Clenbuterol Hydrochloride Usage, Ultimate Results, Side Effects (2021)

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Written By Jonathan Deventer

Clenbuterol Hydrochloride

clenbuterol hcl

Clenbuterol hydrochloride, also known as simply Clenbuterol, Clenbuterol HCl, or Spiropent, is a drug component that expands bronchus or bronchial tubes in the lungs, often used in the treatment of asthma, COPD, and other lung disorders.

It’s an adrenergic beta-agonist, implying that it specifically binds to and activates beta-adrenergic receptors.

Before using Clenbuterol hydrochloride for weight loss, be aware of its true purpose, usage, and possible side effects. Click here to visit our recommended supplier.

A sympathomimetic amine, Clenbuterol is neither an anabolic steroid nor a fat burning drug.

How Clenbuterol Hydrochloride Works

Athletes and bodybuilders often use Clenbuterol for weight loss, with varying results. It can protect lean muscle gains and give you an intense surge of energy for intense workouts.

Sympathomimetic amines, often known as simply sympathomimetic, are compounds that stimulate certain functions of the sympathetic nervous system.

Clenbuterol is meant as an anti-asthmatic, not a weight-loss drug or to mimic the effects of an anabolic steroid.

It’s a bronchodilator whose main mechanism of action is that of a sympathomimetic with a predominant beta-adrenergic activity that influences specific actions on beta-2 receptors.

The sympathetic nervous system is a branch of the central nervous system responsible for autonomic functions in the body.

The sympathetic nervous system is most known for the “fight or flight” response to fear resulting in an increased heartbeat, increased blood pressure, sweating, and dilation of pupils.

Clenbuterol hydrochloride, when used for the purpose in which it was designed (to relax smooth muscular tissues of the bronchi and bronchial tubes in the lungs.

Such as during an asthma attack or in conditions such as COPD), is an effective treatment, but as with many drugs on the market, today is often misused for other reasons.

Bodybuilders and athletes take advantage of the potential for Clenbuterol to act as a fat-burning agent that also has properties that can build and preserve muscle tissue.

In the past, Clenbuterol was used on cattle to increase the production of lean muscle mass.

Today, Clenbuterol is misused not only by bodybuilders and athletes but by men and women seeking fast weight loss due to its relatively long stimulatory effect on the body.

Some scientific research has noted that Clenbuterol hydrochloride is effective in reducing fat mass, and it does have some potential to increase the synthesis of proteins required for muscle and tissue growth.

However, studies have also shown that such effects are temporary in nature.

Clenbuterol Hydrochloride Side Effects


It should be noted that numerous studies found in journal articles apply to animals such as horses and rats.

The potential for damaging side effects in humans and animals has also been noted. As an example, “A descriptive study of adverse events from Clenbuterol misuse and abuse for weight loss and bodybuilding.(2013)

The potential for other damaging side effects as well as toxicity have been reported around the world when the drug is used for bodybuilding or weight loss: “Clenbuterol toxicity: an NSW poisons information center experience.(2014)

Clenbuterol can produce a number of adverse reactions such as skeletal muscle tremors, heart palpitations, increased heart rate (tachycardia), anxiety, headaches, and others.

Clenbuterol hydrochloride does interact with other drugs including loop diuretics and drugs such as thiazide, high-dose theophylline, and corticosteroids.

Clenbuterol Hydrochloride For Weight Loss?


Among bodybuilding circles, Clenbuterol lacks the reputation of promoting significant weight loss, and in most cases is only used by individuals with a few pounds to lose prior to a competition.

Clenbuterol has not shown significant ability in regard to weight loss for individuals who are overweight or obese.

In addition, no drug can act on its own to increase weight loss or long-term weight loss management. Diet and exercise are more effective approaches.

So while Clenbuterol is considered a relatively potent beta-adrenergic receptor agonist, and it does influence those receptors (and in turn influences fat-burning capabilities), high doses of Clenbuterol would be required to provide significant benefits.

Such higher doses also naturally increase the potential for side effects and toxicity.

Consumers will find a variety of websites that promote the use of Clenbuterol for weight loss, and many of them claim that it can be done safely.

However, an equal number of articles warn against the potential dangers of using Clenbuterol or other drugs for reasons other than which they were designed, and in this case, mainly as an asthma treatment in horses.

Some users claim that Clenbuterol messes up their metabolism, contributes to eating disorders, and/or abruptly stops working.

A person may experience a rebound effect after losing weight and discontinued use of Clenbuterol, and then gain that initial weight back, and sometimes more.

Before considering Clenbuterol hydrochloride for weight loss or for muscle building, be aware of the potential dangers of relying on a drug to do all the work for you.

Diet, exercise, a healthy lifestyle, and genetics play a role in body fat to lean muscle ratios.

Clenbuterol hydrochloride is an effective drug when used as it is intended, but can be dangerous for those wishing to lose weight or to increase muscle mass.



  1. Groot MJ. Possible contamination with clenbuterol from treated veal calves to untreated pen mates. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2013.
  2. Miao P. Melamine functionalized silver nanoparticles as the probe for electrochemical sensing of clenbuterol. ACS Appl Mater Interfaces. 2014 Jun 11.
  3. McCormick C. Clenbuterol and formoterol decrease force production in isolated intact mouse skeletal muscle fiber bundles through a beta2-adrenoceptor-independent mechanism. J Appl Physiol (1985). 2010 Dec.
  4. Cudmore LA. Effects of oral clenbuterol on the clinical and inflammatory response to endotoxaemia in the horse. Res Vet Sci. 2013 Jun.
  5. Vulić A. Comparison of clenbuterol and salbutamol accumulation in the liver of two different mouse strains. J Anal Toxicol. 2014 Jun.
  6. Zhang Q. Beta(2)-adrenoceptor agonist clenbuterol reduces infarct size and myocardial apoptosis after myocardial ischaemia/reperfusion in anaesthetized rats. Br J Pharmacol. 2010 Jul.

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