T3 and tension

I started taking T3 4 weeks ago together with T4 - I have been taking T4 for last 5 years. Prior to starting T3 I was on 150mcg T4.

As my endo recomended, first week I was dosing 125mcg T4 and 6.25 T3. From the second week untill now I am taking 100mcg T4 and 12.6 T3.

Apart from feeling tired, I became nervous and tense. Everything irritates me and my tolerance to others suddenly has shrunk. I also got my period a week too early just few days after starting T3.

I will be checking my hormons in couple of weeks but in a meantime wanted to ask if anybody experienced anything similar after starting T3?


Featured Content

Join our community

The community helps everyone affected by thyroid conditions by providing support, information and guidance.


Featured by HealthUnlocked

20 Replies

  • Well tbh irritability can be a low or high symptom, but as you've just raised your t3 I would guess that you've raised it a bit too quickly, before the levo has been allowed to fall. You might want to give it a week or so after you reduce levo, let your levels fall a wee bit, then add in the higher dose of t3, see if it makes a difference.

    What are your pulse, temp and gut like? Fast or slow? That might give you a clue.

    Was your t3 quite low on your last bloods?

    One way to know where you are is to go back to your 6.25 t3 dose and see if you feel better by the end of the day. If you're feeling really overstimulated (fast pulse etc) you can skip a t3 dose entirely, see what that feels like.

    Alternatively if you don't feel better after a reduced/skipped dose, it may the effects of reducing your levo. I have had anxiety through the roof when reducing levo, it might be the falling t4 (just my own guess). I think some people are sensitive to this.

    It is not unusual to have a few teething problems when you first start a new thyroid medicine, it can feel different to levo alone.

    I'm not a doctor, I take levo/t3 and have tweaked it left right and centre so I'm only speaking from my own experience. :-)

    Re blood tests, you may want to wait the full 6-8wks on a steady dose before your bloods, to give the levo a chance to stabilise.

  • Thanks puncturedbicycle for all the advice. My free T3 prior to taking T3 tablets was 4.3 (2.6-5.7) 54.8%, free T4 17 (9-19) 80%, TSH 0.12 (0.35-5).

    I was on 150mcg levo and was feeling unwell, tired, sleepy, had terrible headaches for days, hair loss and very dry skin.

    I actually feel sort of better physically now but nervy, no headache for over 4 weeks that is very unusual for me - just tired and sleepy all the time.

    As I'm almost 5 weeks now on this dose, it makes a sense to continue couple weeks more and then check T3 and T4.

    Will be back when I have new results.

  • Perfect, that sounds like a plan. Then when you know where you are you can adjust your meds, see how you feel for another six weeks, then test and repeat.

    I look forward to hearing what your results tell you.

  • Hi Grace. Yes, I definitely feel more nervy on T3. I have been off it and reintroduced it recently so notice the difference.

  • Have you optimal levels of B12 - Ferritin - Folate and Vit D ?

  • Before starting T3 I supplemented all these to be sure my symptoms are not due to deficiencies.

    25OH Vit D3 146.6nmol/L

    serum B12 1794ng/L (177-883)

    serum folate 14.4ug/L (3.1-20.5)

    Ferritin wasn't done but month ago I finished course of ferrous fumerate. Will check it in few weeks time.

  • Hello Grace, I can't help I'm afraid with the T3 as I'm only on T4, but I'm curious as to how you're going to get your hormones checked? Do you meant your thyroid levels, or are you able to get other hormones checked somehow as I've been told by the doctors that it's impossible to do so? Would love to know your opinion as its something I'd be very interested in doing myself. Thank you :)

  • Snowflake, we have to be able to know our hormonal status. It's very important in balancing our body. Below are a couple of great articles to help you understand why we need to check our sex hormones and how we can get it done:


    and why we need it:



  • Great I'll check it out thank you :) apologies for jumping in thread but looked like an answer maybe here!

  • Hi Snowflake,

    Yes I meant my TSH, free T3 and free T4. My endo have already given me the referral for blood test.

    Which other hormones you wanted to check?

    I'm lucky to finally have resonable endo. Before putting me on T3 he cheked my adrenal glands and couple of different things.

  • That sounds great and I'm so pleased your getting answers and help! I'm would just be looking into estrogen, progesterone and testosterone I guess as a start. Looking at the links kindly supplied and just through general knowledge really I think a saliva test would be a good way to go but I'm looking into it. Not something I've ventured into before as I've been always told that it's not possible as they fluctuate so much during the day. Thought you may have some more knowledge in it after reading your post, but thank you for replying :) good luck on your journey!

  • I personally believe the changes your Endo recommended to your meds are too quick, you should be on a dose for more than a week before changing. Also levo stays in the blood for a good week, when you lower a week later and raise the T3 you are still basically on your old dose of T4 but now with more T3! I'm not surprised you feel the way you do!

    I think you'll know the question coming up :) ....

    Do you have recent blood tests to show? The addition of T3 and the way it's done is quite dependant on current tests and what the end goal is.

    I did experience something similar when I started T3, but I actually raised my levo along with T3 at the same time (as T3 lowers FT4). I split my doses to make it easier. I started with 5mcg T3 and 75mcg levo. Then upped it to 10/100 a few weeks later. Each increase gave me a bit of extra "boost" heart rate was a bit high, and yes I did become a little snappy with my family. But it rolled off after my body adjusted (it takes a good 2 weeks to adjust to a dose of T3, which is why I think you're adjusting too quickly, also consider it takes 6 weeks to adjust to a dose of levo).

  • Thanks dang for your reply. It makes a lot of sense what you are saying. My endo wanted me to start straight away with 12.5 T3 decreasing the T4 at the same time but I was scared as previously every increase of T4 was making me so sick so I asked whether I could do it slower. He said to try 6.25 T3 for a week and if I'm ok then can double T3. The reason he wanted me to decrease T4 was that my TSH was very low 0.12 (0.35-5). I tried to explain that in this situation TSH it's irrelevant because it's suppressed by T4 I'm taking. Anyway, I think the decrease of T4 was too fast and too much that's why I'm so tired and slipy all the time. I will be checking T3 and T4 in couple of weeks. This will give me an idea what to do next. Thanks and good luck to you.

  • You're welcome :) Yes that makes sense that it might have been a bit fast. It's not always easy adjusting doses but it's good that you have a test coming up with both T3 and T4 should really help get you to the right place!

    All the best!

  • Well you are now taking less than the equivalent of 150 T4, so if you felt undermedicated on that, you could be worse off now, you might actually need T3 on top of your T4, not instead of. I stayed on the same dose of T3 for a couple of months before raising it.

  • Thanks Angel_of_the_North. It's probably the case that I'm now undermedicated. However will continue week or two and check my T3 and T4 and will have clearer picture what to do next.

  • It's hard to be certain without test results but those do sounds like symptoms of too much Thyroid hormone. I think I would be inclined to revert back to your previous dosage of T3, with the lower dose of T4 and see how you feel. Then if you start to feel hypo symptoms increase the T3 slowly.

    The body is much more sensitive to T3, so 25mcg of T3 has a lot more effect than 25mcg of T4. As others have said it is also wise to increase T3 slowly to give your body chance to become accustomed to the higher demands it makes. Also T4 does not leave your systerm the day you stop taking it, it can hang around quite a while.

    You can get anxiety with both high and low Thyroid. With high thyroid it's likely to be more hyper and may be accompanied biy a fast pulse or raisied blood pressure. You are are also likely to sweat more and be hotter with overdose, in contrast to rather cold when hypo.

  • Yes, too much T3 can make one feel irritable and "nervy". This has happened to me. The T3 "power factor" is 3-4 (your endo should know this!), so reducing T4 by 25mcg and then quickly going to 12mcg T3 sounds like you went to too much T3, too fast. Remember, when you reduce T4 you don't reach a new stable state until 5-6 weeks (5-6 half-lives) have passed. If I were in your shoes, I would drop T3 back to 6mcg now. (And if you want to, go off T3 for 1-2 days before resuming, I have done this on several occasions.) I would not suggest lab testing unless you have money to burn; the bottom line is, when you are close to the right dose, the best way to get there is by how you feel. I have found that I can have TSH/FT3/FT4 labs that are well within range, yet still feel like I am on the edge of hyper. I am also one of those people (my doc has several) that do best when their FT4 is low in range.

  • Hi, just bear in mind it takes about 6 weeks to stabilise on a new dose,regardless if it's T3 or T4. I have recently gone back on T3 after a few months trialling T4 alone (which didn't work very well for me).To start with the T3 didn't seem to work at all,I was really tired,even though I had been taking it for 15 years with no problems. Now it's coming up to 6 weeks on it again and I am starting to feel better.

  • Your instincts are good!

    Yes, you've taken too much T3 for you at this time. T3 is gradually increased and as the body gets used to it, you may find you eventually will need more. But it has to be done in as gradual a fashion as your body requires. You will know because (for you) you'll once again find the symptom of nervousness, tension, and irritation.

    I also feel it is very wise of you to have your sex hormones checked. When there is an imbalance there, it affects how we handle thyroid hormone.


You may also like...