T3 for accelerating weight loss 25. April 2010 William Davis (57) Supplementation of the thyroid hormone, T3, is an underappreciated means to lose weight. Thyroid health, in general, is extremely important for weight control, since even subtle low thyroid hormone levels can result in weight gain. The first step in achieving thyroid health is to be sure you are obtaining sufficient iodine. (See Iodine deficiency is real and Healthy people are the most iodine deficient) But, after iodine replacement has been undertaken, the next step is to consider your T3 status. I've seen T3 ignite weight loss or boost someone out of a weight loss "plateau" many times. Endocrinologists cringe at this notion of using T3. They claim that you will develop atrial fibrillation (an abnormal heart rhythm) and osteoporosis by doing this. I have yet to see this happen. Adding T3 revs up metabolic rate at low doses. The idea is to push free T3 hormone levels to the upper limit of normal, but not to the hyperthyroid range. While an occasional person feels a little "hyper" like they've had a pot of coffee, most people just feel energized, clear-headed, and happier. And weight trends down much more readily. Taking T3 by itself with no effort at weight loss generally yields only a modest weight reduction. However, T3 added to other weight reducing efforts, such as wheat elimination and exercise, accelerates the weight loss effect considerably. 5 lbs lost will likely be more like 8 to 10 lbs lost; 10 lbs lost will likely be more like 15 to 20 lbs, etc.It's also my suspicion that more and more people are developing a selective impairment of T3, making it all the more important. I believe that you and I are being exposed to something (perchlorates, bisphenol A, perflurooctanoic acid, and others?) that may be impairing the 5'-deiodinase enzyme that converts the T4 thyroid hormone to the active T3. Relative lack of T3 leads to slowed metabolism, weight gain, and depressed mood. While avoiding or removing the toxin impairing 5'-deiodinase would be ideal, until we find out how to do this, taking T3 is a second best. The tough part: Finding a prescriber for your T3.