Is available in 10 - 20 mcg tablets or in the .016 mg/gram Ventapulmin Vet variety. Clenbuterol is known as a sympathomimetic. These hormones are taken to mimic adrenaline and noradrenaline in the human body. Clenbuterol is a selective beta-2 agonist that is used to stimulate the beta receptors in fat and muscle tissue in the body. Clenbuterol exhibits most of it's effects on the stimulation of both type 2 and 3 beta receptors. Clenbuterol is really one of bodybuilding's most misunderstood performance enhancement drugs. It is true that it is effective in helping to burn bodyfat but it is often been stated that clenbuterol is effective in causing anabolic gains and has in times even been compared to some of the weaker anabolic steroids. Books such as the World Anabolic Review, 1996, by P. Grunding and M. Bachmann state incorrectly that, "its effects, however, can by all means be compared to those of steroids. Similar to a combination of Winstrol Depot and Oxandrolone...." These statements are inaccurate and misleading to say the least. A lot of these claims as to the anabolic effects of clenbuterol are derived from studying the effects of clenbuterol on livestock. Clenbuterol is effective in increasing muscle mass and decreasing fat loss in animals.

The problem with the variation in anabolic effects between humans and livestock is that livestock have an abundance of the type 3 beta receptors whereas humans have little if any of the type 3 beta receptors. These beta-3 receptors increases insulin secretion and sensitivity, causing more glucose and amino acids to be transported into skeletal muscle thus causing the anabolic effects that we, humans, just aren't seeing. As Dan Duchaine stated in his Muscle Media article on clenbuterol, "In those animal research studies showing an anabolic effect from clenbuterol, it's my guess the anabolism happens specifically when the beta2 receptor stops working. At that point, the beta3 increases and causes the anabolic effect through insulin mechanisms." Since humans, again, have either very little or no beta-3 receptors, there is no chance of this anabolic effect. Just another of the studies where everyone assumed that what works in animals must work in humans. This is just simply not the case with clenbuterol.

Clenbuterol does work effectively as a fat burner though. It does this by slight increases in the body temperature. With each degree that the temperature in your body is raised from the use of clenbuterol, you will burn up approximately an extra 5% of maintenance calories. This makes it effective as a fat burner. Your body will fight this by cutting down on the amount of active thyroid in the body as well as through beta receptor down regulation which explains why you only have a limited effective period to take clenbuterol. While I am on the subject of beta receptor down regulation, I would like to dispose of another myth. This involves the two on/two off cycling theory that I believe was originated by Bill Phillips in the Anabolic Reference Guide and has somehow made it's was into every other steroid book since then including the WAR and Physical Enhancement with an Edge. The two on-two off theory simply will not work because of one main reason: the half life of clenbuterol. This 2-on/2-off idea was a THEORY ONLY, not by a doctor or scientist, and not based on specific knowledge of clenbuterol, but derived by imitation from other drug's with shorter half lives. Clenbuterol has been reported as having a half life of about 2 days, but that is not actually correct, since it has biphasic elimination, with the half-life of the rapid phase being about 10 hours, and the slower phase being several days. Supposedly, this is one of the reasons the FDA never approved clenbuterol as an anti-asthmatic drug...the FDA frowns on drugs with long half-lives if drugs with more normal half-lives are available. So with a 2-on/2-off cycle you never have time to get enough of the clenbuterol out of your system for this theory to be reasonable. In actuality, it probably hasn't even dropped to 50% of your peak concentration before you are taking the drug again. With this all taken into account, there is no reason to think that this cycling would significantly reduce the problem of receptor desensitization. A more reasonable approach would be either one week on, one week off, or alternately, two weeks on two weeks off. The two week cycle has the disadvantage of a "crash" period afterwards. This crash period can be helped with the use of ephedrine to lessen the lethargy that you will experience.

If you are interested in taking clenbuterol for anything other than fat loss then you might as well stay away from this compound. There is a lot of talk as to how clenbuterol compares to ephedrine as well. Most "experts" feel that clen gives a better bang for the buck than the ECA stack. It should be noted that clenbuterols results and effects are much shorter lived. They work through very similar mechanisms. Both products stimulate the beta-receptors but clenbuterol seems to be a more refined version, called a second generation beta-agonist drug, than ephedrine. Clenbuterol targets the proper receptors, being the beta-2 and 3 receptors than ephedrine more specifically which should in theory make clenbuterol more effective of a fat burner. Again, most of the so called "experts" say that clenbuterol is more effective than ephedrine.

Effective Dose
80-140 mcgs. / day in split doses throughout the day. Anything over 140 mcg a day is overkill since the beta receptors can only take so much of a product and then more is just wasteful.

Source: steroidtips.com