Chemically-enhanced fat loss: A closer look at clenbuterol

Everyone wants to see results from their training and diet plans. But not everyone has the dedication and commitment needed to stick to the plan. Others lack the patience to achieve their goals the healthy and natural way.

Women looking for a quick fat loss solution increasingly turn to regulated, prohibited or illegal substances, sometimes unknowingly because a partner, personal trainer or coach has recommended or offered it to them. After all, “everyone uses it”, right? 

While taking potentially dangerous and harmful illegal drugs, such as anabolic steroids, or pharmaceutical substances to add muscle and shed fat can be extremely effective, they come with serious risks.

Clenbuterol defined

Clenbuterol is one of those pharmaceutical substances developed for specific medical applications but is often used for its unintended benefits related to body conditioning.

Clen, as it is commonly known, is a steroid-like chemical (it is not an anabolic steroid, despite what many misinformed articles state) primarily used by vets as a bronchodilator to treat horses with chronic breathing disorders.

A bronchodilator relaxes smooth muscle in the lungs, which widens the airways (bronchioles) to make breathing easier.

Numerous countries around the world have also approved its use for treatment in humans (it remains banned in some countries like the US due to its many potential side effects).

Clen is most commonly taken as a tablet but it can also be injected. When prescribed to treat conditions like asthma in humans, it is usually administered in the form of Albuterol, Salbutamol or Ventolin, among other brand names or generics, via an inhaler.

Beyond its proven medical applications, clenbuterol is also a potent fat-loss agent and has muscle-sparing (anti-catabolic) benefits, which makes it appealing to bodybuilders and athletes. The World Anti-Doping Agency (WADA) has banned its use, both in and outside of competition, for these reasons.

The fat-loss factor

Let’s get the science stuff out of the way… Clen exerts its fat-loss effects via its influence on the adrenergic system. As a beta-2 adrenergic agent, clen stimulates beta-2 receptors to release adrenalin and noradrenalin. Beta-2 agonists also directly stimulate fat cells and increase fat loss.

What that means for fat loss….

These characteristics place clen in the same category as substances such as caffeine and ephedrine, which raise your metabolic rate through thermogenesis – a process that causes your body temperature to rise. The increase in temperature raises your body’s resting or basal metabolic rate (BMR).

This thermogenic effect amplifies the rate at which your body metabolises fat, even while at rest, and can make your training more effective at burning stored fat for energy. While this is a common characteristic of commercially available fat burners, clenbuterol is far more potent.

Muscle-sparing benefit

While there is a general lack of scientific evidence to support the claims, it is widely believed that clen helps to prevent muscle loss through beta-2 receptor stimulation in humans.

These claims stem from multiple animal studies, but human trials are rare, mainly because the substance is banned in key research markets like the US. The few that are available have been inconsistent in their findings.

Weighing up the risks

As with all stimulants and amphetamines, clen can cause anxiety, restlessness and insomnia. Excessive intakes by otherwise healthy individuals can also cause:

  • Shaking
  • Muscle tremors
  • Headaches
  • Abnormal sweating
  • Lowered blood potassium (hypokalemia)
  • Nausea and vomiting

The drug’s greatest risk stems from its impact on the cardiovascular system. Clen can cause heart palpitations, atrial fibrillation or an irregular and/or fast heartbeat. It can also increase blood pressure.

The increased stress on the heart can result in cardiac hypertrophy, a condition where the heart grows to an abnormal size and can, in turn, lead to a heart attack.

And clenbuterol stimulates the release of dopamine, a hormone closely associated with addiction.

Responsible use

Anyone with any underlying cardiovascular condition or a history of high blood pressure should avoid clen.

And while we do not recommend, condone not promote using banned or illegal substances, or scheduled drugs for anything other than medically-prescribed purposes, we always advocate for responsible use. 

Do not consider your significant other, coach or training partner as a responsible source of medical information. If you are considering using clen, seek medical advice and dosage guidelines from a qualified medical practitioner. It is essential to ensure you have a health screening prior to ensure you have no underlying medical conditions.  

Still considering it? Then make sure you’re monitoring your blood pressure. If your blood pressure breaches the stage 2 hypertension threshold of 140/90 mm Hg then cease use immediately.

It is also important to stop using any stimulant-based fat-loss or pre-workout products you may already take if you choose to try clen.

Is it worth it? 

Simply put – why risk your health for something you can achieve in a safe, natural way? No. The risks far outweigh the benefits. Gaining knowledge (and results) through putting in the effort and hard work, and achieving your goals without short cutting the process will result in not only a healthy body, but a strong and confident mind. 


Fitness magazine and its representatives do not condone nor promote the use of performance enhancing drugs and steroids. This information is provided solely for the purpose of fostering a better understanding of these substances through education, to ensure that if they are used, it is done so safely and responsibly.

Always get a full medical check-up and clearance before taking any stimulant-based product such as fat-loss or pre-workout supplement, especially if it is a potent scheduled substance like clenbuterol.


Author: Pedro van Gaalen

When he’s not writing about sport or health and fitness, Pedro is probably out training for his next marathon or ultra-marathon. He’s worked as a fitness professional and as a marketing and comms expert. He now combines his passions in his role as managing editor at Fitness magazine.

When he's not writing about sport or health and fitness, Pedro is probably out training for his next marathon or ultra-marathon. He's worked as a fitness professional and as a marketing and comms expert. He now combines his passions in his role as managing editor at Fitness magazine.

Leave a Reply

Your email address will not be published. Required fields are marked *