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  • Anonymous
      Post count: 93172

      Here, Taskit, is the short-course (amateur style) on these hormones.

      The thyroid produces two main hormones, identified by the number of iodine atoms in them as T4 and T3, in a proportion of approximately 4:1. The T3 hormone is the one that the cells use for metabolism. There are a variety of places in the body (the liver and kidneys being two of the major ones), where the T4 is naturally converted to T3 after leaving the thyroid, as the body needs it.

      When it comes to thyroid replacement hormone treatment, the standard treatment is to give only T4. Why? Well, first there’s the fact that the body naturally converts it to T3 as needed. Secondly, T3 is monumentally more potent than T4 AND has a very short life span, so it is much more difficult to regulate the dosage, and there are more potential negative side effects. (Specifically, T4’s half-life in the body is 6.7 days, whereas T3’s half life is 0.75 days.) There are some folks for which the standard T4 treatment does not seem to work well, for whatever reason, so there are a variety of thyroid hormone replacement products available for the doctors to prescribe.

      The first hormone replacement products were, and still are, made from grinding up pork and beef thyroids. These include Armour Thyroid, Thyroid Strong,Thyrar, and SPT. According to The Pill Book “These were effective but lacked standardization, which made it difficult for some doctors to control their patients’ thyroid condition.”

      Then, the man-made (synthetic) hormones were developed. They are chemically identical to the naturally occurring hormones. It is much easier to standardize the dose contained in each pill, so doctors have begun to prescribe them the most.

      The T4 replacement hormone (levothyroxine sodium) is available under the brand names Levothyroid, Levoxyl, Synthroid, and Levoxine.

      Cytomel is straight T3 (generic name liothyronine sodium) . It is possible, although difficult I understand, to get a time-release form of cytomel as well.

      There is a combination T4/T3 product (generic name liotrix) available under the brand names Euthroid and Thyrolar. This contains the 4:1, naturally occurring proportions of the hormones.

      I hope this helps.


        Post count: 93172

        Bobbi’s post is exactly the kind that needs it’s number written down for later easy reference
        and retrival. It is Post # 9791 and could be retrived by that number.

        Jake’s eye surgery post, referenced by Bobbi earlier today, is # 184.

          Post count: 93172

          Great respose, Bobbi!
          I’d just like to clarify your comment that T4 is converted to T3 as the
          body needs it. There is no guarantee that this is happening AT ALL!
          No one is testing whether you have the enzyme, deiodinase, that does this.
          The current means of thyroid testing takes into account only TSH values
          that will be normal if T4, synthroid, is given. I know because this is
          happening to me, and I still have no medical people who believe me.
          It is my belief that T4 is totally biologically inactive and MUST be
          converted to T3, the active hormone. I spent ten years in hell on synthroid
          which was doing nothing in my body.
          I should repeat that we cannot live without T3. It is the hormone which
          unwinds the DNA so that every chemical in your body can be replicated and
          is absolutely essential to life! And no doubt the cause of our vast
          array of symptoms.
          Better, but still not okay on Armour thyroid.

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