Name: Clenbuterol
Other common names and terms: Clen
Active Life: 3 days
Drug Class: Beta 2 Sympathomitetic
Detection Time: 4 days
Common doses: Up to 140mcg per day for men / up to 100mcg per day for women
Blood pressure: Rare
Acne: No
Water retention: No
Aromatisation: None
Clenbuterol structure Clenbuterol Structure

Clenbuterol is a sympathomimetic drug which is widely used in many countries for the treatments of asthma, cardiovascular shock, hypertension and more. Clenbuterol is commonly known as "clen" and is often created in 20mcg (0.02mg) tablets, although other administrative forms are available such as injectables and liquids. Of main interest to athletes is clenbuterol's thermogenic ability, in other words, its ability to slightly raise the core temperature of the body, resulting in greater calorie outlay.

There is a risk when stacking clenbuterol (combining with other drugs or substances) from the possible cumulative result from two or more substances that stimulate the adrenergic beta 2 receptors. The resulting side effects are dependant on the dosages used, and therefore it would be unwise to use clenbuterol with ephedrine. Ephedrine is often used during the time periods when the user ceases to take clenbuterol to allow for the up-regulation of the beta 2 receptors, which ephedrine will still allow due to its weaker ability to down-regulation the receptors. Ephedrine also has a quicker half life which allows for some period of time for the receptors to recover.

Clenbuterol has possible side effects, including; tremors and cramps, nausea, anxiety, sweating, headaches and increased appetite. Clenbuterol may possibly be able to lead to cardiac hypertrophy and also hypertension, so anybody with any heart issues would be wise to avoid a stimulant such as clenbuterol. Muscular cramping can be aided by supplementing with taurine at 5 grams per day, drinking plenty of fluids to ensure you are hydrated, and by eating plenty of bananas.

Clenbuterol causes quick down-regulation of the beta 2 receptors and therefore breaks need to be taken from its usage to allow the receptors to recover. A two week on/off cycle regime often provide fruitful results, allowing sufficient time for receptor recovery in the two weeks off the clenbuterol. During this time many use ephedrine which although being a stimulant still allows for sufficient recovery due to its shorter half life and weaker abilities.

Ketotifen is an anti-histamine that is of interest to athletes that administer clenbuterol. Ketotifen inhibits the down-regulation of the receptors, hence there being less need to take a break from clenbuterol and also making a lesser dose of clenbuterol be more effective. 3-4mg of ketotifen usually is more then enough to inhibit the down-regulation of the beta receptors.

A tapering (or pyramiding) of dosage is common at the start of a clenbuterol cycle, with 20mcg taken on the first day, followed by a further 20mcg each day on the following days until a maximum dose of 140mcg is reached daily if side effects are tolerable (day 1 - 20mcg, day 2 - 40mcg, day 3 - 60mcg and so on...). Side effects often decrease with greater use of clenbuterol, but by tapering up the dose we allow for the side effects to be constricted. We would run the final dosage until a total of two weeks has past since the start of the clenbuterol cycle, and at this point we would just cease use of the clenbuterol. The second cycle of clenbuterol will start again after two weeks. Knowing your tolerance level we can now start the cycle again using 40-60mcg under that level, and building back up to the maximum dosage which we will run for the remaining two weeks. This two weeks on/off will often be continued for a maximum of 12-14 weeks.

Example clenbuterol cycle

Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7
20mcg 40mcg 60mcg 80mcg 100mcg 120mcg 140mcg
Day 8 Day 9 Day 10 Day 11 Day 12 Day 13 Day 14
140mcg 140mcg 140mcg 140mcg 140mcg 140mcg 140mcg
Day 15 Day 16 Day 17 Day 18 Day 19 Day 20 Day 21
OFF (Ephedrine / ECA cycle can be used)
Day 22 Day 23 Day 24 Day 25 Day 26 Day 27 Day 28
OFF (Ephedrine / ECA cycle can be used)
Day 29 Day 30 Day 31 Day 32 Day 33 Day 34 Day 35
80mcg 100mcg 120mcg 140mcg 140mcg 140mcg 140mcg
Day 36 Day 37 Day 38 Day 39 Day 40 Day 41 Day 42
140mcg 140mcg 140mcg 140mcg 140mcg 140mcg 140mcg
Day 43 Day 44 Day 45 Day 46 Day 47 Day 48 Day 49
OFF (Ephedrine / ECA cycle can be used)
Day 50 Day 51 Day 52 Day 53 Day 54 Day 55 Day 56
OFF (Ephedrine / ECA cycle can be used)

Clenbuterol is also said to have anti-catabolic abilities, and is often taken at low dosages (20-40mcg) during PCT to decrease possible muscle loss.

Important information

Articles about performance enhancing drugs are for informational purposes only and are not intended to encourage or promote the use of such substances. These substances should only ever be used under the advice and supervision of a qualified and licensed physician.