Does Testosterone Replacement Affect the Thyroid?

I feel TRT did increase my T3, but it would be difficult to prove.

I think it did that because I was taking 0.75 grains of NDT, (45mg), and my T3 went up from 2.8 > 4.2 ng/dl. That is a pretty large gain for a small dose.

I stopped taking NDT for a while, and will retest at some point in the near future.

Of course, even if my T3 is higher than 2.8 ng/dl, it could have been some other factor than the testosterone.
I switched from SubQ to IM injection of test, and I really think TRT effected my Thyroid, or maybe I should say it is normalizing everything again. After several months being on NP 60mg with my FT3 at 4.5 and still hypo symptomatic, going IM made me having hyperthyroidism symptoms, mixed with hypo. I had to cut in half my NP thyroid last week, and things seems to normalize again. It would have been curious to check on t3 levels then. I will keep the 30mg NP daily and check levels in 10 days and see how I feel