Clenbuterol For Weight Loss: How It Works, Benefits, And Side Effects

Learn the truth behind this drug used for weight loss and how it works.

Medically reviewed by Melissa Hooper, MS, RDN Melissa Hooper Melissa Hooper MS, RDN facebook_icontwitter_iconlinkedin_iconyoutube_iconinsta_icon
Written by , MSc (Nutrition), CDE Priyanka Sadhukhan MSc (Nutrition), CDE Experience: 8 years
Edited by , BA (Literature & Psychology), PG Diploma Arshiya Syeda BA (Literature & Psychology), PG Diploma linkedin_icon Experience: 7 years
Fact-checked by , BSc (Life Sciences), Certified Health & Nutrition Life Coach Himanshi Mahajan BSc (Life Sciences), Certified Health & Nutrition Life Coach linkedin_icon Experience: 2 years

Desperation can sometimes lead to disasters! One such classic example is using clenbuterol for weight loss. A shocking fact is that many countries have not approved this pill to be used for weight loss (1). Despite this, its use is gaining traction among fitness freaks and bodybuilders for faster weight loss (2). So, does clenbuterol really help lose weight? If yes, what are the adverse effects that follow? Keep reading to know more.

What Is Clenbuterol?

Clenbuterol, popularly known as Clen, is a bronchodilatori  A drug that helps facilitate breathing by widening the bronchi or the airways and relaxing the muscles. and decongestant. It is a steroid-like substance, but not a steroid, and falls in the β2-agonist category. This drug causes the bronchial muscles to dilate (widen)and smoothen, thus opening up the airway. It is usually taken to prevent asthma attacks (3). It stimulates the beta-2 adrenergic receptors and has anti-catabolici  Substances that help decrease the breakdown of proteins and muscle mass in the body as well as provide energy. and thermogenic effectsi  The process of heat production in the body that helps perform vital functions, such as digestion, absorption, and storage of food. . Clenbuterol is available in the market as clenbuterol hydrochloride (4). 

How Does Clenbuterol Aid Weight Loss? Is it Safe?

Clenbuterol is a thermogenic stimulant. Thermogenic chemicals are thought to increase the body’s metabolic rate and BMR. Increased energy and BMR make you lose weight (4). A study conducted on horses concluded that the administration of clenbuterol (0.8𝜇/kg) helps in body fat burning with no significant effect on body weight (5). Anecdotal evidence suggests that it may aid muscle preservation. Other studies conducted on horses and mice have found that long-term use of clenbuterol increases the gene expression of muscle components and lipid metabolizing enzymesi  Proteins that help speed up chemical reactions in our body and play a crucial role in digestion, liver function, etc. , which causes lipolysis (fat breakdown) (6), (7), (8). So, it can be concluded that clenbuterol stimulates skeletal muscle growth, boosts metabolism, and aids in weight loss.

In a study conducted on mice, the clenbuterol treatment of lean male and female wild-type mice showed significant improvement in glucose intolerance. Check out the graph below to learn the difference between the glucose tolerance level of mice treated with regular drinking water and clenbuterol-containing water.

Chronic Clenbuterol Administration Improves Glucose Tolerance In Mice

Source: Clenbuterol exerts antidiabetic activity through metabolic reprogramming of skeletal muscle cells

Very limited studies have been done on humans to prove the weight-loss effects of clenbuterol, which is why it is banned by the FDA for human consumption. It is not safe to consume clenbuterol for weight loss without consulting a doctor as its usage is very restricted.

Clenbuterol Dosage For Weight Loss

Woman taking dosage of clenbuterol for weight loss
Image: Shutterstock

The recommended dosage of clenbuterol for the treatment of bronchial asthma is 20-30 µg, twice daily. Bodybuilding and athletic performance may improve with this drug. However, according to the Drug Enforcement Administration, bodybuilders and athletes abuse this drug by taking 60-120 µg per day along with other performance-enhancing drugs (9).

Bodybuilders, celebrities, models, athletes, and dieters take clenbuterol in “cutting cycles.” The continuous intake of this drug leads the body to build a tolerance to it, making the beta-2 adrenoreceptors become less sensitive to it. Hence, it is usually taken in the following cycles:

  • Two weeks on – Two weeks off
  • Two days on – Two days off

A blogger shares his personal experience of using Clenbuterol and how it showed positive results in weight loss. On his blog SkinnyAbbey, he writes, “By the fifth week of my off cycle, I had shed a lot of adipose fat in my body…so as to fully ascertain this, (I) had to take my weight measurement and for real it had dropped from 185 lbs to 155 lbs. Thanks to Clenbuterol fat burner (i).”

You must be wondering how much weight one can possibly lose with the help of clenbuterol. Check out the answer below. 

Apart from weight loss, some individuals also seem to be keen about using Clenbuterol for bodybuilding. But how safe is it? Learn more in the next section.

Clenbuterol For Bodybuilding

Clenbuterol contains thermogenic properties that may lead to an increased calorie burn. It may also enhance cardiovascular efficiency and stamina. While some bodybuilders have used it for muscle growth and fat loss, the FDA has not not approved it for human use (10). It is essential to prioritize safer, legal methods to aid bodybuilding workouts over Clenbuterol as it may cause serious side effects like heart palpitations, anxiety, and other long-term health risks (11). Always consult a physician before considering Clenbuterol for bodybuilding.

Best Time To Take Clenbuterol

Clenbuterol can ideally be taken in the morning, as it minimizes potential sleep disturbances caused by its stimulant effects. However, use it only under medical supervision. Self-administration can lead to harmful side effects and is illegal in many places.

Are you also wondering how much weight one can possibly lose with Clenbuterol? Check out the answer below.

How Much Weight Loss Is Expected Of Clenbuterol?

Woman experiencing weight loss because of clenbuterol
Image: Shutterstock

It depends on the approach and the level of lifestyle changes one makes in their daily life. It is reported that following the above dosage, eating healthy, working out, and getting proper rest results in 3-4 pounds weight loss per week. However, clenbuterol is still not recommended for weight loss as it has many dangerous side effects. Check them out in the next section.

Clenbuterol Side Effects

Woman experiencing nausea as a side-effect of clenbuterol
Image: Shutterstock
  • A case study has reported that the ingestion of 20 𝜇g of clenbuterol (which is the lowest reported dose of clenbuterol exposure leading to toxicity) results in tachycardia (rapid heartbeat), electrolyte imbalance, nausea, vomiting, anxiety, and increased blood pressure (10).
  • Once you get used to seeing yourself fit and active, you can get addicted. And once you stop using the drug, you may experience withdrawal symptoms and stress.
  • Clenbuterol may cause a decrease in the body’s taurine and potassium stores, which can result in muscle cramping.
  • You may also experience headaches, shaking hands, and excessive appetite.
protip_icon Did You Know?
In December 2006, over 300 people suffered from food poisoning due to pork contaminated by clenbuterol.

The Best Thing About Clenbuterol

Most weight loss pills and diets lead to loss of lean muscle mass. But, that is not the case with clenbuterol. Clenbuterol is catabolic, which means it breaks down fat, but it is also anabolic, meaning it prevents the loss of muscle but stimulates the growth of skeletal mass (7), (8). As you build muscle and skeletal mass, your weight on the scale may not show much difference, but you will see a leaner and toned body. This is because muscle is denser than fat, so 1lb muscle looks leaner than 1lb fat. This is why Clenbuterol is so popular amongst bodybuilders.

Here is a list of popular trade names of clenbuterol.

Clenbuterol Trade Names

  • Clenbuterol
  • Clenabol
  • Clenbutaroll
  • Ventipulmin
  • Sopharma Clen
  • Spiropent
  • Clenbuterol Hydrochloride

But the biggest question is, can you take clenbuterol for weight loss? Here’s what you should know.

Can You Take Clenbuterol For Weight Loss?

If you are 10-15 lbs overweight, you can take clenbuterol under the guidance of a medical professional. It acts the best when you are in good shape and want to get in better shape. But if you are very obese and need to lose a lot of weight, clenbuterol is not for you. Your weight loss should be initiated under the supervision of an experienced professional with proper nutrition, exercise, and supplements. After you lose a good amount of fat, you may use clenbuterol to get rid of the last bit of fat and build muscle mass.

Is Clenbuterol Safe For Weight Loss?

Woman consulting doctor before taking clenbuterol for weight loss
Image: Shutterstock

Always consult your doctor before using clenbuterol for weight loss. Like other drugs, it may not be safe if you overuse or misuse it. If your doctor does not give you the clearance to use clenbuterol, you should simply not use it. Avoid it if you are suffering from heart disease, anxiety, and hypertensioni  A condition in which blood pressure spikes above the normal range and can lead to a heart attack or stroke. . It can also pose serious health risks if you overdose yourself to lose weight quickly.

When taken in proper dosages under the guidance of a professional, you can reap the many benefits of clenbuterol. Here is the list of benefits of taking clenbuterol to lose weight.

Benefits Of Clenbuterol For Weight Loss

Clenbuterol increases muscle mass
Image: Shutterstock
  • Clenbuterol increases muscle mass and lean fat mass. Being an anabolic drug, it increases skeletal muscle growth but decreases exercise duration and endurance (8), (11).
  • When given to heart-operated rats, clenbuterol alone or in combination with mechanical unloading was found to improve heart function (12).
  • The drug is usually taken with vitamins and other energy supplements, thus reducing the need for a very strict diet regimen. Though food is important even when you are subjecting yourself to such physically challenging activity, you can, at times, steal a day for yourself. Appetite suppression is not required.
protip_icon Trivia
Celebrities like Victoria Beckham, Nicole Richie, Lindsay Lohan, and Britney Spears have used clenbuterol to lose weight.

Is Clenbuterol Banned In A Few Countries?

Yes, Clenbuterol is banned in countries like the USA, Australia, UK, New Zealand, Canada, and many other countries. In these countries, you cannot buy clenbuterol as a supplement or weight-loss pill, but it is used for veterinary purposes. Outside the USA, it is available by prescription for the treatment of asthma (9). Clenbuterol was banned because some people had overdosed themselves and seriously damaged their health. Since the doctors could not control the overuse of this drug, it was finally banned. However, it is still legal in countries like China, India, Bulgaria, and Mexico.

Infographic: Is Clenbuterol Safe For Weight Loss?

Clenbuterol, a steroid-like drug, dilates the bronchial muscles and acts like a decongestant. It is used to avoid asthma attacks. It also has thermogenic properties and increases the body’s metabolism to potentially help with weight loss. However, is clenbuterol safe for weight loss? In the following infographic, we have listed its benefits and side effects you need to be aware of. Take a look.

is clenbuterol safe for weight loss (infographic)

Illustration: StyleCraze Design Team

Clenbuterol stimulates thermogenesis which increases your BMR and energy to make you lose weight. It also improves skeletal muscle growth and boosts metabolism. Although it is a hit among fitness freaks, the FDA has banned this stimulant as there are not enough human studies to back it up. The recommended dosage is about 0.02-0.03 mg. However, this stimulant may cause side effects like addiction, headache, nausea, and a decrease in taurine and potassium levels in the body. If you would like to try clenbuterol for weight loss, you should consult a doctor to get the correct dosage for your body.

Frequently Asked Questions

Can you take clenbuterol without exercise?

No, it is not advisable to take clenbuterol without exercising. It may slow down metabolism and lead to weight gain.

Can clenbuterol cause a stroke?

Yes, clenbuterol may increase the risk of stroke if taken in excess. Hence, caution is advised.

Does clenbuterol affect your hormones?

No, clenbuterol may not affect the hormones. However, there is no quality research in this regard.

Is clenbuterol good for cardio?

Clenbuterol may improve stamina and is taken during cardio. But it may increase heart rate and palpitations and may negatively affect heart health. Hence, caution is advised.

How long do the effects of clenbuterol last?

The effects of clenbuterol last for 5- 8 hours.

Key Takeaways

  • Clenbuterol is a steroid-like compound primarily used for treating asthma attacks.
  • It has thermogenic properties which help boost metabolism and promote fat loss.
  • Maintain caution when using clenbuterol as it can cause various side effects like rapid heart rate, sweating, insomnia, and muscle cramps.
  • Multiple countries have banned this medicine due to its damaging impact on users, leading them to overdose on the medication.


Articles on StyleCraze are backed by verified information from peer-reviewed and academic research papers, reputed organizations, research institutions, and medical associations to ensure accuracy and relevance. Read our editorial policy to learn more.

  1. Clenbuterol: a substitute for anabolic steroids? Medicine and Science in Sports and Exercise, U.S. National Library of Medicine, National Institutes of Health.
  2. A descriptive study of adverse events from clenbuterol misuse and abuse for weight loss and bodybuilding, Substance Abuse, U.S. National Library of Medicine, National Institutes of Health.
  3. Clenbuterol, U.S. National Library of Medicine, National Center for Biotechnology Information, National Institutes of Health.
  4. Clenbuterol Human Effects, RUcore, Rutgers University Libraries
  5. Effect of long-term oral administration of a low dosage of clenbuterol on body fat percentage in working and nonworking adult horses, American Journal of Veterinary Research, U.S. National Library of Medicine, National Institutes of Health.
  6. Differential expression of skeletal muscle genes following administration of clenbuterol to exercised horses, BMC Genetics, U.S. National Library of Medicine, National Institutes of Health.
  7. Effect of clenbuterol on apoptosis, adipogenesis, and lipolysis in adipocytes, Journal of Physiology and Biochemistry, U.S. National Library of Medicine, National Institutes of Health.
  8. Anabolic effects of clenbuterol on skeletal muscle are mediated by beta 2-adrenoceptor activation, The American Journal of Physiology, U.S. National Library of Medicine, National Institutes of Health.
  9. Clenbuterol, Drug Enforcement Administration, Diversion Control Division, Drug & Chemical Evaluation Section.
  10. Low Dose Clenbuterol Toxicity: Case Report and Review of Literature
  11. Case of low dose clenbuterol toxicity, BMJ Case Reports, U.S. National Library of Medicine, National Institutes of Health.
  12. Clenbuterol increases lean muscle mass but not endurance in patients with chronic heart failure, The Journal of Heart and Lung Transplantation, U.S. National Library of Medicine, National Institutes of Health.
  13. Role and possible mechanisms of clenbuterol in enhancing reverse remodeling during mechanical unloading in murine heart failure, Cardiovascular Research, U.S. National Library of Medicine, National Institutes of Health.
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Melissa Hooper

Melissa Hooper MS, RDN

Melissa Hooper is an award-winning registered dietitian/nutritionist with over 20 years of experience in a variety of industries. She is passionate about and committed to helping people improve quality of life through nutrition and healthy lifestyle behaviors. Her background includes clinical nutrition in cardiac, renal, weight management, and nutrition-related disease management. She is an expert in patient education, program development, and media/marketing full bio

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