug at the 2010 Tour de France. He later stripped of the 2010 title of the Tour de France and the 2011 title of the Giro d’Italia.  CAS found that Contador probably tested positive due to a contaminated food supplement. 

Contador’s 2013 team-mate on the Team Saxo Bank squad, Mick Rogers. Tested positive for clen at the Japan Cup bike race. In April 2014 the Union Cycliste Internationale announced that it accepted Rogers’ explanation. The substance ingested by him after consuming contaminated meat whilst competing at the 2013 Tour of Beijing.  Upholding Rogers’ disqualification from the Japan Cup but declining to impose any further sanctions on him.

Players of the Mexico 2011 national football team found with clenbuterol in their bloodstreams. But acquitted by WADA after they claimed the clenbuterol came from contaminated food. FIFAalso claimed 109 players from the Under-17 World Cup in Mexico. They tested positive for this drug, because Mexican contaminated meat

In 2013, Mexican boxer Erik Morales, suspended for two years after testing positive for clenbuterol hydrochloride.

A complete list of athletes busted for the use of performance enhancing supplements can seen at

Side Effects of Clenbuterol

Clenbuterol may cause cardiac hypertrophy (enlargement of heart ventricles). A potentially serious form of heart damage, as well as irregular rhythms, and as stated above, specific cell death. Other side effects of clen use may include muscle tremors, increased perspiration, increased blood pressure, insomnia, headache, nausea and vomiting.

Athletes who are considering using clenbuterol need to seriously weigh the risks and benefits. Both the long-term and short-term side effects appear to be quite dangerous. Athletes using clen also need to be aware that they not assured of the safety. Also the purity or quality of the product they end up using. If your goals are to gain muscle and lose fat. Safer, legal ways to achieve that outcome, such as a well-designed nutrition and training routine. Also supplementing legal steroids is safe.