What is clenbuterol?

Clenbuterol is a potent, but banned, substance often used in the bodybuilding circles. It works by increasing the person’s metabolism, providing a strong fat burning effect. It also has an anabolic effect which can increase body’s muscle building and muscle preserving capabilities.

What is it used for?

Currently clenbuterol is legally prescribed in Australia by veterinarians as an airway dilator for horses. It is a relative of salbutamol, a drug used in ventolin puffers. Until the early 1990’s clenbuterol was also used to speed-up the development of livestock animals.

In 1992 there were 13 cases of clenbuterol poisoning in Catalonia, Spain where “Intoxication occurred in association with the ingestion of veal liver, irrespective of the way in which the liver had been cooked.” A 1995 research studying the poisoning went on to say “The findings reinforce the need to uphold the prohibition of the use of clenbuterol in cattle farming in those countries and communities where it already exists and to contemplate a stricter regulation of its therapeutic use.” (2)

Another study states, “Consumption of meat containing clenbuterol residues causes adverse health effects in humans, reduces the performance in exercise and disturbs reproductive system and hormone response.” (1)

Once the toxicity of metabolites (intermediate end product of metabolism) of clenbuterol was discovered, and the link how these metabolites can infect the food and cause food poisoning became clear, clenbuterol was banned in most developed countries.

What are the negative side-effects of clenbuterol?

Clenbuterol is a banned for human consumption in most developed countries because of its potential toxic effect on heart, especially on those with an underlying cardiovascular condition. The effects of clenbuterol are similar to adrenaline in the body and this can be fatal when combined with other substances, or when taken in too high doses.

A 2013 study reviewed clenbuterol exposures reported to two poison centers. Some of the negative clinical effects included: an abnormally rapid heart rate, widened pulse pressure, abnormally rapid breathing, deficiency of potassium in the bloodstream, an excess of glucose in the bloodstream, palpitations, chest pain, and tremor. (3)

In another study describing epidemiology and toxicity of clenbuterol in exposures reported to the NSW Poisons Information Centre, the researchers found that “at least 53 patients (84%) required hospitalisation. The commonest reasons for use were bodybuilding and slimming.” The cases also included one cardiac arrest in a 21-year-old man. (4)

Clenbuterol has also been shown to reduce the white blood cell count which can negatively affect the immune system.

When looking at the negative side effects it’s not surprising then that clenbuterol is prohibited by virtually every high level sporting agency. The negative side effects on athletes who take the drug over a long period of time are yet unknown, and any positive effects of taking clenbuterol seem to be temporary.


What is duromine?

Duromine is a prescription drug that is used for weight loss. The active ingredient phentermine is, according to Wikipedia, “a psychostimulant drug of the substituted amphetamine chemical class, with pharmacology similar to amphetamine. Phentermine stimulates the release of brain chemicals manipulating the mind to curb the appetite.”

It should be emphasized that Duromine is not a weight loss supplement, but a prescription drug.

What is it used for?

Phentermine is used medically as an appetite suppressant for short term use. Phentermine is usually prescribed for individuals who are morbidly obese. The drug on it’s own won’t lead to lasting weight loss results, but must be combined with a complete lifestyle change, including introduction of healthier diet and exercise habits.

What are the negative side-effects of Duromine/Phentermine?

Phentermine is classified as a Schedule IV drug meaning that “the abuse of the drug may lead to limited physical dependence or psychological dependence.” The United Nations International Narcotics Control Board (INCB) has warned phentermine users that it can be easily addicting. Phentermine has been banned in the United Kingdom since 2000 when the health officials discovered that the use could cause cardiovascular disease.

There are potentially severe side effects with the usage of phentermine. Cardiovascular effects such as palpitations, excessive heart rate and high blood pressure. Also some cases of stroke, angina, myocardial infarction, a cardiac failure and cardiac arrest have been reported.

Phentermine can also affect the central nervous system: overstimulation, restlessness, nervousness, insomnia, tremor, dizziness and headache have all been reported. As well as rare cases of euphoria followed by fatigue and depression.

Some of the gastrointestinal effects include nausea, vomiting, dry mouth, cramps, unpleasant taste, diarrhea, and constipation. Other adverse effects include trouble urinating, rash, impotence, changes in libido, and facial swelling. (5)


Two other website were also used for research: