Thyroid UK
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Low BPM and Body Temperature.. with Cytomel?

So my TSH was 5.8 (range 0.4-4.5 uIu/mL)

Free T4. was 1.25 (range 0.82 - 1.77 ng/dL)

Free T3 was 1.5 (range 2.0-4.4 pg/mL)

Reverse T3 was 20.2 (range 9.2 -24.1 ng/dL)

My LDL and total cholesterol was very high and my free testosterone very low.

So after looking going to many doctors.. one finally said.. this is all related to my low T3.

He said my ratio from Free T3 to Reverse T3. was 7% and it should be higher than 20%.

He gave me 25mcg daily for a week of CYTOMEL. and asked me to take Temp in the morning.. and check my heart rate.

Second week I'm on 50mcg.. and today I check my temp in the morning and was 95.6 (which is low I believe.. ) I than took my 50mcg.. and an hour later it was 97.6.. still not in 80s.)

My resting heart rate.. is 60-64 bpm. not high like people report on T3.

Is it that my metabolism was on the bottom end and it still adjusting.. or will my doctor increase it to 75mcg.? I'm just concerned that I lose muscle since T3 is catabolic. Thanks

6 Replies


It will take a lot longer than a week for temperature and bpm to improve after you start taking Cytomel. Temperature isn't a particularly good indicator of thyroid status as it is usually lower in women than in men and may remain low even when optimally medicated.

Your GP should retest your TSH and FT3 six to eight weeks after you started 25mcg Cytomel. Blood tests are the best way to determine whether T3 dose is sufficient. As you are taking T3 only your FT4 will drop below range. You should be looking for TSH 1.0 or lower with FT3 3.54-4.4.


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

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Thank you very much. I actually have more time. it was 2 weeks with 12.5mcg.. and 1 week with 25mcg.. this week has been 50mcg.

I asked because I saw people posting that there body temperature increased and bpm increases almost right away.when you take cytomel.



Some people claim instant improvement after a day. It can take a lot longer for most people.

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I agree with the posts above and would just like to add that I think you have hit on a good doctor and advise you to hang on to him. Most docs do not even know the difference between Total Ts and Free Ts and go to a blank stare if you mention reverse T3. I would do exactly what he is recommending because at least he has read and remembered the right books and research papers. Yep, I think you have found a winner.

Wish I knew more about T3 vs muscle loss, I will research it because my first hypo symptom is terrible thigh muscle pain. Thanks for mentioning that.

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I experienced muscle loss on Levothyroxine. Thigh muscles were so weak and sore I had to haul myself up by my arms when I squatted to look at bottom shelf items in shops. I'm fine now I'm taking T4+T3.


Oh yes, I remember my hypo shopping trips. My thighs hurt so much that I had to park near the cart rack so that I only had to walk a few yards before I could grab onto one and amble round the supermarket leaning over it. Now I ride my bike and dig my garden 'til the sun goes down. Yeah for T3.


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