Clenbuterol is a steroid-like chemical that was initially developed to treat asthma in horses, working by relaxing the airways in the animals' lungs.
The drug is both a decongestant and a bronchodilator. A decongestant thins the blood to reduce blood pressure while a bronchodilator widens the vessels that carry oxygen, so the volume of oxygen in the blood increases.
In the U.S. in the past, clenbuterol has been used in animal rearing as well as by vets. In 1991, the U.S. Food Safety and Inspection Service found it had been fed to livestock, so the animals gained more muscle and less fat. But, again, in many countries, clenbuterol is illegal for animal use.
The drug is now controversial because of its use in bodybuilding and weight-loss programs.
In this article, we take a look at how clenbuterol works, when it is used, and what the risks are for people who take it.
Clenbuterol stimulates both the heart and central nervous system. It has a similar effect on the body as epinephrine and amphetamines.
It is also a beta-2-agonist, which is the opposite of a beta-blocker. While a beta-blocker will reduce the production of epinephrine and noradrenaline, clenbuterol increases it.
This increase will lead to a variety of effects, such as:
- rapid fat burning
- increased energy
- greater determination
Clenbuterol's initial use was as an asthma drug. However, bodybuilders, performance athletes, and those wanting to lose weight are now using the drug.
Clenbuterol can be used as a weight-loss aid because it can increase a person's metabolism. As well as reducing body fat and weight, it also allows the user to retain both muscle mass and body strength at the same time.
Clenbuterol became known as a celebrity diet secret because of its apparent use by celebrities and famous athletes.
One study reviewing data from two regional poison centers in the U.S. found that in 11 of the 13 reported cases of people taking clenbuterol, it had been used for weight loss reasons or as part of a bodybuilding regime.
The World Anti-Doping Agency have banned the use of clenbuterol at all times, both in and outside of competition.
Athletes and bodybuilders taking clenbuterol will often work on a program cycle that includes on and off periods.
Such a program could mean 2 days taking clenbuterol and 2 days without taking any, or perhaps a week taking the drug followed by a week of none.
Dosage can vary, depending on factors that include gender and tolerance, and it can be taken orally or injected.
Both methods have risks. Injections can cause scarring or air bubbles to form in the blood, while tablets can affect the liver.
When used in Europe and Latin America to open up the airways in cases of asthma, the recommended dose is 0.02–0.04 milligrams (mg) per day.
The reason clenbuterol is banned in so many countries and has become so controversial is that many side effects are associated with it.
Many of the side effects are the same as those associated with amphetamines, including:
Increased heart rate and dilation caused by the drug can lead to what is known as cardiac hypertrophy. This condition is when the heart grows to an abnormal size, which in turn can lead to a heart attack and eventually death.
Also, clenbuterol contains dopamine, which is commonly known as the reward hormone. Dopamine is closely associated with addiction. As such, clenbuterol can be highly addictive.
In many countries, clenbuterol is banned from being used in animals that will be consumed by humans.
In 1994, 140 people in Spain were hospitalized after eating meat tainted by clenbuterol. Similarly, in 2006, 336 people in China were poisoned after eating pork that contained it.
Athletes will often accompany the taking of clenbuterol alongside a diet that is high in protein, moderate in carbohydrates, and low in fat.
There has been an increase in the use of clenbuterol as a drug for bodybuilding and weight-loss purposes, with people obtaining it via the internet.
But due to the hidden dangers associated with clenbuterol, there can be serious risks for those who take it regularly.
The Department of Emergency Medicine in Newton, MA, reported two cases of people brought in for treatment because of clenbuterol use.
The men were bodybuilders, aged 18 and 22 years, and had heart palpitations, nausea, vomiting, and chest pain shortly after taking clenbuterol.
The Peking Union Medical College in Beijing, China, found that low doses of clenbuterol had minimal effects when tested on rabbits. However, medial doses had significant effects on the animals' heart rates, and higher doses could even lead to death.
The effects that clenbuterol can have on the heart and muscles will depend on how high a dose someone has been taking and for how long. The risks increase with the dose and duration.
Those taking high doses can experience long-term side effects quickly, such as a decrease in the size, weight, strength, and activity of the heart.
Clenbuterol is illegal for human consumption in the U.S. for a good reason, and anyone buying the drug online should be extremely cautious.
While some may choose to take the risk because of the less harmful side effects, they should always remember the potentially extreme side effects as well.