General question about levo/synthro dose, over medication and testing hormone levels. I switched from levo to synthroid, and felt hyper with the same dose (37.5 for 5 days and 25 for 2 days). I had palpitations, insomnia, nightmares. Decreased the dose after a week myself, felt better, then slightly hyper again. After 2 weeks of suffering started taking 25 daily, and after 2 weeks heart racing is back. Endo doesn't want to change the dose but I can't live like this. My previous endo would correct the dose after 7 days if I felt bad , but new endo wants to wait 4-6 weeks. I have residual tissue after thyroid surgery and it is active, that's why I don't need much hormone. My T3 is 3.80, top of the range, TSH 0.54 and T4 0.74. What others in this group would do if they have heart palpitations several days after starting a new dose or new levo brand? Wait 4 weeks? Or fight with endo about the dose? Or cut the dose until feel better?
Synthroid and heart palpitations/racing - Thyroid UK
Synthroid and heart palpitations/racing
I switched from levo to synthroid, and felt hyper with the same dose (37.5 for 5 days and 25 for 2 days)
We really need the reference ranges to go with your results, because reference ranges vary from lab to lab. And are your T4 and T3 results from Total T3 and Total T4 tests or from Free T4 and Free T3 tests? The Total tests are not helpful, just the Free ones are.
Your dose of Levo (please be aware that synthroid is levothyroxine) is absolutely tiny. And I just read a previous post of yours and have discovered you've had a thyroidectomy and only have a tiny remnant left. I'm not surprised you feel awful. I'm just surprised you are still alive.
Have you ever had your nutrient levels measured? If yes, do you have a copy of the results, and could you copy them (with reference ranges) into a reply.
If you haven't had any nutrient levels checked - specifically, iron, ferritin, Vitamin B12, Vitamin D, folate - you really need to get them tested and then optimised. Don't just rely on a doctor because they usually think that any result in range is absolutely fine. And also, don't assume that any supplements are in the right form for you. There are four kinds of vitamin B12 available. Some are better than others. There are also multiple kinds of folate available for supplementing. Folic acid is the worst one but it is the one that doctors always prescribe if levels are low. There are many different kinds of iron supplement available, some more easily tolerated than others.
The reason that I mention nutrients is that many people have discovered that their intolerance problems with thyroid hormones in any make go away when they start improving their nutrient levels. I wasn't able to tolerate thyroid hormones until I started working on raising my iron and ferritin.
I absolutely 100% would not lower my dose in your circumstances. I would get nutrients tested and start doing what I could to optimise them. Then you might find you can tolerate hormones better and eventually will probably need to raise them substantially. But it is impossible to say without results AND reference ranges.
Thank you, Humanbean! My vit D is pretty low. I'll make a table of all my labs to see the whole picture. I get each test result separately and can't share them like a single screenshot, have to open each file for each test. I never gave a thought to possible connection of not tolerating levo and nutrition staff. My PTH is very low after the surgery and I'm taking 2000 g vit D, calcittiol and 2000 mg tums as Ca supplement daily.
Human bean, thank you, nutrient deficiencies could explain my same symptoms on low dose of levothyroxine. Do you have a reference for testing iron, ferritin, B12, folate with hypothyroidism? I’d like to present this info to my doc. I checked but didn’t see this in the NICE report that was referenced in this blog. TIA
This is a really good article that might be helpful.
Humanbean and others, thank you for your kindness. I put together my case history and recent test results, and would like your opinion: do I need to reduce synthro dose further? Am I hyper? Here is my history: benign multinodule goiter since 2003, thyroectomy in 2017 due to nodule growths and history of radiation exposure (full thyroid removal). Complication: one parathyroid gland damaged, low PTH after surgery, take Vid D 2000 mg and Calcitriol daily. Often have pins and needles. Hormone replacement: started levo 125, intolerance, year after surgery nuclear test revealed remaining tissue 2x4 cm, since then the doze was reduced gradually to 37.5 levo daily. In Dec 2021 switched to synthro, same dose, palpitations, need dose adjustment and find out what's going with residual tissue since it seems so active. Test results are below. I also don't mind to share my experience with others, maybe there are some people with similar history and complications. I replied here to Humanbean but admins may post this message for others. I haven't yet met anyone who have active residual tissues after the surgery and would welcome any advice and experience!
Palpitations, heart racing, heavy chest
why does t3 decrease t4 levels and can this effect symptoms. 
Racing heart rate - RHR 90+ hypothyroid 
New found hyperthyroid symptoms - a little too hyper
