Thyroid UK
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Is it always necessary to reduce levothyroxine dose when adding T3?

I would be very grateful for any feedback. If TSH & Free T4 levels are optimal but Free T3 is low, is it still necessary to reduce Levothyroxine? Wouldn't that alter TSH & Free T4 levels as well as the Free T3? Surely if TSH & Free T4 levels are optimal & you just want to increase Free T3 levels you would just add a small dose of T3 without altering the Levothyroxine dose? Any advice would be much appreciated : )

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Adding t3 will alter (lower) your t4 and tsh, not just raise your t3, so in adding t3 without reducing t4 you run the risk of being overcorrected. Having said that, my unorthodox doc added 10mcg t3 to my optimum level of t4 and I felt great for six months. I did go a little hyper according to tests (and I had some minor hyper symptoms).


What are you taking? Have you posted your blood test results here?


Rebecks, T3 is 3 x stronger than T4 so if you are optimally medicated on T4 and add in some T3 you are likely to become overmedicated. T4 is usually reduced by 25mcg for each 10mcg T3 added in.


Hi Rebecks.....I was on 100 mcgs Levo before being prescribed 10mcgs T3 at which point my Endo lowered my Levo to 75mcgs.It would seem that the added T3 is roughly equal to the amount of T4 that has been taken away therefore keeping to the equivalent of the original 100 mcgs Levo or thereabouts.( slightly over if you multiply the 10mcgs X3 )

If you add the T3 to your original dose of Levo you'll be raising your overall level.

It is different for NDT though where the T3 content needs to be multiplied by 4 to get the equivalent T4 ( this confirmed on my Armour Thyroid Patient Leaflet) so worth bearing in mind if you ever use it.


Just for information. This is a link re T3 and there are other topics at the top of the page.


Thanks Shaws......have only just picked up your post after my lengthy post to Clutter.

I called up the link for T3 and can see it needs a lot of absorbing so will read that this supposed to be outside gardening......much to do in preparation for handy man coming on Tuesday to replace broken goes on !! x


Hi the T3 link with interest! It makes you wonder why our bodies make T4 in the first place doesn't it? I earlier stated that I felt my best on a combo of 1 grain Armour / 10mcgs T3 and then got scared ....probably because I was due to see my Endo and was experimenting and not on my prescribed meds.However,I think it's time I concentrated on listening to my body and how I feel.I think in the past so much has hung on blood test results that we are inclined to be obsessed about them.Quite honestly ,when I think about it my Endo doesn't refer to them much at all. He prescribed my T3 and is also happy to monitor me on Armour though can't prescribe it,so I really do have the power to sort myself out with more confidence.

Thanks as always for your input.

One little aside........I won't be able to look at a tin of baked beans in quite the same way now............opened or unopened !!!!!!!! X


Mother Nature must have a purpose when she provides a full range of thyroid hormones. The difference may be that both T3 and levo are synthetic but T3 is the Active which doesn't need to be converted.

You seem to have a good Endo. Have you passed his name onto if she didn't give you it in the first place.


Yes I think I am very fortunate and sent Louise details after first seeing him last November.Have since recommended him to other Essex members and actually met one of them in July as we were both at Endo's clinic on the same afternoon.

Hope you are well x


I know this is three years ago but how did u feel adding that extra t3


Hi bindy2, adding T3 was the best thing I ever did! I have been adjusting doses throughout the years & I'm currently on 50mcg T4 & 50mcg T3 (taken in 2 doses). I can't say I'm 100% but I have enough energy & feel good enough to be able to lead a normal life. Good luck with everything : )

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Thank you xx


Thank-you all so much for replying, it's all beginning to make sense now.

I'm 45 yrs old & have had hypothyroidism for 15 years. I have been feeling ill with all the classic hypothyroid symptoms for the last 5 years despite optimal levels of TSH & FREE T4. My main concerns are the severe fatigue & weak/aching muscles & joints. After many visits to Drs & getting nowhere I decided to do my own research. I discovered that for some hypothyroid patients, if FREE T3 levels aren't optimal (about 3.8) hypothyroid symptoms can occur. I managed to get hold of T3 tablets 25mcg which I cut into quarters (with great difficulty) & after much research decided to reduce my levothyroxine from 100mcg to 50mcg & have 2 x 6.25mcg of T3 (total of 12.5mcg) daily

So before adding T3 6 weeks ago my levels were as follows:

TSH - 1.11 (0.3 - 5.0)

FREE T3 - 2.2 (1.5 - 4.0)

FREE T4 - 1.27 (0.8 - 2.0)

After reducing the Levothyroxine from 100mcg to 50mcg & then adding 12.5mcg (6.25 x 2) daily I felt good for the first 2 weeks but then all the symptoms came back.

My levels after 6 weeks with the T4/T3 combo:

TSH - 1.5 (0.3 - 5.0)

FREE T3 - 3.0 (1.5 - 4.0)

FREE T4 -0.91 (0.8 - 2.0)

I'm assuming that the T3 is good for me as I felt so good the first 2 weeks. I'm also assuming that the symptoms returned due to a drop in FREE T4 & a rise in TSH (both of which were OPTIMAL before).

So what do I do to raise FREE T3 (to about 3.8), lower TSH (to about 1.1) & raise FREE T4 (to about 1.25)?

Should I increase Levothyroxine to 75mcg & take 2 x 6.25mcg (12.5mcg) daily OR Should I keep Levothyroxine at 50mcg & take 3 x 6.25mcg (18.75mcg) daily?

Any help is MUCH appreciated!! It's such a shame that there's something available for us to feel better & lead normal lives but Drs can't (or won't) help us & we have to rely on the internet & self medicate.


Hey! I know this is an older post and not sure if you'll see this (hoping you do), but my labs tend to run quite parallel to yours. Have you had any success and/or improvement/solution to this since you've posted? Would love your feedback!


Hi misscliocat, I've only just seen this!! I'm really sorry for the very late reply but I wasn't checking my emails as I wasn't active on here for quite some time. I too was looking for someone with similar history/lab tests. I know we're all different but it would have given me a guideline which would have helped a lot, so I'm sorry I didn't see this sooner. I was successful & improved a lot after months of perseverance until I found a dose that worked. I was doing very well for over a year on this dose but symptoms are beginning to return which means my dosage needs adjusting. This is why I returned to the forum (& saw your post!). How are things for you? I hope you found a dosage that works well : )


Rebecks, You reduced your T4 too much and are slightly undermedicated. T4 is reduced by 50mcg for each 20mcg T3 added. I would raise your T4 to 75mcg and if, after 3 weeks, your symptoms haven't improved add another 6.25mcg T3.

Taking oral T3 lowers TSH and FT4 so don't aim for the thyroid results you had on T4 only. Your FT3 has improved and will improve further and there's no reason why it shouldn't be 3.9 or 4.0 as anywhere in the top 75% of range is optimal.

Ask your GP to test ferritin, vitamin D, B12 and folate as hypothyroid patients are often deficient/low and these deficiencies can cause musculoskeletal pain, fatigue and low mood similar to hypothyroid symptoms. Post your results with the lab ref ranges (the figures in brackets after your results) in a new question and members will advise whether supplementation is required.

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Thanks from me too Clutter for the info you have given Rebecks on this never ending debate on T4/T3 combos and dosing.I'm absorbing it too.

I found that I was fine for a time with the added T3,but it never lasts.I tried 1 grain Armour/ 10mcgsT3 and felt amazing then after a while was worried that I was overdoing the T3 and might do damage long term as that combo meant I was taking more T3 than T4. and worrying I was out of balance.

I also think that I'm conscious of the fact that GPs now talk more about cost than they do about patient well being and only give a starter dose and that's it!!

What is becoming clearer is that the fact that maybe instead of still hovering over which route is best for me ....Armour....or T4/T3 combo I should concentrate more on raising my dose myself,but haven't had the confidence.

I know I won't get an increase of T3 from my GP so will probably need to source it myself.

I have a referral about my joint pain in my knee which probably needs some attention( loose body ......which brought a smile ) so something apart from a thyroid problem.Muscle and joint pain has constantly been one of my issues,always questioning the fillers.

Being under medicated for over a decade definitely didn't help.

However,time to concentrate on the " how I feel " and not worry so much about the logic and mathematics of everything.

Sometimes,with a GP who hasn't got any thyroid knowledge beyond a small amount of Levo and only seeing your Endo every 4- 6 mths you can feel like you're in the wilderness......thank goodness for TUK.x


Marfit, how one feels is always going to be a better guide than blood tests. Blood tests have their place because both under and overmedication can cause problems but as you know 'perfect bloods' don't guarantee one will feel well. Don't worry about the proportions of T4+T3 you are taking. The proportions of T4+T3 in NDT don't suit everyone and some find they need extra T4 while others need extra T3, so what is right for one doesn't suit another and you need to find what is right for you.

I hope your 'loose body' and knee is sorted out soon :)


Thanks Clutter I hear what you are saying and think I'm finally gaining the confidence to adjust my own meds as needed.

Thanks for your good wishes....May have to wait a couple of months for a hospital appointment for my knee.

I saw an interesting article by Arlene Phillips the dancer today saying that she was recommended rose-hip capsules for her joint pain and it has given her a new lease of life and is able to dance and run again.(recommended by an Osteopath and a Physio.).... worth a try.


Sounds interesting, Marfit. I think rose hip has a lot of vitC in it. Maybe worth a try. Make sure your vitD levels are high in range too.


Yes you are right.Many years ago when our sons were small we used to pick rose hips from the hedgerows and mince to make them rose hip jelly( arduous task with an old fashioned mincer) however,like jam there was quite a lot of sugar added.......think now it would be better to take a capsule.Arlene recommends GoPo Joint Health rose hip capsules,£17.99 for 120, from Boots and independent pharmacies...I will give them a go.

I do take vit D capsules so that is improving too.


Dear Clutter, thank you so much for the information....I will take your advice.

My vitamin D levels are low & so is my zinc & I have been supplementing these. My RBC's & platelets are low which indicates unexplained anemia (as my ferritin, folate, vit B12 & iron levels are all within range). I don't have the results available at the moment. As I understand these imbalances are caused by undertreated hypothyroidism & I'm hoping they will resolve once my thyroid meds are sorted : )


They may be in range - but are they towards the top of the range for optimal health ? Ferritin needs to be around 80.....


Hi Marz, my ferritin is at 76 (10 - 140) so I'm assuming it's ok : )


Rebecks, 70-90 is optimal for ferritin. Good ferritin doesn't rule out iron anaemia though. You need a full iron panel for that.

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