clenbuterol alternative

What is Clenbuterol’s Half-Life? (And Why This is Important)

Updated June 11, 2020
clenbuterol alternative
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Clenbuterol can spike your metabolism and burn fat (arguably) better than any fat burner on the planet. But what’s clenbuterol’s half life and why should you care?

The half-life of a substance is the time taken from when the drug’s first ingested, to the time where half of it remains in your body.

The half-life of a steroid is important for a bodybuilder to know for several reasons. Firstly it helps you understand how much of a substance is roughly left in your system after a period of time. This could be important when coming off a substance in time to pass a drugs test for a bodybuilding competition.

A drug’s half-life can also be an indicator on how fast you can expect results. If it’s half-life is short, this means that it’ll enter your body quickly and will also leave in a quick fashion. This is what we call a fast acting compound, and so you’ll experience fast gains.

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).

More About Clenbuterol

In bodybuilding, clenbuterol (otherwise known as clen) is a cutting agent which turbocharges fat loss. Clen has the ability to take you from gear 2 to gear 5 when it comes to getting shredded. It’s usually taken by swallowing pills or administering injections and is sold under various trade names.

Clenbuterol relaxes your smooth muscle, causing blood vessels to dilate, increasing oxygen supply to your muscles. Clen also increases the amount of adreanline your body produces which is why some users’ behaviour can be described as ‘hyper’, ‘wired’ or ‘stimulated’.

Clenbuterol stimulates the beta-2 receptor, causing a sudden increase in a person’s metabolic rate and core body temperature. With this stimulation of the beta-2 receptors, mitochondria begin to produce heat which causes your body to work harder to cool itself back down to normal (thus burning calories). With this extra calorie expenditure – weight loss is inevitable.

Weight Loss

clenbuterol results
Credit: Zoe-Lee Photography

Even though clenbuterol’s not legal to use in many countries, it’s very popular in bodybuilding as a weight loss agent. Before a competition, clenbuterol’s often used with other cutting steroids such as anavar, winstrol or testosterone.

This will enable a bodybuilder to get considerably leaner, maximizing his/her muscle definition and vascularity onstage. However, it’s not just competitive bodybuilders who use clen; guys who simply want to lose a quick 10lbs or so will often cycle clenbuterol.


For best results, you have to use clenbuterol in the correct dosages. Clenbuterol’s dosage is dependent on the sex of the person, experience, and tolerance to the drug. Men can increase the dosage up to 80 mcg if the side effects are bearable.

As for female users, the recommended starting dose is 10 mcg. Experienced female users can go up to 60 mcg per day.

How to Cycle Clen

arnold bicycle

A typical clenbuterol cycle protocol is to take it for two weeks on, followed by two weeks off. The reason behind this is that since clen saturates the beta-2 receptors, its fat burning effects diminish after a fortnight. By taking a break at this point, it allows the receptors to regulate back to their normal pre-clen state. Allowing your body to rest in this way, enables you to keep on burning fat with every cycle.

A standard clenbuterol cycle will consist of a bodybuilder using the 2 week on/2 week off protocol for about 10 weeks.

With clenbuterol, no post-cycle therapy’s needed as it’s not a steroid and thus doesn’t shut down your testosterone production. However, if you run clen in conjunction with other steroids, a post cycle therapy is necessary.

Typical Results

clenbuterol effects

Due to clenbuterol’s relatively short half-life, results come thick and fast.

However, the results of Clenbuterol vary considerably dependent on a person’s diet, cycle length, dosage, and genetics. Bodybuilders however typically lose 6-10lbs from a standard clenbuterol cycle.

Where to Purchase Clenbuterol

clenbutrol reviewAs Clen is illegal and banned for human consumption in most countries, most bodybuilders buy it on the black market (although this comes with its risks). Clen’s usually taken in different forms such as liquid or pill. Spray form is also possible, although it’s less popular.


Clenbutrol from Crazybulk is a legal alternative which is designed to mimic the effects of clen but without the side effects. This supplement is FDA approved and has received several positive reviews.





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

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