Levo Increase, Heartrate

Hi all. I'm still working with my endo to raise both my FT3 and FT4 levels and feel better. I was on 75 mcg of Levo for 30 years, but did not feel well starting about a year ago. I started on Cytomel 5 mcg about 6 months ago, and have been slowly increasing the Levo. My latest increase is to 100 mcg of Levo along with the 5 mcg Cytomel. My latest labs did show a slight increase in both levels when I was on 88 mcg Levo and 5 mcg Cytomel:

FT3 - 3.0 (2.3 - 4.2)

FT4 - 1.1 (0.8 - 1.8)

TSH 0.02 (0.40 - 4.50)

After those labs, my endo increased the Levo to 100 mcg and kept the Cytomel at 5 mcg. I know I need this increase to get my levels up over the halfway mark, but twice I have attempted to increase to the 100mcg and my heart pounds at night, causing insomnia. I've checked the rate, and it's really not that much faster, it's just pounding. My usual resting rate is 68, and now it's 80 BPM even at rest.

I noticed this increase in heartrate immediately the first day I began taking the Levo. I didn't think this wasn't possible with Levo because it takes a few days to start working, unlike T3. So, do you think it's really the increase in the Levo, or am I just stressing out?

The last time I tried to increase the Levo to 100 mcg was a month ago, and I went back to my 88 mcg dose after 3 days because of the pounding heart. It's not palpitations, just beating faster and harder. I really was having a lot of stress and anxiety at that time that could have caused the increased Heartrate and insomnia. (I have chronic insomnia, but it had been under control lately until I increased the Levo.)

So now a month later, I am again trying to take the 100 mcg of Levo along with 5 mcg of Cytomel. Of course I had insomnia and pounding heart last night after the first dose that morning. I still took that dose again today. Should I just keep on with that increased dose? Will my heart eventually slow down if it's the Levo that is causing it?

22 Replies

  • Do you know how well you convert? If you don't convert well, there's no point in trying to raise the FT4, you risk it converting to rT3. Besides, the body will just hang on to what it wants, no matter how much you raise it, because you're taking T3.

    Seems to me it's the T3 you should be raising. 5 mcg is only a tiny dose, and your FT3 is not even mid-range. :)

  • My FT3 did come up some with these last labs, and I was on the same dose of Cytomel. I was happy about that because it did show I was converting. I've improved my diet and supplements which may be the reason. I know the FT3 level needs to come up more, but so does the FT4. That was the endo's rationale for increasing the Levo. When that comes up to over the middle of the norm range, maybe she'll increase the Cytomel. I know she's already freaking out about the low TSH.

  • But what if it doesn't come up over mid-range? It might not, you know. As I said, the body only hangs on to what it wants. And if you're taking any T3, it doesn't want as much. Saying that the FT4 should be in such-and-such a place and the FT3 in such-and-such, is for people on T4 only. When you add in T3, it changes the rules.

    You cannot tell how well you are converting when you're taking T3, even if it's only a little bit. To know if you are converting well, you need to be on T4 only. So, do you have any labs from before you added in the T3?

  • Thanks for your input Greygoose. I was indeed NOT converting back in the days when I did not take the Cytomel. My FT3 was tested from 2012 on, and it was always on the bottom of the normal range.

    I did not realize that my FT4 might not come up because I'm on T3! And it looks like the endo doesn't know that either. No surprise there. That is discouraging because she has been very reluctant to give me more than my token 5 mcg of Cytomel.

    So, now I guess I'm confused as to what amount of each one I should be taking, and what labs I should be monitoring. Should I have stayed on the 88 mcg of Levo and increased the Cytomel to 10 mcg as a start?

  • If you felt good on 88 mcg of levo, yes. And, 10 mcg Cytomel would be better than 5. But, maybe go up more slowly than that? 7.5 mcg, then 10?

  • Thanks Greygoose. I was feeling ok on the 88 mcg of Levo. I don't know if I'll be able to convince the Endo to increase the T3. It's so easy to get and inexpensive when it's ordered by the doc here in the U.S. Wish me luck!

  • I'll keep my fingers crossed for you! :)

  • Thank you! 😊

  • Frightening that the endo doesn't realised the only valid reading is your FT3 once taking it in any amount. My endo was on holiday atvmy last appointment but I saw a very nice chap who was horrified my TSH was on the floor and said we have to raise it etc etc so I said what his 'boss' had said but he still wanted to read the riot act about the harm I was doing to my body. Quite calmlybi asked was he sure my pituitary was working well and then had to explain why I'd said that! Still shouldn't shake him off it so sat and listened to him trying to frighten me and I said I'm carrying on as before! It worries me that so many don't know this and yet to me it is so logical. The only active bit is the T3 so when your body senses you are getting it from elsewhere then it realised it doesn't have to do the conversation to T3 so thstcreading is much lower and the pituitary realised your FT3 level is fine so doesn't have to tell your thyroid to produce more! Simple!!

  • So true silverfox7! I wish I could find a doctor who was knowledgeable and didn't have an attitude when you talk to them. My endo sometimes calms down when I remind her that the low TSH is not going to cause bone loss, heart problems, etc. when my FT3 is near the bottom. Other times she gets an attitude. ARGH!

  • Hello; I don't know what your situation is and would be sure to test or consult a doc before doing anything, but all I can tell you is once, when first starting T3 (with levo 100mcg, T3 at 20mcg, then) I had heart rate increase, which did not stop when we reduced the T3; went to cardiologist who found nothing wrong but who suggested I try 400mg Magnesium citrate (not oxide), once per day in the middle of the day when I take all the other vitamins, my heart settled right out, really quite fast, only a few days later, maybe 3-4 days later. We re-elevated the T3, and all was still well. Of course everyone is different and that's just my experience, but a little magnesium citrate can't hurt? Best wishes!

  • Thanks for that input Acoldiron! Very interesting that magnesium citrate took care of the fast heart rate. I currently take a chelated Magnesium glycinate 200mg at lunch and dinner. It is supposed to be absorbed better than the citrate. I'm glad your problem was resolved!

  • How's your blood pressure? If it's up, too, might be too much thyroid.

    Perhaps your adrenals are a factor? Have you had a 24 hr saliva cortisol test?

    I had similar heart pounding and high pulse and we had to halve the thyroid and ratchet up the hydrocortisone due to adrenal dysfunction...

    Not sure what's going on, just suspect there may be more variables.

    Magnesium glycinate is a good idea, too. And how are your selenium, iodine, dopamine, norepinephrine and epinephrine levels?

  • Hi Learner1. My BP is normal low. I did the 24 hour cortisol saliva test this past year and it was ok, but that is just my interpretation. All the levels were well within the range except one that slightly below. I've never tested selenium, iodine, dopamine, norepinephrine or epinephrine.

    I think you're right about there being some other variables. One might be anxiety. My heart seems to be calmed down a bit today. I'm on the third day of the increased Levo dose. Still trying to figure this all out!

    Thanks for your input!

  • Hmm... how's your gut health? 90% of serotonin is made in your gut...

    Gluten free diet? Food allergies? Imbalance in your microbiome? Nutrient deficiencies?

    You might do a Genova Diagnostics NutrEval FMV with Amino Acids. It would test B vitamin status beyond folate/B12, GABA, glutamine. taurine, and other aminos, neurotransmitter metabolites, some heavy metal toxicity, and high level gut health. Their website has s sample test...

    And if one number was low on the adrenal test previously, might be worth further attention.

    Keep at it, though... something is going on. You'll find it!

  • Thank you Learner1! I'll check out that lab website. I appreciate your encouragement!

  • I've read a bit about low iron and dose increases causing Palps . I've had the same as you mention but for me it was because I'd gone hyper t4 over 24. and also as I have cardiac stuff going on anyway , I have to increase slowly .

    So...How's your iron ?

  • Hi 108Optimist. My Iron is ok, and ferritin 59 (13 - 300) earlier this year. I had mixed reviews about whether I should supplement with iron. Most said no, including some from this group. Because of it's possible toxicity, I don't take iron. I have since improved by diet with more meat and iron rich foods. I used to eat mostly vegetarian.

    Perhaps I have increased too quickly from 88 mcg to 100 mcg of Levo, although in the past, I've handled the increase from 75 to 88 well. Maybe I've gone over my required need, but my labs were below the halfway point on both FT3 and FT4. Labs due to be drawn in 5 weeks. I don't have any other symptoms of hyper other than faster heartrate and insomnia, and the latter is an ongoing problem.

    It's all pretty complicated, isn't it? Yikes! trying to learn and adjust accordingly! Thanks for your comments!

  • Thyroid so complex ! I aim for 70 for ferretin but cannot get over 40 no matter what I do !

    I hope you find your answer soon. good luck x

  • 108Optimist I'm hoping my ferritin is higher next time I check it. The good news is that my heart has calmed down and I'm sleeping on the higher dose of Levo. I'm going to keep on this regimen for 5 more weeks, and will be hopeful that I continue to feel good, and my levels of FT3 and FT4 rise. If not, well, more tweaking and sleuthing for problems! Thanks again.

  • I've just increased my meds tpo. last time I upped I got the Palps etc but not this time ☺

  • 108Optimist that's good news! My heart has settled down for the most part here on week two of the increased dose. And I'm sleeping fairly well. Yay for both of us!

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