Cytomel is not an anabolic/androgenic steroid but a thyroid hormone. As a substance it contains synthetically manufactured liothyronine sodium which resembles the natural thyroid hormone tricodide-thyronine (L-T3). The thyroid of a healthy person usually produces two hormones, the better known L-thyroxine (L-T4) and the aforementioned L-trilodine~thyronine (L-T3). Since Cytomel is the synthetic equivalent of the latter hormone, it causes the same processes in the body as if the thyroid were to produce more of the hormone. It is interesting to note that L-T3 is clearly the stronger and more effective of these two hormones. This makes Cytomel more effective than the commercially available L-T4 compounds such as L-thyroxine or Synthroid. The manufacturer of the German L-T3 compound, Hoechst AG, ascribes the following characteristics to its Thybon drug, making it clear that L-T3 is superior to L-T4: “The synthetically manufactured thyroid hormone, L-trilodine-thyronine (L-T3), included in Thybon, in experimental and clinical testing has proven to be 4-5 times more biologically active and to take effect more quickly than L-thyroxine (L-T4).” In school medicine Cytomel is used to treat thyroid insufficiency (hypothyroidism). Among other secondary symptoms are obesity, metabolic disorders, and fatigue. Bodybuilders take advantage of these charcteristics and stimulate their metabolism by taking Cytomel, which causes a faster conversion of carbohydrates, proteins, and fats. Bodybuilders, of course, are especially interested in an increased lipolysis, which means increased fat burning. Competing bodybuilders, in particular, use Cytomel during the weeks before a championship since it helps to maintain an extremely low fat content, without necessitating a hunger diet. Athletes who use low dosages of Cytomel report that by the simultaneous intake of steroids, the steroids become more effective, most likely as the result of the faster conversion of protein.
Until recently, Cytomel was used by bodybuilders and female bodybuilders, in particular-on a daily basis over several months to remain “hard” and in good shape all year round. Believe us when we tell you that to a great extent several bodybuilders who are pictured in “muscle magazines” and display a hard and defined look in photos, eat fast food and iron this out by taking Cytomel. The over stimulated thyroid burns calories like a blast furnace. Nowadays, instead of Cytomel, athletes use Clenbuterol which is becoming more and more popular. Those who combine these two compounds will burn an enormous amount of fat. The next time you read that a certain pro bodybuilder approaching a championship competition is still eating 4000 calories a day, you will know why. Cytomel is also popular among female bodybuilders. Since women generally have slower metabolisms than men, it is extremely difficult for them to obtain the right form for a competition given today’s standards. A drastic reduction of food and calories below the 1000 calorie/day mark can often be avoided by taking Cytomel. Women, no doubt, are more prone to side effects than men but usually get along well with 50 mcg/day. A short-term intake of Cytomel in a reasonable dosage is certainly “healthier” than an extreme hunger diet.
As for the dosage, one should be very careful since Cytomel is a very strong and highly effective thyroid hormone. It is extremely important that one begins with a low dosage, increasing it slowly and evenly over the course of several days. Most athletes begin by taking one 20 mcg tablet per day and increasing this dosage every three to four days by one additional tablet. A dose higher than 100 mcg/ day is not necessary and not advisable. It is not recommended that the daily dose be taken all at once but broken down into three smaller individual doses so that they become more effective. It is also important that Cytomel not be taken for more than six weeks. At least two months of abstinence from the drug needs to follow. Those who take high dosages of Cytomel over a long period of time are at risk of developing a chronic thyroid insufficiency. As a consequence, the athlete might be forced to take thyroid medication for the rest of his life. It is also important that the dosage is reduced slowly and evenly by taking fewer tablets and not be ended abruptly. Those who plan to take Cytomel should first consult a physician in order to be sure that no thyroid hyper function exists.
Possible side effects such as medication are described in the package insert by the German pharmaceutical group Hoechst AG for their compound Thybon: “Exceeding the individual limits of compatibility for liothyronine or taking an overdose, especially, if the dose is increased too quickly at the beginning of the treatment, can cause the following clinical symptoms for a thyroid hyperfunction): heart palpitation, trembling, irregular heartbeat, heart oppression, agitation, shortness of breath, excretion of sugar through the urine, excessive perspiration, diarrhea, weight loss, psychic disorders, etc., as well as symptoms of hypersensitivity.” Our experience is that most symptoms consist of trembling of hands, nausea, headaches, high perspiration, and increased heartbeat. These negative side effects can often be eliminated by temporarily reducing the daily dosage. Caution, however is advised when taking Cytomel since, especially in the beginning, the effect can be quick and sometimes drastic. Athletes do not use the injectable version of L-T3, this is normally used as “emergency therapy for thyrotoxic coma.” Those who use Cytomel over several weeks will experience a decrease in muscle mass. This can be avoided or delayed by simultaneously taking steroids. For the most part, since Cytomel also metabolizes protein, the athlete must eat a diet rich in protein.
T4 has been experiencing a bit of a renaissance. This is due to it being a bit more muscle sparing, and synergy with growth hormone. Most bodybuilders use use GH for precontest dieting, and T4 has found a bit of a niche for those using GH and dieting. At this point, whether on a diet or not, T4 has become a much sought after drug for use with cutting cycles which include Growth hormone. I have even received a phone call from doctors and Hormone Replacement Clinics, who wanted more practical information on the use of GH + T4.
So, at this point, I think that most of the people in the bodybuilding world who are using T4 are using it along with their Growth Hormone for the most part.
Anecdotally, many bodybuilders feel that T4 is less harsh on muscle tissue and they’re able to maintain more muscle when dieting down by using T4, than compared with when they’ve used T3.