I did lemtrada in dec 2019 and again dec 2020. Treatment was bumpy with adverse affects but the biggest one was developing hyperthyroidism. I went hyperthyroid the first time September 2020. It took a few months to see endo and by then my numbers were normalizing. I was mildly hyperthyroid and didn’t require any meds and had very minor symptoms. By March of 2021 I was in normal range.

September 2021 I went hyperthyroid again. This time it was severe with lots of symptoms. TSH was undetectable and I was diagnosed with graves in November. Methimazole was prescribed and I had just started taking it when my next lemtrada labs showed my TSH had risen to 18. I stopped methimazole at that point but my TSH skyrocketed over the next six weeks to 188. The hypo symptoms were also severe.

I was eventually put on levothyroxine but the dose for my weight wasn’t bringing up my numbers. It was increased several times over 2022, the highest was 150mcg which is a huge dose for my size. I was tested for celiac but that was negative. Since my numbers were so unstable they put me on synthroid in 2023 but starting in May my TSH was once again undetectable. The dose was lowered a couple of times to 112mcg which is what I’ve been taking for awhile now. I have been taking that 6 days a week for months averaging out to about 93mcg/day with no improvement in my tsh.

Yesterday my endo said she wants to try tapering me off synthroid completely. She wrote me a prescription for the next lower dose and the plan is to watch my labs and drop the dose every 6-8 weeks. She said she’s never treated a patient with a disease course quite like this and suspects it’s likely that others who did Lem might have a similar course. Lem has been in use over 10 years but it’s a less popular treatment and the data is still coming in for stuff like this. I know that since I was offered Lem and doing research on it the thyroid disease numbers have increased a lot. She’s probably right that there’s still a lot of unknowns about the long term effects from Lem (or any new MS med).

I’m really excited I might have a thyroid that has bounced back. I don’t think anyone thought that would happen. I’m also curious if anyone here has had a similar course with thyroid disease. Anyone?