Reverse T3: Side Effects of T3-only (or why you need T4 too)

High reverse T3 (rT3) is a “bad” thing, according to some, because rT3 “blocks” the receptors, keeping T3 out.  Therefore, high doses of T3 should be taken to “clear” rT3, and because rT3 is made from T4, no T4 should be taken.  I tend to have high reverse T3, did not do well on high doses of T3, and wanted to know if the T3-only protocol to clear rT3 had any scientific merit.  In my opinion, it does not.  The T3-only protocol may work for some, but not because it clears blocked receptors.  There are also side effects from taking such high doses of T3 that are never disclosed.  This reverse T3 page was originally one long page with 11 sections that summarized my research.  The 11 sections have now been broken down into individual posts, to make the material easier to access.  To fully understand the material, it should be read in its entirety, ending with the conclusion.  To read only one portion takes it out of context.  There are over 70 references that substantiate everything said, and I highly recommend further reading by anyone considering the protocol.

The T3-only protocol is not for everyone, and some people have had serious side effects.  Inability to think and remember anything (dementia), severe hair loss, muscle wasting, bone loss (osteoporosis), and high blood sugar (diabetes) are just a few of the side effects.  T3-only side effects

Yet other patients claim this protocol gave them their lives back.  How is that possible?  Different biochemistries require different proportions of T3 and T4.  Optimal thyroid dosing

What exactly is the T3-only protocol?  Reverse T3 and the “T3-only” protocol

Estradiol and SHBG rise to unnatural levels on the T3-only protocol.  T3’s negative effect on other hormones

Who made this up?  Are they benefiting financially?  The cost of compounded T3 far exceeds the cost of generic T4 or desiccated thyroid.  The reverse T3 ratio is a nonsensical number because it can be low for several different reasons, each requiring a different treatment.

Does reverse T3 have a purpose?  Yes it does!  Reverse T3’s role in the body

Reverse T3 is made under certain medical conditions by the D3 deiodinase enzyme. D3, the deiodinase enzyme that makes reverse T3 (NOT Vitamin D3)

T4 is used by many cells in the body, especially hair; it is more than a prohormone and there are indeed T4 receptors.  T4’s role in the body

The brain needs ample T4 to function properly and high levels of T3 cause brain dysfunction.  T3 and T4’s role in the brain

Hyperthyroid patients have the highest levels of rT3.  If rT3 really blocked the receptors, no one would ever be hyperthyroid.  Think about it.  Do thyroid receptors really get blocked and take 12 weeks to clear?  Is T4 really the problem?

Still questioning the reverse T3 theory and T3-only protocol?  Whom to believe?  Thyroid internet forums