Can Levothyroxine cause Sweating and Hot Flashes?

I am going through optimization of my Free T3 and Free T4 as my TSH has been on the high side but my Free T3 and Free T4 were always low. The doctor explained this as the brain is sending loud messages (high TSH) to the Thyroid to kick out more T3 and T4 but the thyroid gland is not able to pump out more T3 and T4. I started on 50mcg Euthyrox Levothyroxine and 5mcg Liothyronine and this lowered my TSH and bumped up my Free T3 and Free T4 but my doctor wanted my T3 and T4 to be slightly higher. So then I started on 88mcg Levothyroxine and 10 mcg Liothyronine. This resulted in extreme irritation, sweating and raised my 7-day average blood glucose more than 10 points - unacceptable. So now I am on 75 mcg Euthryox Levothyroxine 5 mcg Liothyronine (doctor said she may raise this to 10 in the future). It has only been a few days but I am experiencing hot flashes so I am not sure if this might be too high for me - will see what it does to the glucose. So I learned that to really find out how your thyroid is doing you have to measure all three - TSH, Free T3 and Free T4 - and you can't assume that high TSH automatically translates to high T3 and T4.
Wishing good health to all!

Ugh, know all about brain zaps. I was put on Cymbalta. Took me 6 years from the time I started trying to get off (due to sever side effects) to finally off it. One of the side effects were brain zaps. I was on it about 10 years total. Never again will I get sucked into taking meds that are not life sustaining (like blood pressure meds, etc)

Couldn’t agree with you more! But when we are desperate and a doctor recommends something that will help, we tend to desire the quickest fix or at least I did. Hard lesson for me as I want to trust my doctors. Still with zaps upon awakening but I will persevere. This groups really helps! Thanks for responding.

Yes, we are monitoring all three with me as well. Levothyroxine Is very bad for side effects for me. I can tolerate up to 62.5 mcg with side effects that are just barely tolerated. When it’s bumped up to 75 mcg the side effects are intolerable. Unfortunately 62.5 is not enough to maintain necessary levels of t3. My gp won’t prescribe anything but Levothyroxine, so I am stuck on a waiting until I can see an endocrinologist. I’m hoping the specialist will just add some t3 medication and see how that goes. It’s been an issues for years, took til now to get my gp to understand how bad it is and I’ve been waiting months already for the specialist 😢

@catherinebird - it can definitely be a challenge to find a dose that works without unacceptable side effects. I also found the 75mcg Levothyroxine - 10mcg Liothyronine dose to result in unacceptable side effects. BTW my doctor (naturopath, not an endocrinologist) explained that levothyroxine affects the T4, not T3, and that liothyronine is used to raise the T3 so you may want your doctor to explain how the levothyroxine impacts the T3. There is another brand of levothyroxine called Euthyrox that is blister packaged and does not contain any dyes. Not all pharmacies carry it but some Walmarts do and for me it was the same price as Levothyroxine. The pharmacy technician told me that patients who use Euthyrox say that it works better for them and they would not want to change. The package insert states that available doses include : 25 mcg, 50 mcg, 75 mcg but not 62.5 mcg. If you read the reviews on drugs.com, Levothyroxine (5.1 out of 10 from a total of 859 ratings) rates higher than Euthyrox (1.6 out of 10 from a total of 164 reviews). The UK regulatory agency MHRA issued a drug safety update related to switching brands of levothyroxine in May of 2021. So this is something to consider. I am not a healthcare professional so am just sharing information as patient.
Have you tried 50mcg? What is your Free T4 when taking the 62.5mcg Levothyroxine?
Wishing you good health and that you find solutions in the near future.

Hi. Yes, I am well versed in understanding how t4 relates to t3. In my case the t4 levels are fine, but I am low in t3. My body does not seem to be doing well with converting t4 to t3. You have to have sufficient levels of the correct enzyme in your blood to do the conversion, which is one of the things an endocrinologist can investigate. 50 mcg of Levothyroxine is to low a dose for me, as even my t4 level crashes at that. At 62.5 mcg, my t4 levels are fine, but my t3 levels are not. At 75 mcg my t4 levels get too high and I get bad side effects, but my t3 levels are just barely reaching the minimum acceptable level.

I am in Canada and we do not have the same selection of thyroid medications that are available in the States or in England. There are only 3 available here, t4 replacement, t3 replacement and one natural sourced. Levothyroxine (t4 replacement) is the only thing gp’s will prescribe locally; therefore I have to wait to see an endocrinologist 😢
I’m hoping he investigates my enzyme levels and either prescribes an additional dose of t3 or switches me to trying the natural form.

see MD , not PA 🙂

I have minimal side effects with Synthroid. All general give me palpitations

After years of trying different thyroid meds my NMD put me on NP Thyroid. It's hard to get since big pharma doesn't want to compete with it. I also went from hypo to hyper while on Armor Thyroid. Did the compound of Levo and Lio thyroid meds but this is the only one that finally got my numbers into the normal range. I went to a regular doctor and she upped my dose of NP and blood pressure shot up from normal to 165/105! She denied the effect and wanted to put me on blood pressure meds but once my NMD readjusted it blood pressure went down.