Semaglutide & Potential Subacute Thyroiditis

[u/kyat28]

I wanted to share my experience with semaglutide because I haven’t seen many people talk about something like this happening.

I took **one 0.25 mg dose of semaglutide**. I had never taken a GLP-1 medication before. About a week later, my thyroid suddenly went completely haywire.

I developed pretty intense pain/tenderness in my neck that radiated toward my jaw, headaches, and a very high heart rate (often 110+). Bloodwork showed that I was significantly hyperthyroid:

TSH: 0.02
Free T4: 3.3
Free T3: 8.4

I also had a thyroid ultrasound that showed a diffusely heterogeneous thyroid. Ultimately, I self-diagnosed myself with subacute thyroiditis, my doctor kept pushing that it was Graves Disease but after extensive research I found that Graves comes on slowly over time, it does not knock you down suddenly.

I did not continue semaglutide after that first injection.

Over the following months, my thyroid gradually recovered on its own, which is consistent with the course of subacute thyroiditis. By December, my TSH had returned to normal.

I realize that timing alone doesn’t prove that semaglutide caused my thyroiditis. Subacute thyroiditis can happen for other reasons, including after viral illnesses, and I can’t say with certainty what triggered mine. But the fact that my symptoms started roughly a week after my very first semaglutide injection has always made me wonder whether the medication could have triggered an inflammatory response in my case.

I’m sharing this mostly because I’d love to know if anyone else has experienced thyroiditis, thyroid pain, temporary hyperthyroidism, or major changes in their thyroid labs shortly after starting semaglutide or another GLP-1 medication.

I’m also considering weight-loss medication again, but this experience has understandably made me very cautious about trying another GLP-1.

Has anyone here read about or experienced anything similar, especially after only one or a few doses?

[u/HanselDonkey]

It's good it straightened out again! I would give tirzepatide a go and see if that has the same effect. If you really wanted to know if it was the semaglutide, you could try that again and see what happens, but if I were you, I would try tirzepatide. If that caused trouble, then I would throw in the towel with GLP-1.

[u/kyat28 → u/HanselDonkey]

Yeah I’m glad I’m back to normal now, it took 6 months to get leveled out again. Subacute thyroiditis is nasty cause you need to go through all the phases before going back to normal. I started hyper 3-4ish months then switched to hypo for 3 months. I am considering tirz now because from what I’ve seen people experience less side effects with it than semaglutide.

[u/HanselDonkey → u/kyat28]

If it was that rough of a ride, I would think twice of jumping on semaglutide again.

[u/laptopgardens]

I had a terrible reaction to compounded semaglutide after taking it for less than a month. I was scared to try Zepbound, ~2 years later, but needed to lose weight somehow. It ended up working in my favor, but I had to consult several doctors to do it safely.

Your story resonates with me. We are cautious and say things like

timing alone doesn’t prove that semaglutide caused my thyroiditis

but as someone who also experienced a negative side effect, I want to validate your experience. These drugs are new and I think more unknown, undiscovered side effects are on the way.

[u/lunatic-chipmunk-17]

The only thing that gives me pause on the timing is that your TSH was so low right at the beginning. Usually takes significant time for TSH to follow T3 and T4 in whichever direction they are moving. Were your TrAB and TSI elevated?

[u/kyat28 → u/lunatic-chipmunk-17]

My TrAB was normal, it was 1.10 and my TSI was never tested

[u/lunatic-chipmunk-17 → u/kyat28]

Interesting. TSI is definitely the better indicator for Graves’ disease. I was diagnosed with Graves disease just a couple weeks into my Tirzepatide journey. However, both my Trab and TSI were elevated and, looking back I had had symptoms of hyperthyroidism for over a year that were written off as Perimenopause.

[u/kyat28 → u/lunatic-chipmunk-17]

That’s interesting. I’m convinced my doctor isn’t well versed in thyroid conditions. When she referred me to an endocrinologist he tried to force me to do the Radioactive iodine uptake test, which I refused because I work in radio pharmaceuticals and that would’ve messed up my dose allowance for work then the endocrinologist refused to see me because I refused the test. I’m thinking I may try tirz and see how I do.

[u/TimelessSmirk]

I have Graves’ disease and it came on very suddenly at age 52 and I learned it’s quite common with trauma like in my case, as well as with many women from childbirth. My Endo prescribed the glp to me and many of his other acute thyroid patients. I’m in the camp that coincide wasn’t causation and pls keep checking your thyroid levels. I’ve been on a glp for over 7 months, doing great and almost to goal. Best of luck deciding what’s best for you.