Help me understand

[lauramay36]

Hello i was wondering if someone can explain to me the difference with T3 and levo please XX

[puncturedbicycle]

Levo (t4) is a storage hormone and has to be converted to t3 in your body. Hope that helps.

[Learner1 in reply to puncturedbicycle]

Agreed. In a healthy person, T4 converts to T3. But, it doesn't always.

With a lot of stress, it can convert to reverse T3 instead, which has no real function. So TSH can look perfectly normal, free T4 can look normal, but free T3 may be low while rT3 is high.

There are many health conditions that can affect proper thyroid function, you need adequate nutrients like selenium and iodine, and genetic factors may have an impact, so its highly individual.

A good doctor will test all of the above, along with thrlyroid antibodies, and then, most importantly, ask you how you feel to come up with a treatment plan that may include T4, T3, NDT, and/or nutrients.

[shaws Administrator in reply to Learner1]

This is an excerpt from a Scientist/researcher/doctor re RT3:-

If you go to date March 24, 1999 to read the answer:

Another enzyme called 5-deiodinase continually converts some T4 to reverse-T3. Reverse-T3 does not stimulate metabolism. It is produced as a way to help clear some T4 from the body.

Under normal conditions, cells continually convert about 40% of T4 to T3. They convert about 60% of T4 to reverse-T3. Hour-by-hour, conversion of T4 continues with slight shifts in the percentage of T4 converted to T3 and reverse-T3. Under normal conditions, the body eliminates reverse-T3 rapidly. Other enzymes quickly convert reverse-T3 to T2 and T2 to T1, and the body eliminates these molecules within roughly 24-hours. (The process of deiodination in the body is a bit more complicated than I can explain in this short summary.) The point is that the process of deiodination is dynamic and constantly changing, depending on the body's needs.

web.archive.org/web/2010103...

[hachiko in reply to Learner1]

-- if patient has begun Levothyroxine and in the following lab test the figures for the T3 has come up, is it an indicator that the body is converting T4-->T3?

[Learner1 in reply to hachiko]

I don't see your labs, but if your free T3 is low, that would be a good clue it's not converting, especially if free T4 and/or reverse T3 are high. The best clue is your symptoms - do you FEEL hypothyroid? If so, be persistent to find the answers. There are other reasons you could feel hypothyroid, too.

Good luck!

[Sylvrfox]

Levothyroxine medication only contains T4. It is a storage hormone that our body is supposed to convert into T3, T2, calcitonin etc. some people have trouble converting it into T3, etc., whether it's T4 from medication or the T4 our body makes, so supplementing with T3 may be necessary to feel well. If your doctor tests only T4 or TSH and not T3, and RT3 you won't know if your body is converting it (T4) to the usable form T3. If you have too much T4 the body will start converting it to RT3, reverse T3 that will bind to the sites on your cells where T3 is supposed to bind and you will still feel hypo. TSH is just a pituitary hormone produced to tell your thyroid gland to produce T4. TSH on it's own is kind of useless. If RT3 is too high you can bring it down by taking more T3 and reducing Levo doses. Does that help? Most doctors are brainwashed by big Pharma drug reps to only prescribe Levo or Synthroid and they won't test for T3, RT3 but insist on it! If they won't find a functional medicine doc or a naturopath. There are several good books; STTM - stop the thyroid Maddness, and The Root Cause. There is also a Facebook group called FTPO-thyroid topics that are great sources of info! I learned all the above and more after joining. You have to request to join and once they see you are a real person the will accept your requests. Good luck!

[Clutter]

Lauramay36,

Levothyroxine (T4) is a storage hormone which converts to the active T3 over a few days. Liothyronine (T3) is the active hormone which doesn't require conversion. T3 is 3 x stronger than T4 and has a much shorter half life so is out of the system 3 to 3.5 days after last dose.

[sulamaye]

Levo has 4 iodine molecules one of which needs to be knocked off by the body in order to fit into the cell receptor, in effect creating t3. T3 is the synthetic form of this and already has only 3 iodine molecules so does jot need to be altered by the body in order to fit into the cell receptor and work.

[lauramay36]

Im sorry im ment to ask if the T3 tablets are the same as Levothyroxine as im finding it hard to Get the T3. To be honest i had been taking T3 to help with weight loss and to bost my Energy as i was always feeling low and tired i started usunę T3 as my doctor wouldnt test my thyroid . I started using T3 for a while and stopped but my mood is back to being low so i was wondering if T3 is the same as Levothyroxine as im finding it hard to Get T3 x

[Clutter in reply to lauramay36]

Lauramay36,

No, they are different. T3 is Liothyronine and T4 is Levothyroxine. Both are prescription only in the UK.

[Eddie83]

T4 (levothyroxine) is the thyroid storage hormone, which contains 4 atoms of iodine. T3 (liothyronine) is the thyroid active hormone, which contains 3 atoms of iodine. rT3 (reverse T3) is the undesirable form of T3, which is a right-hand isomer of the T3 molecule, and prevents the positive effects of T3 on your metabolism. The FT3 (free T3) test is critical because it tells you how much T3 is free and available to act on your metabolism. The ratio of rT3 to FT3, or rT3 to TT3 (total T3), is used to decide if your body is making too much rT3 to function well.