Sometimes, patients choose to be on T3-only (triiodothyronine) if they discover that certain problems (like low/high cortisol and/or non-optimal iron levels) are forcing conversion of T4 to too much Reverse T3…and they know it will take awhile to correct those problems. They then look at getting back on natural desiccated thyroid someday later. Others, like author and patient Paul Robinson of the UK, use T3-only because something goes quite wrong if they use any T4-containing thyroid product i.e. not just an RT3 problem.

What are brands of synthetic T3 (Liothyronine Sodium)?  Cytomel is well-known in the US and Canada, as is Cynomel in Mexico.  Other worldwide brands and names  include Tertroxin, Linomel, Cyronine, Ti-Tre, Tironina, Tiromel and Trijodthyronin. Generic T3 is available, but patients report it to be far weaker.

How do patients start on T3-only?  Since many patients will have been on natural desiccated thyroid (or the combination of synthetic T4 with synthetic T3), many simply stop taking those medications, and wait. Their goal is give a little time for the T4 to start decreasing, which in turn can lower the high RT3. The half-life of T4 is about one week, and that corresponds with the time one will start to feel the return of thyroid symptoms. And that’s where they start introducing T3-only, or right before.

Some patients have stopped NDT or the synthetic combo one day, and started on T3-only the next. But it has to be in very small amounts until the T4, and its conversion to T3, falls, before raising too much.

How do I dose my T3?  Not rigidly, as we used to think, such as every “four” hours, or every “five hours”. Being rigid like the latter can cause you to take your subsequent T3 too soon (causing an overlap) or too late (which makes you hypothyroid). It’s now more about when your signs (BP, pulse, temps) and symptoms (feeling fatigue, higher heartrate, etc) tell you it’s time to take that second dose, and third dose, etc.

If one is doing the early morning T3CM dose to bring back better adrenal function, a second and third dose might be 5 mcg (or 6.25, which is a quarter of a 25 mcg tablet), then raised as needed. Again, the timing is based on when your signs and symptoms tell you it’s time for more.

If someone isn’t doing the T3CM, they might start on 5 – 15 mcg in the morning, and another 5 – 15 mcg when one’s signs (BP, heartrate, etc) and symptoms (tiredness) dictate it.  The spread between the two will be different from individual to individual depending on how fast they metabolize the first dose, so it could be from 3 hours later to 7 hours later. Many dosing schedules based on signs and symptoms seem to fall in the 4-5 hour spread, but again, it’s totally individual. After about five days, a third dose of 5 – 15 mcg is added based on signs and symptoms. Patients seem to do best the 3-4 times a day dosing rather than more.  Each time another amount of T3 is created or added to, patients are looking for either a good reaction (continued good heartrate, blood pressure and temperature), or a bad one–hyper-like symptoms such as high heartrate, BP or temp, which would send the message that one may need to go back down to the previous dose for the time being. Paul Robinson’s book is a good resource.

Generally and after raising a little at a time over several weeks or a few months, patients on T3-only eventually have their highest amount of T3 first thing in the morning, such as 20 or 25 mcg, then subsequent lower doses. (You may not be able to go that high at first.)  You’ll see optimal total doses of T3 ranging from approx. 45 mcg or higher. Some do go higher due to digestive issues. It’s very individual and based on the removal of symptoms, pulse, BP and temperatures. Some dose more T3 in the winter than in the summer.

If I’m lowering my RT3, how long does it take? It generally takes 8-12 weeks for the RT3 to fall, and at those benchmark weeks, you may suddenly feel a little hyper as the T3 comes up and is better able to reach good cellular levels.

At any time, the above dosing could change depending on if you may need to go longer before the next dose, or shorter–all depending on symptoms. Dosing of T3 should never be about rigid times. 

***All the above may take a few months, depending on discovering and correctly other issues, but you eventually find a good dose of T3 that removes symptoms of hypothyroid. 

Why a bedtime dose?  Patients first heard about this with the late Dr. John C. Lowe. Turns out that your body can have its greatest need for T3 during the time you are asleep! But not everyone can tolerate T3 at bedtime, so you’ll have to experiment.

What about cutting up tablets? You’ll need a quality pill cutter.

How can I expect to feel on T3-only? Great, say many patients who finally resolve their low iron and adrenal issues.  Many end up going back on natural desiccated thyroid if they don’t have a cellular issue with T4, since it gives back what your own thyroid would be giving: t4, T3, T2, T1 and calcitonin.  In the meantime, T3-only can help a lot!

Will I always dose 3-4 times a day? Not necessarily. When some have been on T3 long enough, they might even be able to dose twice a day, but three times is common and you might feel a LOT better dosing three times rather than more once you’ve been on T3 long enough.

**Need to talk to other patients about the use of T3-only? Join the STTM Facebook T3-only page from here.  You’ll also be able to talk to the man who discovered the T3 Circadian Method for better adrenal function. 

***Take the revised STTM book with you to your doctors appointment.