About Clenbuterol® Does Clenbuterol build muscle?

A banned bronchodilator in the U.S. and by the Olympics, clenbuterol remains readily available through the Internet.

Clenbuterol first came to my attention through an e-mail question. The few claims I found of clenbuterol being an asthma medication seemed little more than a thinly veiled attempt to increase the acceptability of this banned drug.

Clenbuterol is a Beta-2 Agonist, this places it in the same classification as Albuterol and Terbutaline. Clenbuterol is associated with the same type of side effects as well; tremor, increased heart rate, nervousness, and cardiac arrhythmias in those with underlying heart disease. Those side effects seem to be significantly more pronounced than in medications now used for asthma today.

Banned in the U.S. for use in humans and animals, it’s still readily available through several Internet based suppliers. Primarily used in veterinary medicine, clenbuterol is becoming increasingly popular as a anabolic steroid substitute. Clenbuterol’s claim to fame is a supposed anabolic effect similar to anabolic steroids but to a much lesser effect and without steroid associated side effects.

Clenbuterol made itself known to the general public during the Barcelona Summer Olympics in 1992. Two athletes were banned from the games due to this drug. The Olympics isn’t the only place where clenbuterol is being used to cheat. Bodybuilders, weight trainers, and dieters are using it to build muscle and reduce body fat. Unfortunately, this drug is also making its way to teens as well due to its availability.

Another problem with clenbuterol is its use in animals, both show and livestock. Animals are given clenbuterol for reasons similar to those of athletes, to increase muscle mass and leanness. Unfortunately, clenbuterol and its metabolites end up in the muscles and organs. When eaten these animal products have cause illness in human with symptoms familiar to anyone that has used a rescue inhaler or nebulizer. There have been hundreds of documented clenbuterol poisonings in the U.S. and Europe due to eating contaminated meat. Symptoms such as muscle pain, shaking, rapid heart beat, and headache have been known to last as long as 6 days.

Clenbuterol is one of the most popular illegal drugs used in livestock in the United States today

Clenbuterol Toxicology and Scandals:

Clenbuterol is one of the most popular illegal drugs used in livestock in the United States today. It is a legal and also very popular drug in Europe and Canada for cattle and horses. The illegal use of powerful and potentially deadly drugs is endemic within the veal industry.
Clenbuterol is used to make confined calves and lambs gain muscle mass even though they get no exercise. Strong antibiotics are used to try to curb the chronic inflections and diarrhea that afflict calves and lambs who never go outside and may not even get colostrum from their mothers’ milk. Clenbuterol is also often illegally used as a fat partitioning agent to improve the aesthetic appearance of show animals.
The problem of clenbuterol is not just confined to animals. Livestock are usually fed a high amount of clenbuterol up until slaughter. While much of the clenbuterol will be excreted or metabolized, there is still a considerable amount retained by the animals especially in the liver, muscles, and retina.
Clenbuterol is a potent stimulant that is broken down in the liver. A recent article from Spain reports 113 cases of people who developed nervousness, rapid heart rate, muscle shaking, muscle pain and headache 15 minutes to 6 hours after eating veal liver (Public Health Reports, May-June 1995.) Their symptoms lasted from 90 minutes to 6 days. Interestingly, blood levels of clenbuterol were very low, while urine levels from the affected people were very high.
Clenbuterol has found popularity in bodybuilding and other sports where lean mass is desired. Athletes generally take a 20 mcg dose 3 times a day for 2 days then go off it for 2 days. They repeat this cycle for 6-8 weeks. The most prominant short term toxic effects athletes experience is heart palpatations, insomnia, and muscle cramping. The long term side effect would include destruction of the adrenergic receptors; permanant impairment of thyroid activity, making the athlete unable to regulate his/her metabolism and be intolerable to cold temperatures; death. The amount used by athletes are far less than what livestock are fed, and still less than the residual clenbuterol found in meat from animals that were fed clenbuterol.
A total of 1,074 samples taken in Great Britain in 1992 under the statutory and non-statutory surveillance programs were analyzed for residues of clenbuterol. These included 203 ox liver samples purchased from retail outlets. Only two of these retail samples were found to contain clenbuterol, at concentrations of 0.4 Вg/kg and 3.3 Вg/kg respectively. Neither of these residues would have likely posed any threat to human health. However, one of them was above the statutory maximum residue limit (MRL) of 0.5 Вg/kg, which applies to residues arising from licensed uses of clenbuterol. The results of this surveillance were given in response to a written Parliamentary Question on 2 March 1993.
In the light of these results, a further study of retail ox liver was undertaken. A total of 55 samples of ox liver were purchased from retail outlets throughout the UK in February and March 1993 (Table 1). No samples contained residues of clenbuterol, using an analytical method with a limit of determination of 0.2 Вg/kg.

TABLE 1: Surveillance for residues of clenbuterol in liver, February – March 1993

SpeciesDrugsMRL (Вg/kg)No. of samples analyzedNo. of sampleswith residues above MRL

Because of the continuing evidence of abuse of clenbuterol outside Great Britain, surveillance has been stepped up in 1993. A total of 2,264 samples of home-produced, imported and retail bovine tissues will be analyzed for clenbuterol under MAFF’s statutory and non-statutory surveillance schemes.
Clenbuterol is very hard to detect, until the recent development of a test that finds traces in a slaughtered animal’s retinas, the amount of clenbuterol residues in meat can be lethal to humans.
Clenbuterol is also very popular for show animals too. It was an all-American moment — grinning 16-year-old Ryan Rash resting his head on his grand champion steer Badger after winning the blue ribbon at the National Western Stock Show.
The lumbering, black steer fetched $37,500 at auction, and Ryan and his parents couldn’t be more proud. But within days, the ribbon had been stripped, the money forfeited and Ryan banned for life from the Denver show. The reason? Cheating. Badger had been illegally fed clenbuterol that beefed him up, giving him the straight lines and muscular physique of a champion.
Scott McEldowney, who admitted feeding clenbuterol to his 10-year-old daughter’s steer Barney, says he had to cheat to compete on a national level. “It’s like anything in life, either racing cars or anything,” said McEldowney, who has a small farm in Ansonia, Ohio, near Dayton. “If you’re going to play on the same level, let’s play on the same level.”
He and seven others at the Ohio State Fair were caught either drugging their animals with clenbuterol or injecting oil under their skin to give them a better appearance. His daughter, Jessica, was banned for life from showing at the state fair and had to return the $4,000 paid for her steer.
An Ohio Agriculture Department investigation led to the convictions of 10 people for either selling clenbuterol or tampering with livestock, and two Wisconsin veterinarians and one in Iowa have been indicted in the drug distribution scheme.
At the Tulsa State Fair in Oklahoma, six of the top animals tested positive for the drug. And in Louisville, Ky., clenbuterol was found last fall in the grand champion lamb at the North American International Livestock Expo.
The drug is most often smuggled in through Canada, where it is legally used to treat horse respiratory problems, FDA official George “Bert” Mitchell said. No human health problems have been reported domestically, however; only small amounts of drug residue have been detected in the eyeballs of the show animals.
McEldowney estimates 30 percent or more of exhibitors have used clenbuterol on their show animals. Barbara Wood, livestock director for the Tulsa State Fair that disqualified the six cheaters last year, puts the number at about 20 percent.
“At this time a year ago, I tried to deny we had a big problem, but I’ve changed my mind. It’s a serious problem,” said Eddie Smith, Oklahoma state supervisor of agricultural education and adviser to the Future Farmers of America. “I’m sure there’s always been a little fudging here and fudging there, but it’s definitely gotten a lot worse.


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