Clenbuterol - A CNS Stimulant

By: Jeff Behar

Clenbuterol belongs to a broad group of drugs knows as sympathomimetics because of its effects on the sympathetic nervous system. Clenbuterol is specifically a selective beta-2 sympathomimetic, primarily affecting only one of the three subsets of beta-receptors.

Because Clenbuterol has little beta-1 stimulating it reduces reversible airway with much less cardiovascular side effects compared to nonselective beta agonists. This is why it is an extremely effective bronchodilator, with a low level of user complaints.

Clenbuterol - Benefits

Because I compete as a natural athlete (and it is a banned substance) I have not used the substance, however, I do have a science background and as such have read up on many bodybuilding substances such as ephedrine and clenbuterol before they were banned. As such I am very aware of the reported benefits and side effects of clenbuterol use.

Medicinally clenbuterol is typically use as an asthma cure by opening breathing pathways by increasing bronchodilation. In terms of action this drug is best likened to the now also illegal ephedrine and its legal replacement, ma huang.

Bodybuilders use clenbuterol for two primary reasons:

1. To increase metabolic speed. Clenbuterol is shown to directly stimulate fat cells and accelerate the breakdown of triglycerides to form free fatty acids.
2. Clenbuterol is also known to increase strength and endurance of muscles by allowing more efficient transportation of oxygen into cells.
In animal studies, clenbuterol is shown to exhibit anabolic activity, but a review published in the August 1995 issue of Medicine and Science in Sports and Exercise states that the possible anabolic activities in humans are very questionable, and based only on animal data using much larger doses than would be required for bronchodilation. This debate continues today, with many still using clenbuterol as a potential anabolic boost.

Thermogenic Effects

The drug works very quickly and you should see the effects almost immediately. Clenbuerol will elevate the body temperature (half of a degree or so) as a result of your body burning excess energy largely from fat. Clenbuterol should also only be used for relatively short period of time (4 to 6 weeks), because the body will adjust and get used to it (making the effect of clenbuterol negligible largely due to beta-receptor down regulation.

For strength gains, clenbuterol appears to be effective for a much shorter period of time (around 3-4 weeks).This may be due to an absence of real anabolic effect, with the strength gain seen with clenbuterol possibly due only to the stimulant properties of the drug (similar to the strength boost seen by Ephedrine users).

Side Effects

Nothing comes without some sort of a cost. Like any other CNS stimulant drug there can be side effects such as the shakes, insomnia, sweating, increased blood pressure and nausea. These side effects will generally subside after a week or so of use however, as your body becomes accustomed to the drug. You should still check with a doctor before using any CNS stimulant

The actual effects of long-term clenbuterol intake on performance, muscle power, and overall health have been unclear.

Minimizing Side Effects

So, to minimize negative effects and to optimize the benefits you should tailor your dosage based on your body's reaction. It is also recommended that you cycle on and off to increase effectiveness. Many competitors also find the fat burning effect of clenbuterol can be further enhanced by additional substances such as Zaditen?, Synthroid? or the powerful thyroid hormone Cytomel?.

This makes the thermogenic effect extremely dramatic. This can be to a point that the athlete could shred exceptional amounts of extra fat during contest preparations, without a dramatic restriction in calories. Such a mix can be further used during a steroid cycle, eliciting a much harder look from the anabolics.

These cutting agents can often greatly inhibit extra fat storage during the cycle, even when using strong aromatizing androgens such as many of the testosterones. A clenbuterol/thyroid mix is also common when using growth hormone, further enhancing the thermogenic and anabolic effect of such drug use.

Proper Dosage

Although I am not a doctor I have heard that the proper dosages are 80-120 mcg a day for 3 to 6 weeks. This will vary based on your goals, and your metabolism. Your best bet is to start slow, watch your core body temperature and slowly ramp up.

You should also cycle down at the 4 to 6 week mark or when your body temperature drops back to normal which would indicate that clenbuterol is no longer exhibiting a thermogenic effect. Then you should take a break for at least a few weeks before starting a new cycle.

Your Other Questions

How is it best to take clenbuterol .i.e. all in the morning before breakfast or is it better to split the dose? Also should you take it with food or on an empty stomach?

Clenbuterol exhibits an extremely long half-life in the body (approximately 34 hours) which makes steady blood levels easy to achieve, requiring only a single or twice daily dosing schedule. However, my advice is to follow the directions on the package.

Note: there are many theories of how to best take the drug and none are proven. For instance I have already discussed the 3 to 6 week cycle theory that many use. Others have found success by taking it 2 days on 2 days off, but that theory has been proven to be less productive than the other theories. Till others say that the best way to take this drug is 1 week on, 1 week off, or 2 weeks on, 2 weeks off. So, my suggestion is that you find out what works best for you

Also can you maintain your current calorie intake or shall I cut back and increase the cardio? (I want to lose a little body fat but lose no muscle)?

This depends on several factors, such as how quickly do you want to lose the excess weight. The best approach is to increase your protein, add BCAAs, GH factors and aminos to your regimen before and after your workouts.

Consider also using HMB, which has anticatobolic effects during calorie restricted diets. I have also noticed that you get the most out of anticatobolic and muscle building supplementation if taken 30 to 45 minutes before and after training.

In addition, you should consume 30 to 50 grams of high quality whey protein and 30 to 50 grams of high quality complex carbs approx. 30 to 45 minutes post workout (30 to 40 grams if under 200lbs and 40 to 50 grams if over 200lbs since it is difficult for the body to utilize much more than 50 grams in one sitting and the excess will possibly be stored as fat).

Is it much better than taking Vasopro ephedrine with SAN Tight or Ansi thermo hydroxadrine?

I am unaware of how Vasopro ephedrine with SAN Tight or Ansi thermo hydroxadrine stacks up.

Can Clenbuterol use cause increased heart muscle growth?

I am unaware of any proof that clenbuterol causes increased heart muscle growth, however I have heard that steroid use and GH can have such an effect. Many bodybuilders stack clenbuterol with their steroid and GH cycles and also use clenbuterol to blocks the cortisone receptor so they can maintain a large portion of the strength and muscle mass built up by the steroids.

Caution Should Be Used

Because of the effects on blood pressure it's best to start with low dosages (such as 20-40 ?g per day) and slowly work your way up to a maximum dosage of 80-160 ?g. You should also be aware that clenbuterol can effect your liver and that any drug can be hazardous if certain unknown preconditions exist. Please consult a physician before using any drug, including clenbuterol.

Conclusion

I am providing information and education in the hope that it assists you with being safe. Please do not consider the information I have provided you as an endorsement of clenbuterol use or as a statement of facts. There are many variables that will affect drug use, drug interaction and health effects. Again, I must stress that consult a physician before using any drug, including clenbuterol.