L-Thyroxin 100 tabs (100 mcg/1 tab)

L-Thyroxin by Berlin-Chemie is the main hormone of the thyroid gland. Thyroxin is used in medicine to treat hypothyroidism (low thyroid hormone levels), in bodybuilding mainly as a means for weight loss, but also to compensate for hypothyroidism during the use of growth hormone.

What is the difference between T3 and T4

The thyroid gland secretes mainly T4 (thyroxine) - which in peripheral tissues is converted into a more active form T3 (triiodothyronine) by the enzyme selenium-dependent monodeiodinase. Thus, T4 can be considered a prohormone. Detailed description here.

Many resources list triiodothyronine as the best choice, however scientific data suggests otherwise. Quote from Goodman's Clinical Pharmacology, latest 12th edition, 2010 - the most authoritative book on pharmacology in the world:

Liothyronine is less desirable for chronic replacement therapy due to the requirement for more frequent dosing (plasma t1/2 = 0.75 days), higher cost, and transient elevations of serum T3 concentrations above the normal range. In addition, organs that express the type 2 deiodinase use the locally generated T3 in addition to plasma T3, and hence there is theoretical concern that these organs will not maintain physiological intracellular T3 levels in the absence of plasma T4.

So we get:

• T3 is noticeably more expensive;
• T3 creates unwanted fluctuations in concentration;
• Tissues with type 2 deiodinase also use triiodothyronine, formed from T4 inside the cell. This means that the intracellular level of T3 in these tissues will be lower even if the concentration of thyroxine remains unchanged (and when taking a fat-burning drug, it will be below normal). From any source you can find out that type 2 deiodinase is synthesized in adipose tissue;
• Athletes report that T4 has less of a destructive effect on muscles;
• 25-100 mcg/day T3 is equivalent to ≈300 mcg/day T4.

From the above arguments, it follows that thyroxine is preferable for fat burning, at least by three criteria. In rare cases, T4 shows low efficiency because the level of its conversion to T3 decreases against the background of a low-carbohydrate diet.

Effects of taking L-Thyroxine

1. acceleration of metabolism;
2. increased heat production;
3. fat burning;
4. stimulating effect on the central nervous system;
5. appetite suppression;
6. decreased need for sleep;
7. increasing physical performance.

Medical indications for taking L-Thyroxine

• benign goiter with euthyroid state of thyroid function;
• prevention of goiter recurrence after goiter resection with euthyroid thyroid function;
• replacement therapy for hypothyroidism of various etiologies;
• adjuvant for thyreostatic therapy of hyperthyroidism after achieving a euthyroid functional state;
• suppressive and replacement therapy of thyroid cancer, mainly after thyroidectomy.

L-Thyroxine for weight loss

Many women and bodybuilders resort to using Thyroxine as a weight loss product. Thyroxine has a powerful fat burning effect, increases calorie expenditure and speeds up metabolism. Its popularity has decreased recently due to its negative impact on the heart, thyroxine has an adrenaline-like effect, causing the heart to beat faster, and at the same time causes a feeling of excitement and anxiety, which are not very well tolerated. However, many side effects can be eliminated by combining thyroxine and beta blockers. Beta blockers inhibit the receptors through which thyroxine affects the heart, thus, they prevent the negative impact of thyroxine on the heart, normalize the rhythm and reduce the manifestation of some other side effects of thyroxine.

Many people believe that thyroxine can irreversibly suppress the function of one's own thyroid gland, but studies have shown that even large doses of the drug reduce the secretion of one's own hormones by only 20% over 3 weeks of use, and after 4 weeks the secretion returned to normal.

Advantages of thyroxine: high availability and effectiveness. Disadvantages of thyroxine: quite a large number of side effects, but many of them can be prevented.

Exogenous thyroxine can cause artificial thyrotoxicosis. In this case, unlike true hyperfunction of the thyroid gland, the level of thyroglobulin (TG) will be reduced.

L-Thyroxine Usage and Dosage

• start taking thyroxine with 50 mcg per day, 2 times a day (25 mcg) in the first half of the day. In the morning, take 25 mg of metoprolol (a beta blocker that eliminates heart overload and palpitations), if the pulse rate after lunch is higher than 70 beats per minute at rest, then take another 25 mg of metoprolol;
• gradually increase the dose to 150-300 mcg per day, 3 times a day until 18:00. Increase the daily dose of Metoprolol to 100 mg (2 times a day, 50 mg). The dosage of metoprolol is selected individually so that the resting pulse rate is 60-70 beats per minute;
• reduce the dose of thyroxine if severe side effects occur;
• monitor your heart rate, if your resting heart rate is above 80, increase the dose of metoprolol by 25 mg, if your resting heart rate is below 60 beats per minute, reduce the dose of metoprolol by 25 mg;
• Monitor your blood pressure, it should not be higher than 140/90 mm Hg. Metoprolol helps to lower blood pressure;
• course duration 4-7 weeks;
• Do not stop taking thyroxine abruptly: start reducing the dose 2 weeks before the end of the cycle, continue gradually reducing until complete withdrawal;
• If you have diarrhea, include loperamide in the course, 1-2 capsules per day.
• minimum break after completion of the course is 3-4 weeks;
• If you feel heaviness in the heart area, it is better to add Asparkam in addition to Metoprolol. 4-6 tablets per day, divided into 2-3 doses, after meals. It will also not be superfluous to improve the heart function with Riboxin. 2-4 tablets at a time, 2-3 times a day. Riboxin will improve the energy balance of the myocardium, and Asparkam will become a source of Potassium and Magnesium, necessary for maintaining a normal heart rhythm.

Side effects

• tachycardia (palpitations), increased blood pressure - eliminated by beta-blockers;
• osteoporosis;
• diarrhea - eliminated by loperamide;
• agitation;
• insomnia;
• muscle tremors;
• dry mouth;
• sweating;
• feeling of heat;
• decreased thyroid function (occurs with long courses and very high doses of thyroxine; when using recommended doses, the function is restored within 3-4 weeks);
• allergic rash.

A detailed description of side effects can be found in the instructions. A specialist consultation is also necessary to identify contraindications.

Features of application

Before initiating thyroid hormone therapy or performing thyroid suppression tests, the following diseases or conditions should be ruled out or treated:

• ischemic heart disease;
• angina pectoris;
• hypertension;
• pituitary and/or adrenal cortex insufficiency.

Thyroid autonomy should also be excluded or treated before initiating thyroid hormone treatment.