Thyroid UK
82,662 members97,701 posts

T3 only query

Hi all!

I've been feeling good on T3 only. Had my first test result on Tuesday (GP called, concerned about results but when I informed him I am doing well and to refer to endo's instructions he didn't push to reduce. I told him I am doing T3 only but didn't ask dose etc).

I'm taking:

AM: 50mcg

Afternoon: 20mcg

Bedtime: 10mcg


TSH: 0.27 (range 0.5-4.5)

T3: 7.1 (range 3.8-6.9)

T4: 4 (range 9-23)

My question is regarding the T4. Is it ok it is this low? Or does it not matter now that I'm T3 only.

About to post another question about disability....


7 Replies

I would include 50 mcg levothyroxine. It probably won't make a difference but I think some tissues would benefit. A gut feeling rather than science.

I have found the night time liothyronine to be more important than day time. Too much and I can't get to sleep, too little and my sleep is shallow and unrestorative. I'd take equal amounts during the day. If you find you can't get to sleep then you are taking too much.


Pennyrose, T4 is a storage hormone for conversion to T3 and it is usually low when patients take T3 only. FT3 is mildly over range. 5mcg dose reduction would bring it into range.

1 like

Thanks so much clutter, I could look to reduce my morning dose. I'm about to start at the gym though (one onsite at my new job) so should I wait and see or just do it and then adjust accordingly? Sorry for picking your brain but you know sooooo much! You should charge 😀 X


Pennyrose, the over range is so mild I shouldn't worry about it and working out will use T3 anyway.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


How long did you leave between your last dose of t3 and your blood test? It should be around 24 hours. If not then that would put your t3 slightly over, but if you feel good then it really shouldn't matter. On t3 only, my t4 is only 3.7 last time it was checked. That is all my thyroid is making.

Jo xx


Hey lovey, I took all my doses on the Wednesday including before bed, then didn't take my Thursday morning dose. The blood test was at 1140 which is a bit later than I normally have it done (usually before 930).

Feel good :) x

1 like

I wouldn't add in t4 unless you know u aren't creating reverse t3. The problem is with taking t4 on a large dose of t3 is that ur body is likely to just turn most of it into rt3 as u have enough t3 in your blood. I take t3 only now having been on t4 t3 combo for thirteen years because I started to make rt3 in too bigger proportion and I feel as good as I can on t3 only having tried NDT too.


You may also like...