TSH shooting up to very high levels since starting T3

[disfrutarlo]

This isn’t about me, but my friend. I have a friend who was diagnosed with hashimoto’s disease in his early 20s. A cancerous tumor was then found on his thyroid and half of his thyroid was surgically removed. Ever since then he has been on complete replacement doses of thyroid medication, 100 mcg of T4. However ever since I have known him he demonstrated classic hypothyroid symptoms such as chronic fatigue, so I recommended him to try adding T3 to his regimen. He talked about it with his endocrinologist and he started taking 10mcg of t3 a day along with lowering his dose of T4 to 75mcg. It has made a huge effect on his mood, energy, he is obviously a lot healthier than he was before. However his TSH which was around 1 on T4 only first shot up to around 3 after a few months of taking T3 and is now around 9 after almost a year on T3. His free t3 and t4 are also still fairly low. To me he still seems somewhat hypothyroid but not nearly as bad as he was before starting t3. Does anyone know what could cause TSH levels to rise so absurdly high? I’ve never seen anyone with levels that high before. I’m worried that maybe the cancer has returned on the other half of his thyroid. He doesn’t have an appointment with his endocrinologist for another few months, does anyone know of any advice I could give him to help lower his TSH?

[Lejeboca]

@disfrutarlo. I happen to hear just now Ray saying that serotonin levels (stress) may raise TSH https://youtu.be/_NeCwCZYdWQ?t=1884 .

In general, TSH better reflects the thyroid hormone concentration in the pituitary than in cellular tissue. The following reference is illuminating about this and is replete with quotes on why TSH is a poor predictor of thyroid health: Thyroid Hormone Transport into Cellular Tissue.

To solve your friend's puzzle, I'd check his rT3, rT3/T3, and see whether he might have other comorbidities that may affect the pituitary health.