Clenbuterol hydrochloride is an anti-asthma medication that belongs to a broad group of drugs knows as sympathomimetics. These drugs affect that sympathetic nervous system in a wide number of ways, largely mediated by the distribution of adrenoceptors. There are actually nine different types of these receptors in the body, which are classified as either alpha or beta and further subcategorized by type number. Depending on the specific affinities of these agents for the various receptors, they can potentially be used in the treatment of conditions such as asthma, hypertension, cardiovascular shock, arrhythmias, migraine headaches and anaphylactic shock. The text Goodman and Gillman’s The Pharmacological Basis of Therapeutics 9th edition does a good job of describing the diverse nature in which these drugs affect the body: Most of the actions of catecholamines and sympathomimetic agents can be classified into seven broad types: (1) peripheral excitatory action on certain types of smooth muscles such as those in blood vessels supplying the skin, kidney, and mucous membranes, and on the gland cells, such as those of the salivary and sweat glands; (2) a peripheral inhibitory action on certain other types of smooth muscle, such as those in the wall of the gut, in the bronchial tree, and in blood vessels supplying skeletal muscle; (3) a cardiac excitatory action, responsible for an increase in heart rate and force of contraction; (4) metabolic actions, such as an increase in the rate of glycogenolysis in liver and muscle and liberation of free fatty acids from adipose tissue; (5) endocrine actions, such as modulation of the secretion of insulin, rennin, and pituitary hormones; (6) CNS actions, such as respiratory stimulation and, with some of the drugs, an increase in wakefulness and psychomotor activity and a reduction in appetite; and (7) presynaptic actions that result in either inhibition or facilitation of the release of the neurotransmitters such as such as norepinephrine and acetylcholine. Clenbuterol hydrochloride is specifically a selective beta-2 sympathomimetic, primarily affecting only one of the three subsets of beta-receptors. Of particular interest is the fact that this drug has little beta-1 stimulating activity. Since beta-1 receptors are closely tied to the cardiac effects of these agents, this allows clenbuterol hydrochloride to reduce reversible airway obstruction (an effect of beta-2 stimulation) with much less cardiovascular side effects compared to non-selective beta agonists. Clinical studies with this drug show it is extremely effective as a bronchodilator, with a low level of user complaints and high patient compliance . Clenbuterol hydrochloride also exhibits an extremely long half-life in the body, which is measured to be approximately 34 hours long . This makes steady blood levels easy to achieve, requiring only a single or twice daily dosing schedule at most . This of course makes it much easier for the patient to use, and may tie in to its high compliance rate. In animal studies clenbuterol hydrochloride is shown to exhibit anabolic activity, obviously an attractive trait to a bodybuilder or athlete. This compound is additionally a known thermogenic , with beta-2 agonists like clenbuterol hydrochloride shown to directly stimulate thermogenic , with beta-2 agonists like clenbuterol hydrochloride shown to directly stimulate fat cells and accelerate the breakdown of triglycerides to form free fatty acids. Its efficacy in this area makes clenbuterol hydrochloride a very popular fat loss drug among the bodybuilding community. Those interested in this drug are often hoping it will produce a little of both benefits, promoting the loss of body fat while imparting increases in strength and muscle mass. But as was well pointed out by a review published in the August 1995 issue of Medicine and Science in Sports and Exercise, the possible anabolic results in humans are very questionable, and based only on animal data using much larger doses than would be required for bronchodilation. With such reports there has been a lot of debate as to whether or not clenbuterol hydrochloride is really anabolic in humans at all. Some seem to swear by the fact that it builds muscle, and use clenbuterol hydrochloride regularly as an off-season or adjunct anabolic. To others, the MSSE report is confirmation that athletes have wasted valuable time and money on drugs that do not build muscle. The debate over clenbuterol hydrochloride’s potential anabolic activity continues today.
|Brand name||Clenasma, Clenbuterol hydrochloride, Clenbuterol, Spiropent, Novegam, Oxyflux, Broncoterol, Monores, Contraspasmin, Ventolase|
Clenbuterol Hydrochloride History
Clenbuterol hydrochloride has been available as a bronchodilator for decades and is widely used in many parts of the world. Although it has a good safety record and approval in a wide number of other countries, this compound has never been made available for human use in the United States. The fact that there are a number of similar effective asthma medications already approved by the FDA and available may have something to do with this, as a prospective drug firm would likely not find it a profitable enough product to warrant undergoing the expense of the new drug approval process. Regardless of this fact, foreign clenbuterol hydrochloride preparations are popular among U.S. bodybuilders and athletes, and today are widely available on the black market. Note that in recent years, clenbuterol overdose/poisoning has been reported in a number of people, striking up a great deal of controversy about the safety of this drug and its off-label use for physique- and performanceenhancing purposes.
How is Clenbuterol Hydrochloride Supplied
Clenbuterol hydrochloride is most commonly supplied in oral tablets of 20mcg each. It is also supplied in oral syrups, injectable solutions, and for inhalation use
Structural Characteristics of Clenbuterol Hydrochloride
Clenbuterol hydrochloride is a long-acting selective‚ 2- adrenergic receptor agonist. It has the chemical designation 1-(4-amino-3,5-dichloro-phenyl)-2-(tertbutylamino) ethanol.
Clenbuterol Hydrochloride Side Effects
The possible side effects of clenbuterol hydrochloride include those of other CNS stimulants, and include such occurrences as shaky hands, insomnia, sweating, increased blood pressure, and nausea. These side effects will generally subside after a week or so of use, once the user becomes accustomed to the drug. Clenbuterol hydrochloride is a CNS stimulant with potential for fatal overdose. Signs of overdose may include rapid breathing, blood pressure irregularities, irregular heartbeat, unconsciousness, trembling, shaking, panic, extreme restlessness, and severe nausea, vomiting, or diarrhea.
Clenbuterol Hydrochloride Administration
When used for the management of asthma, the most common clinical dose for adults is 20mcg (1 tablet) twice per day. Some patients require up to 40mcg (2 tablets) twice per day.
When using the drug (off-label) for physique- or performance-enhancing purposes, bodybuilders and athletes generally tailor their dosage and cycling of this product based on personal sensitivity to its benefits and side effects. To accomplish this, one often begins a cycle by taking one or two tablets per day, and gradually increasing the dosage every third day by one half to 1 tablet until a desired dosage range is established. At peak therapy some users can tolerate as many as 6-8 tablets per day (120-160mcg). Given the potency and potential for serious side effects, however, any dosage outside of the normal therapeutic range should be approached with an even greater level of caution.
The drug will usually elevate the body temperature shortly after therapy is initiated. The rise in temperature is commonly .5 to 1 degree, sometimes a little more. This elevation is due to temperature is commonly .5 to 1 degree, sometimes a little more. This elevation is due to one’s body burning excess energy (largely from fat), and is usually not uncomfortable. The number of consecutive days clenbuterol hydrochloride is now used is usually dependent on the response of the individual.To be clear, the athletic benefits of this drug will only last for a limited time and then diminish, largely due to beta-receptor downregulation. By most accounts clenbuterol hydrochloride seems to work well for approximately 4 to 6 weeks. During this period, users generally monitor their body temperature on a regular basis. We are given some level of assurance that clenbuterol hydrochloride is working by the temperature elevation. Once the temperature drops back to normal, receptor downregulation has probably diminished the efficacy of the drug. At this point increasing the dosage is usually not regarded as effective, and instead clenbuterol hydrochloride is discontinued for a period of no less than 4-6 weeks.
Many bodybuilding competitors enhance the fat burning effect of clenbuterol hydrochloride with the use of additional substances. Many have commented that when the drug is combined with thyroid hormones, specifically the powerful Cytomel, the thermogenic effect can become extremely dramatic. Such a mix is often further used during a steroid cycle, helping the individual elicit a much more toned physique from the drugs. A clenbuterol/thyroid mix is also common when using growth hormone, which is believed to enhance the thermogenic and anabolic effect of HGH therapy. Lastly, ketotifen has also been a popular adjunct to clenbuterol hydrochloride, which is an antihistamine that upregulates beta-2 receptor density. It seems capable of not only increasing the potency of each dose of clenbuterol hydrochloride (allowing the user to take less clenbuterol), but also of perhaps even slowing receptor downregulation (see the Ketotifen profile for a more comprehensive discussion).
Clenbuterol Hydrochloride Availability
Clenbuterol hydrochloride is readily available on the international market. Although it is usually a very cheap drug in common source countries, allowing black market dealers ample opportunity to obtain legitimate drugs to divert for sale, clenbuterol hydrochloride has been the subject of low-level counterfeiting. A few things are important to note:
Clenbuterol hydrochloride is not produced in the U.S., so avoid anything bearing a U.S. company name.
Clenbuterol hydrochloride should only be trusted when found with a proper brand name from a foreign drug maker. Spiropent, Novegam and Oxyflux from Mexico are the most common products in the U.S.
From Europe, the brand names of Spiropent, Broncoterol, Clenasma, Monores, Contraspasmin and Ventolase are popular.
Bulgarian clenbuterol hydrochloride is also found commonly, but so are counterfeits. This is a slightly higher risk item.
Magnus Pharmaceuticals makes the product Clenbuterol primarily for the EU and UK markets. Due to fake products appearing on the market, Magnus offers an online checker that lets steroid users verify their product originality.
Clenbuterol is a quite strong anti-catabolic / thermalgenic drug that is not a steroid. During dieting periods, or post steroid cycles, this drug has reported dramatic effects on body composition. Since it suppresses the muscle wasting effects of cortisol/cortisone, a slight increase in total muscle protein synthesis was seen. When stacked with steroids the effect were synergistic and more profound. When used as a post-cycle drug, clenbuterol helped to maintain muscle gains after AAS were discontinued. In both cases the drug acted to reduce fat deposits by elevation of thermalgenesis. It was considered very important to all polled whom had utilized this drug to start with 1-2 tabs daily (2 on -2 off) and monitor body temperature. (Increased dosages can increase body temperature to dangerous levels) Most obtained excellent results in 4-8 weeks. Many also stacked clenbuterol with thyroid drugs and /or DNP to increase the rate of calorie expenditure.
Headaches, high blood pressure, and elevated body temperature were among noted side effects. Many reported side effects after 8-12 days. The body quickly adapts to clenbuterol so "on/off" periods were a must for successful results. By alternating between E/C (Ephedrine and caffeine) stacks and Clenbuterol, the effective period was extended and results increased. Rotations weekly such as clenbuterol, week #1, ephedrine/ caffeine week# 2, seem to have brought superior results.
The reason clenbuterol begins to lose effectiveness after only 2 weeks is that the beta-2-receptors it interacts with are quite sensitive. (These are adrenalgenic receptors) Once these receptors are over stimulated for a prolonged period of time they become insensitive. Oddly enough it appears that DNP and thyroid hormones help regenerate adrenalgenic receptor function.
Since Clenbuterol dilates blood vessels in skeletal muscle but relaxes smooth muscle blood vessels, the physical reactions are quite similar to the body's own epinephrine and can effect heart rate. It also reduces the level of the amino acid taurine in the heart which stabilizes cardiac rhythms, or the electrical activity in the heart. Increased intake for taurine during use was noted as wise.
Most bodybuilders don't realize that the anabolic effects of Clenbuterol are not due to increased anabolic activity. Clenbuterol is actually effective through a different mechanism. It decreases both protein synthesis and break down. The reason anticatabolic effects result is simply because it hinders protein break down more which shifts the ratio in favor of anabolism. This means that clenbuterol had significant anti-catabolic effects when stacked with a cortisol inhibitor post or during AAS cycles. Cytadren was an often noted example. Again, since clenbuterol increases thermalgenesis, (calories released as heat) the common use of thyroid T-3 or T-4 in a stack with it caused a significant increase in body temperature. This was monitored closely by most.
Clenbuterol is utilized to treat asthma in several countries. The dosage for treatment is normally 20-30 mcg/d.
*A note of interest, clenbuterol loses effectiveness quickly due to decreased beta-receptors. A drug called Zaditen (Ketotifen) helps maintain beta-receptors. The most reported down side of Ketotifen was that most users experienced drowsiness.
Anabolic Steroid Guide reference
Clenbuterol is a very interesting and remarkable compound. It is not a steroid hormone but a beta-2- symphatomimetic. Clenbuterol, above all, has a strong anticatabolic effect, which means it decreases the rate at which protein is reduced in the muscle cell, consequently causing an enlargement of muscle cells. For this reason, numerous athletes use Clenbuterol after steroid treatment to balance the resulting catabolic phase and thus obtain maximum strength and muscle mass. A further aspect of Clenbuterol is its distinct fat-burning effect. Clenbuterol burns fat without dieting because it increases the body temperature slightly, forcing the body to burn fat for this process. Due to the higher body temperature Clenbuterol magnifies the effect of anabolic/androgenic steroids taken simultaneously, since the protein processing is increased. Athletes usually take 5-7 tablets, 100-140 mcg per day For women 80-100 mcg//day are usually sufficient, It is important that the athlete begin by taking only one tablet on the first day and then increasing the dosage by one tablet each of the following days until the desired maximum dosage is reached. The compound is usually taken over a period of 8-10 weeks. Since Clenbuterol is not a hormone compound it has no side effects typical of anabolic steroids. For this reason it is also liked by women. Possible side effects of Clenbuterol include restlessness, palpitations, tremor (involuntary trembling of fingers), headache, increased perspiration, insomnia, possible muscle spasms, increased blood pressure, and nausea. Note that these side effects are of a temporary nature and usually subside after 8-10 days, 70¢-$120 each.
Newbies Research Guide reference
Brand Names: Broncodil, Broncoterol, Cesbron, Clenasma, Clenbuter.Pharmachim, Contrasmina, Contraspasmina, Monores, Novegam, Oxyflux, Prontovent, Spiropent, Ventolase, Ventapulmin,
Description: 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 its effects on the stimulation of both type 2 and 3 beta-receptors. Clenbuterol is really one of body- building’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 clen- buterol, 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 con- centration 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 clen- buterol’s 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. I, personally, get worse results with clen vs. the good old ECA stack. Clenbuterol also didn’t blunt my hunger either and I ate more while taking it as well. I also seem to get much better effects out of cytomel as a fat burner as well. Even better than the ECA stack or clenbuterol. But, again, that is my personal opinion.
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.
Stacking Info: One week on, one week off might make sense, or alternately, two weeks on two weeks off makes sense but has the disadvantage of a “crash” period afterwards. You can take ephedrine after the clen to help reduce this “crash” period or at least make it more bearable for you. The two on/two off theo- ry is absolute bullshit and can’t work; read above.
Wlliam Llewellyn (2011) - Anabolics
L. Rea (2002) - Chemical Muscle Enhancement Bodybuilders Desk Reference
Anabolic Steroid Guide
Newbies Research Guide