Thyroid UK
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New to Liothyronine Medication


I'm new to this! I have been having issues with feeling extremely tired and unmotivated and other problems for a while now and I recently had lab work done and my Dr has told me that my Triiodothyronine is low (3.2) while my TSH is at 1.080 and T4 is at 1.45.

She put me on liothyronine 25mcg ( half in the am and half in pm). I missed my first does and took half at 1 pm.

My question is when will it be ok to take my next dose and should I start feeling effects like energy boosts soon after my first dose?

8 Replies

I'm glad your GP has prescribed T3 for you. I am assuming you are taking no levothyroxine as usually a combination of T4/T3 is prescribed.

If you don't take levothyoxine at all I would take the 25mcg T3 when you get up with 1 full glass of water and wait an hour before eating.

I take 50mcg once daily and it makes for an easier life as we'd have to have an empty stomach for the second dose which might be inconvenient. It will take a number of days for you to feel an improvement and you might need an increase of T3 in six weeks if your symptoms haven't improved but I am glad your doctor has prescribed T3 for you as you don't convert levo into T3. That's good.

Levothyroxine has a long half life. Liothyronine is absorbed into our system in a few hours and it enters the T3 receptor cells. It's work then begins by sending out 'waves' for between one to three days.

I hope you feel an improvement soon.


Thank you for the advice!


Okay so I just got my follow up labs back and now my t3 is too high and my t4 is too low

What does this mean??


The blood tests they use are for the use of levothyroxine (T4) alone. Therefore if we add in liothyronine (T3) or take T3 alone the results cannot correlate. T4 converts to T3. Plus adding T3 the results will show a higher T3.

The following link is by a doctor who was also an Adviser to TUK. He only took a blood test for diagnosis and thereafter it was all about the relief of linical symptoms.

The main point of taking thyroid hormone replacements is to alleviate clinical symptoms, so dose is gradually increased to do so. If pulse or temp goes too high reduce to previous dose. The aim is for you to feel well with no symptoms.

The following have to be at an optimal level too:-

B12, Vit D, iron, ferritin and folate.


Hi Rprutch, 1pm sounds very late for a morning dose :) ideally it would be best to preserve the usual gap between doses, so if you usually take them at 8 and 12, on a day when you take it at 1, take other dose 4 hours later that would be 5. You just have to be careful that the 5pm dose doesn’t keep you awake into the early hours. But until you do it you won’t know. T3 sometimes makes me sleepy, but the morning dose never does.

You might feel an energy boost as you may be quite sensitive to it, having only just introduced it

Think with T3 it’s worth setting alarms on watches and phones to remind you as timing is more critical than with Levo, although my understanding is that you don’t need to take it away from food so much? (I wonder if shaws has a reference about this?)

I would never take my T3 as shaws does as it would cause me problems if I took such a large dose all in one go. The most I’ve taken is 20mcg, but we are all different.

1 like

Thank you!

Yes, I was told to take in the morning before breakfast and then before dinner but I didn’t end up getting my med until 1 so I took it then.

Thank you for the advice! I will take second dose at 5 and see how well I sleep tonight! Lol


I take one daily dose when I get up and feel well. This is advice from a Scientist who himself took 150mcg of T3 (in middle of night once a day). He and his thyroid hormone resistant patients take T3 but his other patients take NDT (natural dessicated thyroid horones). Dr Lowe was also an adviser to before his accidental death.


Or, I f it’s your first day, perhaps just take the lunchtime dose today, then tomorrow take at morning and lunch. That way you’ll get to see how you sleep having just taken one!


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