Thyroid UK
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Getting used to different T3 brands?

Sorry I keep asking questions!

I'm trying to swap from Grossman Cynomel to Tiromel. Even a much smaller dose of Tiromel is giving me a bit of an adrenaline surge after I take it. It isn't an allergy. I had the same symptoms but much worse with MercuryPharma liothyronine. I don't know if I'm absorbing more of it or it's going into my bloodstream faster.

Has anyone experienced what I'm experiencing?

Did you get used to the brand change after a while? i.e. you stopped being bothered by the adrenaline?

6 Replies

VitaminKgirl, have you tried splitting the Tiromel into smaller doses 3 or 4 times throughout the day?


The problem is I'm really sensitive to adrenaline.

I normally take 5 doses of 3-4mcg of Cynomel per day.

I tried to swap one of my doses to the same amount of MercuryPharma or Tiromel and had adrenaline problems and hyper type symptoms. MercuryPharma was worse than Tiromel. Just one dose a day was enough to give me horrible symptoms all day!

Even trying to take about 2mcg of Tiromel is causing me some problems with adrenaline, which I just don't understand. All I can think is I'm absorbing more of it or absorbing it faster.


VitaminKgirl, the only thing I can suggest is to try crushing the Tiromel to try a smaller dose and see whether it makes a difference. Perhaps taking it with food will slow absorption.


Hello Vitaminkgirl, I had the opposite response when I switched from Cynomel to Tiromel, which was that the Tiromel seems not to have been very effective! It just seems to be very individual when I look at other related questions and posts on the site, bests x


Yes, that's what makes this so confusing! I've heard of many people having the opposite reaction and finding Tiromel weaker than Cynomel, and only come across one person who seemed to find the opposite! Everyone seems to regard Cynomel as one of the strongest brands of T3. I wish I understood why I'm having the opposite experience!


Quick update! I seem to have found something I tolerate, maybe because it's supposed to be a slow-release formula, made with hypromellose instead of lactose as the release agent.

Perrigo (formerly Paddock) liothyronine. I have some 5mcg tablets I'm cutting in half (they are horrible to cut, they mostly shatter and crumble!) I'm finally starting to feel okay again, after days and days of weakness and shakes. Slow progress, I daren't subsitute more than one dose a day at the moment. I'll have a TSH test in a few weeks time to see what's changed.


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