Clenbuterol Review, What It Is, Results, and Guide for Bodybuilding

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Clenbuterol was first invented to successfully treat people with asthma. Clen opens up the asthma patient’s airways, enabling better breathing and better oxygen inhalation.

However, researchers later discovered clenbuterol to be a strong thermogenic, as it stimulated beta-2 receptors; thus people who took the drug experienced rapid fat loss.

Thermogenic = increase in body temperature.

Thermogenics promote fat loss as the body has to work hard to regulate your body temperature back down to normal…which in turn burns calories.

Clen has a powerful stimulative effect on the central nervous system, causing epinephrine to be released and a person’s heart rate to increase. As a result, their metabolism becomes notably faster and energy levels are spiked.

As you can imagine, despite clenbuterol not having any anabolic effects; it’s ability to boost a users metabolism will help burn more fat during a cut. And it’ll help keep energy levels high, when bodybuilders typically become sluggish on lower calorie diets. Users also report of more intense workouts due to this added adrenaline, whereas usually workouts can often suffer due to a lack of energy when dieting.

If you’re chubby, clen will make you slim.

If you’re lean, clen will get you ripped.

If you’re very lean, clen will get you shredded.

Bodybuilders often start taking clenbuterol 2 months before a competition, when trying to reach extremely low levels of body fat – being 4% or lower.

Clenbuterol Review

The following is a real clenbuterol review by an anonymous person, who will be known as Juice Guru.

I’ve performed clen cycles for many years now, and people always ask me questions about this drug; so this article is dedicated to helping others understand the pros and cons of clen.

How Clenbuterol Works

Clenbuterol is a thermogenic cutting agent that works by increasing a person’s overall body temperature; which in turn boosts their metabolic rate.

Some athletes and gym-goers use clen for several different reasons. Athletes use clenbuterol as a performance-enhancer, increasing their energy levels/endurance, as it opens up the airways for increased oxygen delivery to the muscles. Hence how clenbuterol was first designed as a treatment for asthma.

Also clen’s ability to burn fat can help make an athlete more functional due to weighing less (especially advantageous in endurance sports).

The primary reason why bodybuilders use clenbuterol is in a cutting cycle to help them get extra shredded. This can be for vanity purposes or if they’re about to compete on stage against other bodybuilders.


Below is a summary of all the pros and cons of using clenbuterol that I’ve experienced over the years.


  • Great fat burner
  • Anti-catabolic

Unsurprisingly, many people sing the praises of clenbuterol when it comes to fat loss. I’ve experienced as much as 4lbs of weight loss in the first week of using clen, so it kicks in pretty fast.

However, don’t expect clen to build a tonne of muscle on clenbuterol, as its anabolic effects are mild.

You may build muscle on clenbuterol, but it’s unlikely to be anything significant.

Some users may experience more muscle and strength gains than others, depending on dose/cycle length/genetics. In scientific studies, clen has proven to increase LBM (lean body mass) in animals – such as horses.


  • Hypertension
  • Insomnia
  • Sweating
  • Shakes

There’s no getting away from the fact that clenbuterol is a banned substance by the FDA and it will cause a spike in blood pressure. After your cycle, your blood pressure will go back to normal and may even be lower than before because of fat loss. However, if abused clenbuterol may cause long-term side effects, such as enlargement to the heart.

One guy I spoke to claimed clen had practically given him a heart condition from just 1 cycle, but admitted to increasing the dose by A LOT early into his cycle. So although clenbuterol isn’t a steroid, if you’re going to use it, do so with extreme caution, because like with any other drug, it has the potential to be dangerous.

40mcg is the average dose that’ll produce good fat loss (in men). If you’re a beginner, there’s no need to go to much higher than this amount, as this’ll result in too much adrenaline and your blood pressure spiking excessively. A common clenbuterol cycle protocol is to use it for 2 weeks on, followed by 2 weeks off.

This way your BP doesn’t stay spiked for too long a time period.

flushed skin from clenbuterol

The reason clen spikes blood pressure considerably is because your body will produce a lot more adrenaline than usual, because clen stimulates the nervous system; shifting your body into fight or flight mode. This extra adreanline heats up the body and increases physical symptoms such as sweating and dehydration.

…so make sure you drink plenty of water whilst taking clenbuterol.

But clen can also cause adverse mental side effects such as anxiety/depression due to an overactive mind. Your body is only designed to be in fight or flight mode for a short period of time, so if you’re constantly in this state you will start to see normal things as potential threats. Which is essentially what anxiety is.

Clenbuterol, also known as clen, was originally formulated for the treatment of breathing disorders that are related to recurrent airway obstruction (RAO) and inflammatory airway diseases (IAD). However, a number of scientific studies confirmed clen to be an effective fat-burning and muscle-sparing supplement.

Consequently, clenbuterol has been a favorite supplement among bodybuilders for over 25 years, as well as fitness professionals, athletes, models, celebrities; and everyday gym-goers who simply want to lose fat.

Clenbuterol’s usually taken in pill form, however it’s also available via injection, syrup or inhalation.

If you’re interested in taking clenbuterol, it’s important to know about it’s benefits and side effects. Read on to find out how it can help you with your bodybuilding needs.

Clenbuterol Steroid Cycles

Clenbuterol Cycle for Beginners

When getting started with clen, the general recommended daily dose for males is 40 mcg, and 20 mcg for females. It’s not advised to start on a higher dose than this as you run a greater risk of experiencing unwanted side effects. In short, your body will need to adapt to the effects of clen, so it makes sense to start with a smaller dosage and increase it gradually throughout the cycle.

For best results, take clen in the morning or afternoon if you’re working out later that day. Taking this supplement after dinner could give you insomnia as it stimulates your nervous system; resulting in an overactive mind.

A typical clenbuterol cycle length for beginners is 2 weeks, though some individuals may use a week, 3 weeks, 4 weeks or a ten-day cycle instead.

Other Cycles

For maximum safety, a users dosage needs to be adjusted appropriately as you progress further into your cycle. To help with that, here’s the most common, dosing strategies; ensuring your cycle’s as safe as possible.

Conservative Cycle

With this approach, you’ll gradually increase the initial dosage by 20mcg every 2 weeks as needed. This cycle ensures that the body isn’t caught off guard, allowing it to continue guessing and not fully adapt to the compound; making it effective throughout the whole of your cycle.

Some people however go up to 4 weeks without ever raising the dose. Thus they’ll have the same amount of clenbuterol in their system during their cycle, meaning their metabolism may not be firing as strongly as it could (from increasing the dose in stages). In fact, it’s advisable not to cycle clenbuterol at the same dose for any longer than 6 weeks.

Aggressive Cycle

This is one of the most popular approaches used amongst bodybuilders. This method allows them to consume a higher dose of clen for a shorter period of time, which tends to give users better fat loss results. This method simply involves running clen for 2 weeks on and 2 weeks off with a steady, incremental plan.

You’ll start with a smaller dosage, preferably 40mcg for men and 20mcg for women, and increase the intake by 20mcg every 2 days. Be sure to reach the maximum dosage after 14 days of dosing. Following this, you should rest for 2 weeks.

As you move into the next 2-week clenbuterol cycle, make sure the dosage starts at the maximum, where it was left off. The dose will remain the same throughout the rest of the cycle.

What is the Maximum Clenbuterol Dosage?

The maximum daily dose for men is 140mcg, and for the female 120mcg. However this is a hefty dose that will come with more side effects, including: high blood pressure, increased heart rate, sweating, shaking and anxiety. Users are also urged not to use clen for more than 16 weeks in one year for optimal long term cardiovascular health.

Achieving that perfect physique you’ve always dreamed of may require using supplements such as Clenbuterol. The secret to success and maximum safety when using clenbuterol is making sure you take right dosage (which is often determined by your gender, health and experience).

Clenbuterol Dosage (for Maximum Fat Loss)

It’s important to understand when taking clenbuterol to not overdose, as doing so could would be dangerous. This is because many new gym rats may decide one day to take clenbuterol, don’t care about how much they take of it…then bam – they’re in hopsital because of their naivety. If you want to look good and feel great with the help of clenbuterol there are no shortcuts. A good diet and workout plan is still recommended whilst taking clen (if you want maximum weight loss).

Initial Clenbuterol Dosage

The end objective when taking Clenbuterol is sustainable weight loss through spiking your metabolism. Keep in mind that if you’re a beginner, small amounts of clen will go a long way in improving your BMR (metabolism).

40mcgs daily is an appropriate starting dose for men

Whilst 20mcg daily will work just fine for women. It’s better to begin with this small dose, as easing into it reduces the risk of developing complications and side effects.

Keep in mind that the human body adjusts to the effects and can become less sensitive to it’s stimulating effects over time, so the dosage will need to be adjusted to coincide with how your body responds. It’s not in your best interest to start with a high dose. This would be like jumping in the deep end of a swimming pool when you’ve just taken your arm bands off.

Increasing Your Dose

The further you advance into a clenbuterol cycle, the more your dosage will need to be adjusted to continue making gains. A slow and steady increase gradually works best. Since this supplement is a beta 2-stimulator it needs to be taken in a cycle so that your body can adapt more efficiently.

How the body adapts differs from one person to another. A maximum dose of Clenbuterol can enhance metabolic function for up to a maximum of 6 weeks.

As the 6 weeks come to an end the effects will fade, but the fat loss you experienced during your cycle is permanent. The typical reaction in most users is that they want to increase their dosage significantly after they begin to plateau. However, according to weight loss experts, this is not a wise move as it’ll increase the chances of desensitization. Thus it’s best to come off cycle for a few weeks and then re-cycle rather than upping your dosage.

Here’s how to do it right…

1) The conservative approach

This is the best and most effective protocol in the long-term, as it involves slowly and gradually raising your dose. Increase the initial dose (40mcg in men and 20mcg in women) by 20mcg’s every fourteen (14) to seventeen (17) days. When using this regimen, your clenbuterol cycle should not exceed six weeks.

2) The Aggressive Approach (2 weeks on/2 weeks off)

If you’re willing to work out more regularly and melt fat even faster, then you can go with a more aggressive approach. This is most common method among bodybuilders who might be prepping for a competition. It entails 2 weeks of intense consumption with a steady incremental dosing scheme – followed by 2 weeks off. If the initial dosage was 40mcg for men and 20mcg for women, it will be increased every two days, with maximum dosage will be reached after 2 weeks. Once the maximum dosage is reached, the 2 week rest period begins.

Then after this rest period is over, a 2 week cycle begins again.

These two methods may not be the only ones but are the most advisable and recommended by medical experts since they’ve been tried and tested; making them as safe and effective as possible.

Conclusion on Dosages

Always keep in mind that clenbuterol should be cycled properly (not only to avoid bad side effects), but also for effectiveness. Although a user’s gains from a clenbuterol cycle will vary from person to person; the approaches mentioned in this article have been proven to be the most effective of cycles – helping bodybuilders burn fat and retain muscle mass.

Note: It’s always advised to get a medical checkup before using clenbuterol.

Clenbuterol Review: A Summary

If the wrong person takes clen, things can turn pretty ugly. I.e. a person someone whose had previous heart problems or already has high blood pressure shouldn’t even be thinking of taking this cutting agent.

However, many people in good health see taking clenbuterol as a risk they’re willing to take, because although their cardiac health will decline temporarily on a cycle, they’re happy to experience the fat loss and the overall positive effect it has on their body composition.

Ultimately, you don’t NEED clenbuterol to get shredded, as diet can do this alone. But if you do take it, you’ll burn more fat as a result.

If you’ve got a substantial amount of fat that you want to get rid of, you can stack clenbuterol with other fat burning steroids such as:

  • Winstrol (stanozolol)
  • Anavar (oxandrolone)
  • Testosterone

Stacking steroids together like this usually results in much better long-term gains.

Clenbuterol for Diet Plan Tips

1. Calorie Deficit

This is, of course, the first step to a successful cutting diet.

It’s no secret that in order to cut weight, you must eat in a deficit of calories.

calorie deficit = eating less calories than what your body burns in a day.

A lot of people get caught up in things like, what fat burners to order or what cardio workout they should do today – but first and foremost, if you’re not eating in a calorie deficit you’re not going to lose weight.

If you’re serious about getting results on clenbuterol, you’ll track your calorie intake. Monitor how many you consume on average each day, and stick to this number. If you’re not losing weight after a week on the same calories, you know you need to lower this number until you’re losing weight at a rate you’re happy with.

If you want to burn fat and retain muscle – aim to eat in a small calorie deficit of 500. 

Although dieting and counting calories isn’t the definition of fun, it’s the only way which guarantees to get you leaner. All the tedious work of counting calories and eating clean will pay off when you hit your goals and stand infront of the mirror with the body you’ve craved so long for.

2. Get Rid of Sugary Foods/Drinks

Excessive consumption of high-sugar foods and sweetened drinks have been linked to weight gain, as they
are a major (and unnecessary) source of calories, which have no nutritional value. Cutting your sugar intake is, without a doubt, the easiest and quickest way to make the extra calories which are ‘nutritionally empty’ disappear.

We’d also recommend consuming the sugars you do get from your diet from fruit. Although some fruits do have a lot of sugar (fructose), they’re still very beneficial for your health (unlike processed sugars) because they contain fiber, which prevents your blood sugar levels from crashing.

Fructose also keeps your energy levels high (no falling into any food comas), which is key when cutting because this is a time when you’re more likely to feel fatigued and low on energy.

3. Reduce Dairy Products

One of the unknown attributes of clenbuterol is that it causes you to lose water, helping you to look even more ripped.

Dairy products can have the opposite effect when it comes to water in the body, often causing it to hold in all the wrong places making you look bigger than you are.

Because dairy products contain lactose they often cause you to retain water which collects inbetween the skin and the muscles; making you look puffy and bloated. Thus, if possible, try to cut out all dairy products except for butter. Butter has a low lactose content, meaning it won’t cause you to retain excess fluid.

Note: having milk in your cereal is fine and won’t effect you too much, but if you’re drinking glasses of milk or having yogurts daily – this will make a difference in your body composition.

4. Consume Healthy Fats

If you want to burn fat and achieve long term results, it’s probably a wise idea not to eat a high-fat diet, as fats are the highest calorie macronutrient.

However, it’s still a good idea to consume some healthy fats to keep your testosterone levels high. A mistake I often see dieters make is when they cut out ALL fats from their diet. As a result they feel weak and lethargic because their testosterone’s taken a hit. Fats are crucial in administering testosterone, so it’s key to still consume some fats when you’re cutting on clenbuterol.

Healthy sources of fats include: natural peanut butter, legumes, whole eggs, nuts, salmon and lean portions of red meat. But you should also take note of the amount you consume. The human body only typically needs a very small amount of fats to administer testosterone; so if you over do it you’re likely to pile on the weight. Try and consume at least 20-30g of fat in your diet each day for optimal hormone function.

5. High Protein Diet

Usually when a person takes clenbuterol, they don’t just want to burn fat, but also want to keep hold of their muscle. Protein is the main component of your muscles and skin tissues which are continuously being repaired and replaced with new protein. Therefore, you must consume a good amount of proteins every day to help retain your muscle mass.

Bodybuilders usually follow the 1 gram of protein per pound of bodyweight rule. Anything more than this is deemed excessive and will no longer be beneficial for muscle retention/growth.

Is It a Cutting Steroid?

A lot of people out there tend to see clenbuterol as a steroid.

The truth is that it isn’t…the drug belongs to a category of substances known as beta-2-agonists. It’s not a stimulant either, but it does cause some reactions similar to stimulants (such as caffeine or ephedra). The main difference between clen and other stimulants, is that it’s not addictive and is rarely subject to abuse by its users.

When clenbuterol was first developed, it was used as a form of treatment for asthma in horses. However, over time, advancements have been made to take advantage of its efficacy in human applications. It’s still used on horses but has become wildly popular in helping people lose weight all over the world.

Clenbuterol Weight Loss

The transition from using clen to treat asthma and then for weight loss was actually a bit of an accident. Scientists discovered that one of the effects of clenbuterol was that it caused fat loss, as well as muscle gain.

This resulted in humans using clenbuterol to improve their body composition. At first, clenbuterol was used by just female athletes but its use caught on, and now it’s just as popular among men trying to lose weight and get ripped. However, female athletes are especially fond of this drug as it doesn’t have any androgenic properties – meaning those who use it do not develop deep voices, higher hairlines or acne. It keeps their estrogen levels firmly in place, so they can still retain looking very feminine.

In both men and women, clenbuterol works by stimulating the increase of your Basal Metabolic Rate (a fancy word for metabolism), which leads to a higher daily calorie burn.

Tips for FAST Weight Loss on Clen

Clenbuterol comes in a number of forms. You can use it as powder, spray, tablet or liquid drops. It’s believed that it may work best as liquid drops, as it enters your system quicker. There’s no definite dosage as to how much you can use at one time.

The general agreement is that women should take 20mcg of this drug a day while men can take up to twice this amount. It’s important to note that amounts will vary depending on the individual, but a good idea would be to start slow and allow the body to get used to it over time. Some users may see this approach as taking things slow, but it’s a logical approach as it allows you to minimize the risk of side effects.

For fast weight loss, you’ll need to take your dose in the morning before taking any food. The reason is that clen works by suppressing your appetite for the rest of the day. This is the most effective way to prevent any potential cravings and stick to a calorie-restricted diet. Taking clenbuterol on an empty stomach is also a nice way of avoiding some side effects, such as nausea. Studies indicate that since insulin counteracts the effect of the drug, taking it on an empty stomach ensures the best results (and less side effects). Those who take clenbuterol in the morning also perform better (during exercise) over the course of the day compared to those who choose other times.

…So expect more intense workouts when you take clenbuterol in the AM.

How long does it take to lose weight on Clenbuterol?

When used in moderate amounts and accompanied by the right diet as well as exercise regimen, you’ll experience significant weight loss in the first two weeks. Users have reported losing anything between 4 to 6lbs (in the first 14 days).

Clenbuterol is mainly obtained via the black market (although this method isn’t recommended). Always be sure to buy clenbuterol from a reliable seller and stick to the recommended dosage. For quicker results, you can also stack it with other cutting steroids such as winstrol or anavar.

Clenbuterol for Women

Some believe that clenbuterol actually works better for women than it does for men. This is because women naturally have a slower metabolism (on average) compared to men; thus women often find this extra calorie burn more beneficial.

Clenbuterol also does not convert into testosterone and affect male hormones in any way shape or form.

Each woman has a small amount of the male hormone – testosterone. And as you can imagine, when women take testosterone-boosting steroids, they start to experience hair growth, deeper voices, clitoral enlargement and hair loss (on the scalp). Some of the steroids which can cause these effects are: dianabol, anadrol and trenbolone.

Because clenbuterol won’t cause women to experience develop male characteristics, it’s a highly coveted fat burner. It’s not just female bodybuilders and athletes who take clen, but also average-Joes who simply want to lose fat and look better.

Clenbuterol Side Effects in Women

Clenbuterol’s side effects are the same for both genders. It’s important to point out that many people get on okay with clenbuterol hence how it’s so popular, however negative side effects are possible and they include:

  • Insomnia
  • Increase in body temperature (sweating)
  • Anxiety
  • Higher blood pressure

If you do experience any of the above side effects, they will discontinue once you stop taking clen.

Thus if you’ve got heart disease or you have regular panic attacks due to anxiety – it wouldn’t be wise to take clen. Also if you have trouble getting to sleep at night due to racing thoughts, clen won’t help this situation get any better.

These are POSSIBLE side effects. There are people who take clen without noticing any adverse effects. Due to its popularity, many believe that clenbuterol’s pros far outweigh the cons.

How to Maximize Fat Loss on Clenbuterol for Women

Clenbuterol will spike your metabolism enormously, but that doesn’t guarantee fat loss by itself.

If you take clen, but binge on McDonald’s and Twinkies…shoveling in 4,000 calories a day; it’s possible you won’t see any results from clenbuterol.


For maximum fat loss, eat in a deficit of calories. This doesn’t mean that you have to cut out junk food and eat 100% clean and boring. But instead, simply monitor your calories and consume less calories than what your body burns in a day.

The best way to know if you’re in a calorie deficit is if your stomach feels empty. If it does, congratulations you are in a deficit. If you feel full and satisfied, the chances are you’re not in a deficit. And if you’re really starving, this is a sign that you’re in a BIG deficit.

…In which case you can eat a little more if you want.

For RAPID fat loss, regularly perform intense cardio on an empty stomach in the morning whilst taking clenbuterol. When you do intense exercise on an empty stomach, your blood sugar levels are low; which means your body cannot use glycogen (sugars) for energy.

So instead the body taps straight into fat stores as its main energy source…and that’s why so many sing the praises of HIIT (high intensity interval training).

…Add clen into the mix and you’re going to be melting fat faster than you can blink!

Stack With Anavar for Better Gains 

Anavar is another cutting steroid that is very female-friendly and when stacked with clen; it will help you burn even more fat.

Anavar will also help women increase their strength in the gym. So if you lift weights, you’ll be able to lift a lot more weight than usual…pretty cool huh?


Anavar will help you preserve muscle whilst dieting but it’s not likely to result in significant amounts of muscle mass. So a woman on anavar doesn’t have to worry about looking too bulky.

Clenbuterol’s Benefits:

Clenbuterol’s results differ from person to person, however the most common benefits of taking clen include:

  • Elevated metabolism
  • Increased energy
  • Increased strength

The reason why clenbuterol is so effective at burning fat is because of it’s ability to spike a users metabolism. Clen does this through the process of thermogenesis. This is where your bodies overall temperature increases due to extra adrenaline production. Then because your body wants to keep a level of homeostasis, it works hard to cool it back down again.

This constant regulating of your body temperature is the reason why you’ll burn a lot more calories on clen. Consequently, you’re more likely to under-eat and burn fat.

Just imagine a 40 year old man reversing the clock and having the same metabolism of what he had in his teenage years. This is essentially what clenbuterol does, enabling you to get away with eating more food and still lose weight.

How Much Weight Will You Lose on Clen?

As a general rule, you should be looking to burn 1% of body fat each week you’re on clenbuterol.

If you take it for 8 weeks you should have burned at least 6% body fat.

6% may not sound like a lot, but this may translate to a good 16lbs of weight loss.

Losing this much weight will make a huge difference in the mirror  Your muscle tone will increase significantly and your 6 pack abs will become more visible.

Clenbuterol Results: Before and After Pictures

One of the highest-profile celebrities who (I believe) has taken clenbuterol is Wolverine, aka Hugh Jackman.

Hugh was lean in the very first X-Men movie, then got SHREDDED in X-Men origins: Wolverine…then continued showing off his ripped physique in the rest of his Marvel films.

hugh jackman clenbuterol results before and after

The reason why I believe Hugh was taking clen is because it’s known for giving users a red-look to their skin. This is a sign of an elevated temperature, caused by the thermogenic effect of clen.

In Days of Future Past, Wolvie is seen with this flushed look to his skin…

flushed skin from clenbuterol

How to Maximize Results on Clen

How much fat you’ll burn on clenbuterol will heavily depend on:

  • How hard you workout
  • How strict your diet is


If you take clenbuterol, but your workouts are lousy – don’t expect miracles. Guys who take clenbuterol can get insanely shredded, but the key is to combine this cutting agent with intense workouts and a fierce work ethic.

For maximum fat loss when cutting, I recommend you do regular cardio to increase your calorie expenditure. I personally love doing HIIT (high intensity interval training), because of it’s effectiveness at removing stubborn belly fat.

I hop on the seated bike and do 30 second sprints (as fast as you can!), followed by 30 seconds of rest. You should repeat this for 20-30 minutes, based on how well you’re coping.

…probably not too well if it’s your first time!

This high intensity will help spike human growth hormone levels, allowing you to burn even more fat.

Your Diet

When I say be strict with your diet, I don’t mean by eating clean/boring foods all the time.

I mean you’ve got to constantly eat in a calorie deficit.

You can eat whatever junk foods you like and still get ripped, as long as you’re consuming less calories than your body burns.

What to Stack Clenbuterol With for Better Results?

You can expect to melt fat even faster if you use other cutting steroids in the same stack as clen.

Here’s some of the best cutting agents:

  • Anavar
  • Winstrol
  • Testosterone

Anavar is another incredibly effective fat burner. Winstrol is a great fat burner, but equally good at building muscle. And testosterone is awesome for those looking to build muscle and burn fat at the same time.

Clenbuterol Dosage

Regardless of where you buy clenbuterol from, make sure you stick to the dosing guidelines outlined on the bottle. If you’re buying from the black market you might not have a recommended dose on the label. In which case, don’t take more than 20 mcg (or one tablet) per day. On this dose you should see visible results within a week.

Clenbuterol Half-Life

Clen’s half-life is between 12-48 hours, thus after taking your first dose, it’ll take as long as 2 days for it to leave your body. The active life of clenbuterol is 72 hours, which is when it’ll completely leave your system.

Thus if you had a drugs test on Sunday and it’s Monday, you’d need to take your last dose of clenbuterol by Tuesday or Wednesday (latest) – if you wanted it to completely leave your system.

When you have a good knowledge of a drug’s half life you can understand how to get better gains from your cycle, because you’ll know how to keep a constant flow of clenbuterol in your bloodstream, maximizing fat burning. It can also help you beat a drugs test by understanding when it’ll fully leave you body (if your employer tests for clen).

Now.. Clenbuterol Benefits for Bodybuilding

1. Increases Metabolism/Burns Fat

Clen’s ability to burn fat is what makes it famous, but how does it work exactly?

Clenbuterol’s proven to boost the metabolic rate of the body in a process commonly known as thermogenesis, which plays a major role in combating excess weight. Thermogenesis is the process where your body’s temperature increases. With your body desperately trying to keep a homeostasis, it tries to cool itself back down to normal.

As a result of this ‘constant cooling’, the body burns additional calories and thus a users BMR increases. The longer you take clen for, the more spiked your metabolism will be.

Clenbuterol also promotes lipolysis, the process where your body draws on stored fat as fuel and helps to give you more energy.

By increasing the heat and energy produced in the mitochondria cells and stimulating the central nervous system, you’ll burn more calories and fat in a shorter period of time. Clenbuterol’s fat loss benefits are pretty dramatic in the first 2 weeks of use. Clenbuterol’s also effective at reducing stubborn fat, particularly in the visceral and abdominal areas; which is often the hardest places to lose fat from.

2. Increases Blood Flow and Oxygenation

Initially, clen was used to treat asthma patients because it improves aerobic capacity and boosts oxygenation, as well as transportation of blood in the body. Bodybuilders can also experience a whole host of benefits from having increased blood flow and oxygenation, without necessarily being an asthma patient.

With more oxygen flow, you’ll increase your body’s muscular endurance. This is very important when you’re training in the gym, as it’ll help you to train longer. It will also speed up your recovery levels in-between workouts, enabling you to increase your training frequency.

Clen will also reduce any muscle soreness/pain that you can experience from a tough workout. Delayed onset muscle soreness is a tough reality for many dedicated weight lifters; however this effect is unlikely to happen on clenbuterol due to its positive effect on muscle recovery.

Thus it comes as no surprise that clenbuterol is talked about highly by thousands of happy users.

3. May Build Muscle (Small Amount)

Human studies on Clenbuterol show that the supplement has a positive effect on skeletal muscle. Clen has long-acting systemic beta 2-agonists, which can increase the size of skeletal muscle fiber and accelerate the creation of new muscle tissue generation.

Although clen isn’t as anabolic as steroids, it’s shown to be effective at getting rid of the stubborn fat whilst simultaneously gaining lean muscle mass.

Animals studies also support clenbuterol increasing lean body mass (seen in rats, mice and horses). It’s believed that clenbuterol’s anabolic properties are the result of it increasing protein synthesis levels.

Some bodybuilders don’t notice much, in regards to muscle gains on clenbuterol, however other users swear that it helps them add lean mass. Thus, more research is needed before clen’s classed as a muscle-building drug.

So, it may not be wise to use clenbuterol during a bulking phase as its muscle-building effects are generally only mild. However, it does have muscle preservation effects, making it very beneficial to use during a cutting cycle.

Preserving muscle mass, whilst losing fat, is one of the most difficult goals for a bodybuilder to achieve.

When you preserve your muscle tissue, not only are you keeping your hard-earned muscle in-tact; but your metabolism will also remain elevated, enabling further weight loss.

4. Increases Energy Levels 

goku showing high energy levels

Clenbuterol stimulates the central nervous system and thus increases your heart rate and adrenaline levels. As a result, users often report having higher energy levels throughout the day; and increased motivation to achieve their goals.

This adrenaline-like effect also increases the intensity of users’ workouts, helping them to lift heavier weights, perform more reps; or simply workout for longer periods of time. This can indirectly help a user increase strength, build muscle; or burn more fat.

Higher adrenaline levels can result in a user feeling somewhat ‘hyper’. However, if you consume stimulants on a daily basis such as caffeine, in the form of cups of tea or coffee; this effect isn’t likely to be too extreme.

5. Appetite suppression

Even though clen is typically identified as a metabolism-stimulator for weight loss, one of clenbuterol’s little-known benefits is appetite suppression. Research confirms the supplement works by stimulating a very sensitive beta 2-adrenergic system, which has a profound effect on the feeding behaviors in humans. This means you’re not likely to feel hungry throughout the day and it may stop all cravings.

This is very beneficial if you struggle to eat in a calorie deficit. Consuming less calories than your body expends on a daily basis is crucial for fat loss; thus by taking clenbuterol, you’ll naturally feel less desire to eat larger portions.

6. No Testosterone Suppression

gorilla with high testosterone

Clenbuterol isn’t a steroid, however it’s often mistaken as a cutting steroid; due to its powerful fat-burning effects. The main difference between cutting steroids and clen is their effect on testosterone levels.

Cutting steroids will shut down test levels, meaning that it can take several months after a cycle finishes for natural testosterone production to return to pre-cycle levels.

However, clenbuterol has no obvious effect on testosterone levels, thus when you finish your cycle, your testosterone levels will stay in tact.

Testosterone also helps to burn fat, so keeping this hormone elevated is key to long-term fat loss.

7. Diuretic-Effect

Clenbuterol does have mild diuretic effects, meaning you’ll lose water weight, as well as fat mass on this drug.

This is due to increased sweating, as a result of thermogenesis heating up the body. Consequently, users sometimes report urinating more than usual when they start taking clen.

Losing water weight can make a bodybuilder look more aesthetic, due to it increasing muscle definition and reducing bloat. This makes it a popular fat burner in the summer, when people are trying to look as tight and toned as possible.

Clenbuterol Results

sylvester stallone before after fat loss
Typical clenbuterol transformation

Weight loss can be dramatic whilst using clenbuterol, especially if the user’s eating in a calorie deficit and working out regularly and intensely throughout a cycle.

How much fat you’ll lose will depend on how you respond to the drug, your genetics, diet, workouts, dose and how long you cycle for. However, on average, users can expect to lose 8lbs from 4 weeks on clen.

If you combine clenbuterol with thyroid hormones such as Cytomel, you can increase thermogenic activity even more than a clen-only cycle.

Also stacking clenbuterol with cutting steroids, or human growth hormone, will further accelerate fat burning (and muscle retention).

Here’s a before and after picture of Sylvester Stallone. We believe he’s likely to have used clenbuterol for this transformation. He has flushed skin, a visual sign of thermogenesis in action.

Is Clenbutrol Safe?

Clenbuterol is not currently approved for human-use. Thus it’s deemed unsafe by the FDA. However, doctors do prescribe clenbuterol regularly to those suffering from asthma.

Both of these statements should indicate to users that there are dangers, however if clenbuterol’s used sensibly (especially under medical supervision) for a short period of time, side effects are unlikely to be severe.

Here’s some adverse effects that can happen on clen:

  • Increase in blood pressure
  • Insomnia
  • Increased sweating
  • Possible anxiety
  • Jitters (shaky hands)

Clenbuterol Side Effects

An increase in blood pressure is probable due to clenbuterol constricting blood vessels, making it more difficult for blood to flow to and from the heart. Thus if you have a history of heart disease or have existing high blood pressure, you should stay away from clenbuterol. However, in most users, blood pressure will simply rise a little and then drop back down once they stop using the drug.

Because clenbuterol increases adrenaline output, this can cause a user to become excessively stimulated in the evening, leading to insomnia. To prevent this side effect, the user can take pills earlier in the day. However, make sure there’s a gap of at least a few hours inbetween each pill to minimize adverse effects (you don’t want to take a high dose in a short space of time).

Increased sweating is a common reality among clen-users, especially towards the end of their cycle. This is a good sign, as it’s proof of thermogenesis (increased body heat), which is key for fat loss.

Be sure to drink plenty of water on clenbuterol to reduce the risks of dehydration.

Anxiety is a possibility for anyone who takes clen or stimulants in general, due to them initially increasing dopamine levels (the feel good hormone), but later reducing serotonin levels (the neurotransmitter essential for mental well-being).

Like alcohol withdrawal can cause the shakes, so can clenbuterol (particularly in the hands). The only way to prevent this is to keep your dose low-to-moderate.

How to Take Clenbuterol

Clenbuterol usually comes in 20mcg tablets. Bodybuilders will typically take 1-2 tablets a day (depending on their tolerance), and increase their dose by 0.5-1 tablet every 3 days

In terms of cycle duration, less is certainly more on clenbuterol. This is because after a certain period of time, clen will stop being effective for fat loss, because of receptor down-regulation.

Clen usually starts to wear off after 4-6 weeks. Thus it’s optimal to keep cycles short, otherwise you’ll be wasting your money.

You can tell if clenbuterol’s effects are wearing off by monitoring your body temperature. If your temperature begins to drop, this is a sign of clen’s thermogenic effects decreasing.

Experienced bodybuilders who’ve built up a tolerance to the drug, can adopt an aggressive dose to burn more fat (some do this before a competition) and take as much as 120-160mcg a day (6-8 tablets).

High doses will cause more side effects, especially in terms of strain on the heart and elevated blood pressure.

With higher doses, the cycles should become shorter. When taking a higher dose, 2 weeks on and 2 weeks off is a common protocol. Also short cycles will prevent your body from getting used to the drug, and thus you can expect good results with each new cycle.

Beginners should also be cautious when taking clen for the first time, starting on a smaller dose (20-40mcg) and increasing the dose slowly as their body adapts. If you’re experiencing side effects, do NOT up your dose; as this will only exacerbate the effects.

Summary on Clenbuterol

Clenbuterol, when used correctly, can be a very effective fat burner. In regards to the side effects, it’d be best to to get a check-up by your doctor to make sure you’re in good health; and then to be monitored throughout your cycle to make sure your blood pressure is within a normal range.

Also, for maximum results, users may need to make lifestyle changes; such as eating healthy, doing regular cardio and getting adequate rest.

It’s very important to follow the dosage instructions when taking clenbuterol, as it’s a powerful compound and shouldn’t be taken lightly.

In conclusion, when you add clenbuterol to your workout regime – you’ll enhance fat loss and increase the chances of achieving a leaner body. Muscle gains shouldn’t be expected, however clen may help to prevent muscle loss when eating in a calorie deficit.

clenbutrol supplement advert


See all references







Clenbuterol Cycle






Llewellyn, William (2011), Anabolics. Jupiter, FL: Molecular Nutrition. pp. 899-904.

Clenbuterol Diet Plan







Llewellyn, William (2011), Anabolics. Jupiter, FL: Molecular Nutrition. pp. 899-904.

Clenbuterol for Bodybuilders






Clenbuterol for Women







Llewellyn, William (2011), Anabolics. Jupiter, FL: Molecular Nutrition. pp. 376-386, 899-904.

O’Connor M.D, Thomas (2018), America on Steroids: A Time to Heal. Cheshire, CT: Metabolic Promotion LLC. pp. 23-25.

Image credit: Zoe-Lee Photography


Llewellyn, William (2011), Anabolics. Jupiter, FL: Molecular Nutrition. pp. 899-904.

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Ernst Peibst

Ernst Peibst has spent over 3,000 hours researching anabolic steroids and PED's. He's also dedicated the last 7 years educating people about their effects, with hundreds of thousands of people reading his articles. He's studied countless science papers, read several expert books and has consulted some of the finest doctors in the world - on the topic of steroids.

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