Clenbuterol – An In-Depth Look At The Controversial Drug

Clenbuterol has been one of the most popular steroids in the bodybuilding circuit for many years now.

Originally, it was designed to treat asthma in horses.

Bodybuilders, actors, and amateurs have used it to burn fat and build lean muscle for years.

Its ability to get users shredded quickly has made it very popular.

When compared to other fat burners, this chemical takes thermogenesis to a whole new level.


Unfortunately, there happens to be a lot of conflicting information on this steroid online.

So I decided to compile all the information I could find on Clenbuterol in one place.


What Is Clenbuterol?

Clenbuterol Hydrochloride, Clenbuterol, Bute, or Clen is technically not a steroid, just a steroid-like chemical.

It can be better classified as a stimulant drug.

The group of drugs that it is a part of is called beta-2-agonists.

Beta-2-agonists, β2 (beta2) adrenergic receptor agonists are a group of drugs that stimulate the β2 adrenergic receptors.

They dilate bronchial passages, cause vasodilation, and help release insulin. These drugs are most commonly used against COPD, asthma, and other pulmonary disorders.

This group of drugs can be sectioned into short-acting, long-acting, as well as ultra-long-acting agonists.

Here, clen is considered to be a long-acting beta2 adrenergic receptor agonist.

This was originally designed to work as a bronchodilator and decongestant.

  • Bronchodilators are drugs that improve blood oxygen supply by dilating blood vessels.
  • Decongestants are drugs that work as blood thinners to reduce blood pressure.

For horses with asthma, Bute relaxes the airways in the lungs of the animals.

In humans, it is approved to combat asthma via prescription in some countries in Latin America and Europe.

As per the World Anti-Doping agency, usage Clen is prohibited in almost every proffesional sport.

Clenbuterol has the chemical formula C12H18Cl2N2O and the chemical name Benzenemetanol, 4-amino-3,5-dichloro-α-[[(1,1-dimetyletyl)amino]metyl]-

Off-script use of Clen to shred fat and get lean has become very popular over the years.

Many professional athletes, bodybuilders, and celebrities have admitted or been caught with this chemical in their system.

It contains potent thermogenic attributes that make fat loss easy and quick.

How Does Clenbuterol Work?

Everyone who first finds out about Clenbuterol wants to understand how it can work to get them ripped.

Well, I have done the leg-work and found out that this steroid-like substance works in two ways:

Increases Metabolism

Yes, your basal metabolic rate will be heightened when you take this steroid-like chemical.

This starts a chain reaction causing the body to quickly metabolize and release stored glycogen into your bloodstream.

Since more glycogen is supplied to the body for use as energy, levels of stored glycogen are reduced.

Glycogen is most commonly stored in the liver and the skeletal muscles. It is the primary source of energy for the body. Glycogen is secreted when blood sugar levels decrease. 

So, when there isn’t sufficient glycogen to produce glucose, your body has to find alternative sources of energy.

These sources are proteins and fats.

Now, the body starts to use all the proteins & fats for more energy. Hence, there is a reduction in body fats.

Increases Internal Body Temperature

Clen causes the body’s internal temperature to rise, causing Thermogenesis.

This is mainly done by increasing cAMP levels and metabolism.

Thermogenesis is linked to increased metabolism as it helps increase the internal body temperature. This occurs when your body burns calories and fat to create energy and heat. 

A lot of us like it when we sweat a lot at the gym. Don’t we?

Thermogenesis caused by bute, allows the body to sweat more which also helps in faster calorie burn

And while you may be concerned about increased body temperature, the increase is insufficient to cause your body any harm.

Clenbuterol Increases Internal Body Temperature

What Are The Benefits Of Clenbuterol?

People buy the banned substance because of the benefits they can experience.

And these benefits are not just limited to weight loss either.

I have compiled a list of the most popular benefits:

Increase In Workout Performance:

Clenbuterol causes vasodilation to help the muscles get more oxygen-rich blood.

This allows muscle tissue to recover from fatigue faster. It also improves muscle strength and workout performance.

You should expect better workouts within the first few weeks of use.

Enhanced Metabolic Rate:

Clen stimulates the basal metabolic rate of the body, improving your ability to burn fat for fuel.

This allows more fat and calories to burn for the same amount of work.

An enhanced metabolic rate allows you to burn calories faster with the same amount of workout.

Causes Thermogenesis:

It can help increase your body’s internal temperature by up to 1 degree.

This activates the body’s fat-burning process (lipolysis) for the increased fat burn.

This causes increased sweating, and you should stay well hydrated when taking this steroid-like drug.

Promotes Muscle Gain:

Usage of Clen can increase lean muscle mass by 4.3% when on a 2-week cycle.

While this is not an anabolic steroid, it provides similar muscle gain benefits as steroid injections.

The increase in muscle mass and fat burn is the reason it’s popular amongst bodybuilders, both amateurs, and professionals.

Improves Oxygen Supply:

We now know that this chemical was initially designed to help treat asthma by dilating the airways.

Hence, it helps improve oxygen supply to and from the lungs.

Increased oxygen supply helps improve endurance and stamina. You won’t run out of breath as quickly when taking this pill.

More time on the treadmill!!

Suppresses Appetite:

It works to promote weight loss by suppressing appetite while burning stored fat.

I found that this chemical helps suppress your appetite by affecting hunger and satiety.

This is a benefit that many amateurs who want to get rid of their belly fat aim for.

Boosts Energy Levels:

Clen burns fat to produce energy.

It’s also a stimulant that provides similar benefits to ephedrine.

The stimulating effects of the pill help you gain more endurance and energy for your workouts.

Using this pill will let you work out harder and with greater intensity.

Clenbuterol Brands:

Tens of thousands of men and women have used this to get ripped and lose weight.

This is why multiple manufacturers sell Clen under different names.

The most common form used is tablets or capsules.

However, this substance is also available as inhalers, injectables, clen pumps, liquid syrup, powers, and spray pens.

The most common brands of Clen pills and liquids:
  • Alpha Pharma Astralean (40 mcg tablets)
  • Azncimittel Werk Dresden G Contraspasmina (20 mcg tablets)
  • Biornedica Foscama Clenasma (20 mcg tablets)
  • Boehringer Ingelheim Spiropent (20 mcg tablets)
  • Boehringer Ingelheim Ventipulmin (72.5 mcg/ml syrup)
  • British Dragon Clen (20 mcg tablets)
  • Chinoin Mexico Novegam (20 mcg tablets)
  • Duopharma Clenbuterol (20 mcg tablets)
  • EURO-MED Clen (40 mcg tablets)
  • Falqui I Contrasmina (20 mcg tablets)
  • Fidelis Cesbron (20 mcg tablets)
  • Genesis Labs Generic Clenbuterol (0.2 mcg tablets)
  • Hubei Huangshi (China) Clenbuterol (40 mcg tablets)
  • Jing Tan Generic Clen (40 mcg tablets)
  • Juste ES Ventolase (20 mcg pills)
  • LA Pharma Clenbuterol (20/40 mcg tablets)
  • Malay Tiger ClenoX (40 mcg tablets)
  • Meditech Clenbuterol (40 mcg tablets)
  • Nihfi (Bulgaria) Clenbuterol (20 mcg tablets)
  • Nimrod Dilaterol Clenbuterol (25 mcg/ml syrup)
  • Quimedical PT Broncoterol (20 mcg pills)
  • Richter A Ventipulmin (16 mcg/gram)
  • Salus I Prontovent (0.02 mcg tablets)
  • SB Labs Generic Clenbuterol (20 mcg tablets)
  • Shree Venkatesh Clenbuterol (40 mcg tablets)
  • Sopharma Sofia BG Clenbuterol (20 mcg tablets)
  • Thaiger Pharma Airclen (20 mcg tablets)
  • Thomae G Spiropent (20 mcg tablets)
  • Valeas I Monores (10/20 mcg tablets)
  • Von Boch I Bronchodil (10 mcg pills)
  • Yansuan Clenbuterol HCL (40 mcg tablets)

Get A Safe & Legal Supplement That Gives Clenbuterol Like Benefits

Precautions When Picking The Right Brand Of Clen:

You should carefully research the brand and form of Clen you plan to purchase.

This is as many brands have fillers and binders to increase pill performance. These fillers can cause unexpected or magnified side effects in some users.

Products that also contain other stimulants like Yohimbine and Ketotifen that may alter the side effects experienced.

Clenbuterol Brands

The manufacturers often mention the target user of these brands as horses for legality. However, people use these for off-script purposes themselves.

The Most Common Clenbuterol Cycle For Weight Loss:

Since bute has been used for cutting and muscle gain for years, people have found different ways of taking it.

For average users or those starting out with this stimulant, it’s recommended to take only clen.

But for bodybuilders, this chemical is often not enough to get truly shredded. This is why they stack this with Anavar.

Whether you are a professional, amateur, or beginner user, you can choose between the two most common Clen cycles:

On/Off Cycle:

The on/off cycle is the most commonly used cycle for dosing on Clen or other anabolic steroids.

In this cycle, you take the substance to be ‘on’ it for a set period. After this, you get ‘off’ the substance for a similar duration by not taking it.

Most people consider 2 weeks on and 2 weeks off to be acceptable.

The most viable theory behind this is to give your body and hormone levels time to reset themselves.

Some people also do the same with 4 weeks on and 4 weeks off approach.

Here’s an example of a 2 week on/off cycle for Clen:

On/Off Cycle Men (in mcg) Women (in mcg)
Day 1 20 10
Day 2 40 20
Day 3 60 35
Day 4 80 50
Day 5 100 65
Day 6 100 75
Day 7 120 80
Day 8 140 100
Day 9 140 100
Day 10 140 100
Day 11 140 80
Day 12 80 50
Day 13 60 34
Day 14 20 10
Day 15-Day 24 Off Off

Continuous Cycle:

The continuous cycle is as the name suggests, continuous. This cycle requires you to increase your dosage of Clen every week or two slowly.

This is continued until you reach the maximum safe dosage.

At this point, you slowly reduce the dosage to zero. When one cycle is completed, a two-week break is recommended to allow your body to center itself.

The most common continuous cycle lasts for 14 weeks.

Here’s an example of a 14-week continuous cycle for Clen:

Continuous Cycle Men (in mcg) Women (in mcg)
Week 1 20 10
Week 2 20 20
Week 3 20 45
Week 4 40 60
Week 5 60 70
Week 6 80 85
Week 7 100 100
Week 8 120 100
Week 9 140 100
Week 10 140 100
Week 11 140 100
Week 12 140 100
Week 13 80 40
Week 14 40 20
Day 15-Day 24 Off Off

Clen Cycle Myths:

Most people think that cycling the substance slowly is to avoid a backlash.

However, I have found this to waste time and energy for the user.

Establish Your Clenbuterol Cycle

According to my findings, you can step up your dosage to maximum over the weeks like in the continuous cycle.

After this, instead of slowly weaning off it, immediately drop to your base usage for a period before getting ‘off.’

This method allows less waste of resources and maximum performance boost but should not be used by first-timers.

Clenbuterol Side Effects:

Now that we have listed the positive aspects of this chemical, let’s take a look at the negatives.

Important: Like other performance-enhancing drugs, Clen comes with its fair share of side effects, both minor and major.

You should make sure to read this section thoroughly as using Clen may cause you to experience one of these.

Even so, I would like to point out that these side effects are not as common as other sites suggest.

Albeit, you may hear about people experiencing these frequently, especially if you visit clen forums.

Getting to it, this steroid-like chemical comes with a set of short-term side effects and a few long-term ones.

And here is a list of said side effects:

Short-Term Side Effects:

When I say short-term, I mean that these last for a short duration before going away.

Altering dosage or stopping use can eliminate the side effects.

On a side note, eating meat tainted with the chemical has led to cases of poisoning and hospitalization.

This is also why many countries don’t sell meat, like beef, from animals treated with Clen.

Here is a list of the short-term side effects of using Clen:

  • Headaches
  • Hypertension
  • Heart Palpitations
  • Insomnia
  • Increased heart rate
  • Restlessness/ Nervousness
  • Anxiety
  • Tremors
  • Breathing difficulty
  • Sweating
  • Dry mouth
  • Vomiting
  • Muscle cramps

Muscle Cramps Due To Clenbuterol Use

Long-Term Side Effects:

While it’s popular amongst athletes and celebrities, it has only been around for a few decades.

This, in turn, has limited the amount of data we have on the long-term effects of this substance.

I found four significant long-term side effects when I checked clinical studies online:

Reduction In Bone Density And Strength:

Having low bone density is common amongst bodybuilders.

This is because using Clen can affect the microarchitecture of the bones, resulting in increased bone fragility.

The risk of bone fractures increases because most bodybuilders are muscular and have low bone density.

Reduced Bone Density And Strength

Heart Muscle Degeneration:

Overdosing on Clen can lead to higher levels of collagen. But this collagen is not the one that makes your skin youthful and radiant.

Instead, collagen reduces the effectiveness of the heart’s pumping ability.

This causes undue strain on the heart muscles, leading to the degeneration of heart muscle.

Enlargement Of Heart Muscles:

The collagen that causes damage to the heart also results in the enlargement of the heart muscles.

It also causes arrhythmias in some cases.

This occurs when collagen affects the electric signals that help maintain a regular heartbeat.

Since the heart is no longer able to pump blood effectively, the heart muscles become enlarged.

This happens to maintain the required blood flow throughout the body.

Enlargement Of Heart Muscles

Detrimental Effect On Existing Heart Problems:

If you already have heart problems, you should also avoid using stimulants like this one.

This is due to the increase in blood pressure and heart rate that this stimulant causes.

The increased strain on the heart can hurt preexisting heart conditions. In some cases, exercising on clen can cause an aortic enlargement.

This increases the risk of aortic rupture and sudden death is possible.

Real People With Clen Side Effects:

I did some online research to check if people have suffered from side effects.

The best place to look was bodybuilding & health forums.

This is what I found:

This person was shaky, twitchy and had bad headaches after taking Clen.


This person warns about the usage of Clenbuterol after one of his friends had a massive heart attack.


Another person complaining of chest pain with Clen.

Clenbuterol Chest Pain

*Click on the images to view bigger

Celebrities And Athletes That Have Used Clen:

All major sporting committees and bodies have banned the use of Clen in professional sports.

However, some athletes continue using it to get lean to get that competitive edge over their competitors. 

You can even find this being used in Hollywood as well!!

Yes, celebrities do risk their lives just to look good on screen. 🙁

This is where being slim and sexy is a requirement for women to be successful.

And having bulging muscles and a ripped physique is a requirement for men.

This has led to many men and women in Hollywood using clen.

Some celebrities have admitted to using Clen to lose weight and getting slim.

These include Lindsay Lohan, Britney Spears, and Victoria Beckham.

Athletes that have tested positive for clen:
  • Adam Seroczyński (Canoer)
  • Alberto Contador (Cycling)
  • Canelo Alvarez (Boxing)
  • Carter Ashton (Hockey)
  • Erik Morales (Boxing)
  • Francisco Vargas (Boxing)
  • Guillermo Mota (Baseball)
  • Jessica Hardy (Swimming)
  • Katrin Krabbe (Athletics)
  • Kim Ji-heun (Swimming)
  • Lainer Bueno (Baseball)
  • Li Fuyu (Cycling)
  • Lucas Browne (Boxing)
  • Michael Rogers (Cycling)
  • Moises Cedeno (Baseball)
  • Nigel Levine (Athletics)
  • Petr Soukup (Bodybuilding)
  • Raul A. Mondesi (Hockey)

Clenbuterol Use In Sports

Is Clenbuterol Legal?

In some countries, you can legally purchase Clen, either with or without a prescription.

However, in the US, it is strictly illegal to buy or sell the substance.

It is also illegal to buy it online if you reside in a country that has made the substance illegal.

Countries like China, Bulgaria, and Russia produce many of the clen brands used today.

However, it’s illegal for human use in most countries.

Only a certified veterinarian can administer this drug to treat breathing problems in horses.

It can be risky to buy bute in the US or UK but it’s easier in some other countries.

Unfortunately, you can’t bring it back to the US with you. Actually, you can! But you might end up in jail!!

Should You Buy Clenbuterol Online?

Absolutely Not!!!

It is a bad idea to buy it online because of a few reasons:

Internet Footprint:

These days, the government can track what you have been doing online very easily.

For one thing, hiding anything from the internet watchdogs is difficult.

So, buying Clenonline will end up leaving a paper trail.

This means that if the authorities wanted to, they could find out about your purchase, even from years ago.

Unknown Quality:

Buying anything online comes with a degree of risk when it comes to the quality of the product.

This is even more true with purchasing it online.

Most manufacturers design their products for use on horses, not humans.

We humans are not like horses. Hence, avoid what is made for them.

Lack Of Reputed Manufacturers:

You probably haven’t heard of most of the manufactures of the brands I have mentioned earlier, right?

So, how are you going to find out if the manufacturer of the product you are purchasing is sound?

This lack of information means risking your health and future for people making your pills in a faraway country.

Clenbuterol: Is It Worth The Risk And Dangers Involved?

I would like to start off by saying that this steroid-like chemical can help give visible bodybuilding benefits.

However, this is only one side of the coin.

To make an informed decision on whether you should use Clen, also take note of its negatives.

On a whole, I recommend you not use this chemical for weight loss or bodybuilding.

I believe that you would be more willing to give up on it if you are provided with alternatives.

The alternatives I found use natural ingredients to produce the same fat-burning results as the original.

Unlike the banned chemical compound, they don’t cause the same side effects.

You can also purchase and use them legally.

Clenbuterol Alternatives Provide Similar Results Without Side Effects

And depending on the product, you can also expect the same fat-burning results as Clenbuterol.

I should also mention that the legal steroids aren’t as quick to show results as the banned chemical version.

Even so, the lack of side effects and being able to purchase legally makes the alternatives worth considering.

Leave a Comment