When T4 is converted into T3 in the body, part of rT3 is also converted. rT3 is also known as reverse T3, only from the literal meaning, it can be seen that it plays the opposite role with T3. T3 increases metabolism and burns fat, so rT3's likely role is to slow metabolism and conserve fat.
In fact, rT3 does this. In the process of losing weight, most of the need to control the intake of calories, so dieters will feel hungry most of the day. We often think that the less we eat, the faster our weight loss process will go. Actually, it's not.
During times of perceived hunger, the body produces more rT3 to reduce metabolism and maintain the body's energy stores. So doctors will tell you that you can't blindly diet in order to lose weight, long-term low-calorie diet, will reduce the body's overall metabolic level, making stubborn fat more difficult to lose. The correct way to lose weight should be to eat enough calories and adhere to exercise, improve the overall metabolic level of the body, scientific and healthy weight loss.
Similarly, when stress increases, the production of rT3 also increases, which may be one reason why some people gain weight despite increased stress.
In contrast to rT3, T3 increases overall metabolism and, with exercise, burns a lot of fat. At the same time, T3 significantly enhances skeletal muscle strength, contractility and endurance, enhances protein synthesis, and promotes muscle growth. supplements are ideal for bodybuilder use.
So, if I convert T3 directly instead of T4 to T3, can I avoid the generation of rT3?
In theory, this is exactly the right thing to do.
However, the effect of T3 is more direct, the effect will be more intense, and the possibility of side effects will be relatively greater. rT3 itself is inactive, but it competes with T3 for receptors, making it unable to bind to the corresponding receptor and thus unable to function. This can counteract some of the effect of T3, making the effect of T3 less strong. In some tissues that don't need a lot of T3, rT3 actually acts as a protective tissue. Therefore, T4 is still the safer choice. Of course, you can also choose a combination of T3 and T4.