Written by Carlon M. Colker, MD
09 September 2006

Extreme Muscle Enhancement

By Carlon M. Colker, MD




Clenbuterol is a stimulant drug prescribed outside the United States for asthmatics. In some ways, it works like ephedrine as a "beta-2 agonist" (i.e., dilates the airways and reduces constrictive wheezing). However, unlike ephedrine (which is out of the body in a few hours) the stimulant (six- to eight-hour maximum peak effect) and thermogenic (fat burning) qualities of the drug can last for many hours and even days, without actually interfering much with the normal sleep-wake cycle. But this is just one small facet of a drug that has rapidly become a mainstay in the arsenal of the professional physique competitor and athlete alike.


Chick Magnet

Bodybuilders have developed a particular penchant for clenbuterol because it has the rare and perhaps unique feature of being able to go beyond mild mass sparing and into the realm of significant, anti-catabolic tissue building, all while incinerating fat. In other words, it helps you lose the jelly rolls while also helping just a little with size and fullness- without going overboard.

For quite a few years now, clenbuterol has been the drug of choice, especially among fitness chicks. I remember how they would all grub for "clen" around the gym. I mean coast to coast, at nearly every hardcore gym where I'd train, these chicks were like little junkies (and so many still are). Showing them some clen was like showing crack to a crackhead. I've known guys who traded clen for locker room oral sex from fitness piggies. Imagine that. I mean talk about strung out! But that's the way it was and that's the power of the drug. Chicks will bend over backward for it ... literally. I mean some dealers would show up at the gym, open up the back of their cars and make more money peddling clenbuterol to the chickees than juice to the meatheads! It was unreal.

It's not a lot different today, though it's all under wraps. Now it's like a dirty little secret among the pro fitness chicks and physique competitors. But the truth remains that it's more popular then ever, albeit much harder to obtain.


No Monster Mass Gains

Of course, it's not just the chickees. There are plenty of strung out male bodybuilders as well. But clenbuterol interestingly seems to have a more variable effect from one male to another. Unlike females, who almost invariably respond to the fat-burning effects of the drug regardless of body type, it's simply not the same for men. I've found it tends to be a little too anorectic in the male ectomorph. In the male endomorph, the results are often never realized. The male mesomorph seems to be perfectly suited to receiving all of the ergogenic effects. This includes cuts, as well as mass gain (anabolism).

In fact, in the right male subject, clenbuterol has marked anabolic effects. It slightly increases muscle mass and protein content, while dramatically decreasing fat deposition. Research tells us that clenbuterol increases muscle wet weight, but not protein density, in predominantly fast-twitch muscles (e.g., quadriceps) and increases protein density, but not wet weight, in predominantly slow-twitch muscles (e.g., calves). This suggests that the mechanisms for regulating muscle growth may produce more size in the fast-twitch muscles and more recovery ability in the slow-twitch fibers. But even though clenbuterol can be surprisingly anabolic in the right subjects, bodybuilders still don't get the monster mass gains seen with testosterone or GH. A drawback bodybuilders have figured out is that clenbuterol must be cycled on and off because of severe beta receptor down-regulation. So clenbuterol is effective for only about two to three weeks at a time before a week or more must be taken off from the drug.


Reaching a Steady-state

While traveling in Europe and the Middle East, I was astounded at how prevalent the use was among strength athletes. While the typical medical therapeutic dose in Europe among otherwise healthy adult male subjects is about 20 micrograms twice a day, typical doses of abuse for the bodybuilder, fitness competitor and athlete are 100 micrograms per day. A common sample run might start at 20 micrograms once a day for a couple of days, with doses increasing as tolerated to the optimal steady-state dosage (for some abusers, as much as 200 micrograms per day in divided doses!). Steady-state is generally reached within five days.

Once in steady-state, this dosage generally continues for about three weeks before tapering back down over another five days. After that, optimal results are achieved by resisting the temptation to continue it and instead, taking one to two weeks off from the drug. This allows the down-regulated receptor pool to regenerate itself and again become sensitive to the drug. From there, cycles are resumed every two to three weeks.

In the U.S., clenbuterol isn't an approved drug for humans. It only exists in this country in a veterinary form called Ventipulmin syrup. This product is the only FDA-approved solution for reversible respiratory problems and respiratory conditions such as allergy-induced respiratory distress, small airway disease and chronic obstructive pulmonary disease (COPD)- but in horses! It relieves reversible bronchospasm arising from a variety of respiratory conditions by easing airway muscle spasm, increasing mucus secretions for improved airway resistance and improving mucociliary transport by decreasing the thickness of mucus in these animals. Federal law restricts this drug to use only by, or on the order of, a licensed veterinarian- and only in animals.


An Altered State of Consciousness

On the animal-use front, clenbuterol has also been used by cattlemen to breed larger cattle. But reports abound in Europe of humans being grossly overexposed to clenbuterol by eating cattle that had been given clenbuterol. One report from Spain involved 113 cases of people developing nervousness, tachycardia, muscle shaking, pain and headache after eating veal liver (high-concentration sequestering occurs in the liver). Their symptoms lasted as long as six days. For this reason, it's illegal for cattlemen to give clenbuterol or any other beta agonist to cattle, and federal law prohibits the use of clenbuterol in animals intended for food. Though these people were overexposed to the drug, it seems that none of them died or suffered long-term illnesses as a result of the overexposure. Yet, even in physiologic human dose, there's a danger when not taken properly.

Not surprisingly, clenbuterol abuse has become more prevalent in young people not involved with either bodybuilding or athletics. It started in the 90s with the age of ecstasy abuse, techno clubbing and the dance-until-you-drop, altered state of consciousness. The popular physique among these young people was the shredded look. It still is today, more then ever. The ultimate desire is to be lean and shredded. So clenbuterol is gaining rapid popularity. Take ecstasy and wash it down with some Red Bull, then follow it up with some clenbuterol abuse and you and your washboard abs will be ready to thump all night with the other drones. Of course, the problem with this popular mix in the wrong person is the very real potential for cardiac arrest.

In chronic doses (i.e., continuous use for many months with no break) clenbuterol may produce myocardial hypertrophy (thickening of the wall of the heart). Ironically, this isn't always seen as a bad thing in select cases. The fact is that clenbuterol has been used in combination with left ventricular assist devices for the treatment of end-stage heart failure by reversing myocardial atrophy. The mechanism of action on these heart cells hasn't been fully elucidated. We do know that chronic and uninterrupted administration of clenbuterol causes a significant increase in the utilization of carbohydrates in the Krebs cycle at the cellular level, while inducing an increase in muscle cell calcium content.

Yet even when taken properly and assuming the risks, athletes have another problem. All beta agonists, including clenbuterol, are banned by the World Anti-Doping Agency (WADA), the International Olympic Committee (IOC) and most major sports organizations. Many athletes have abused clenbuterol to enhance performance. Athletes love it because it perks them up and gives them energy like an amphetamine rush and thus, burns fat, but without the undesirable wasting that comes along with stimulant abuse.

Clenbuterol comes in oral form in small tablets, so it's easy to take and conceal. Plus, it has the added benefit of leaving the system in a matter of days after discontinuing, thus being undetectable (usually about five days before the urine is clear). But again, that's only if athletes get away with abusing it. Major league baseball pitcher Jason Grimsley admitted using the drug, and tennis player Mariano Puerta was penalized for abuse. In the world of track and field, German sprinter Katrin Krabbe received a four-year ban for taking the drug.

As a few athletes here and there pop up under detection, just know that this is the very tip of the iceberg. Also, when compared to professional physique competitors, the comparison is laughable. Currently, there are few, if any, high-level professional male or female competitors who haven't taken clenbuterol.


Dr. Colker's book, Extreme Muscle Enhancement: Bodybuilding's Most Powerful Techniques is available by calling 1-800-310-1555 or ordering the book online at www.prosource.net.