I had thyroid cancer approx 10 years ago. I have been through the generics, name brands, multiple doses schedules during the week, combinations of synthroid and cytomel. I was getting my thyroid blood work checked every 8-12 weeks for most of that time
I learned that for me name brand worked much better than generic. Even when I felt "best" on a certain dosing regime, it's still nothing like having your own native thyroid gland producing thyroid hormone that your body recognizes. The biggest lie hat was told to me as that " all I'd have to do was to take synthroid and I'd feel better.
Also I experienced wide fluctuations in my thyroid levels despite being on the same dose of synthroid and cytomel ( a T3 drug bc I discovered I didn't convert synthroid which is a T4 replacement). I've read later that the makers of synthroid had issues with keeping quality control within proper standards)
Finally after 10 years of " no active disease" I asked my endo to give me Armour thyroid. Armour has T4and T 3 in it as it is derived from pigs. I definitely feel better than when I was on synthroid/cytomel combo. But it's still not like having your own thyroid hormone.
Many people told me that thyroid cancer was the good cancer. But most people even endos don't realize the extent of what not having a thyroid does to you and your family. I have experienced fatigue so great that it just can't be explained, brain fog,weight gain despite my best efforts in the gym several times a week, hair loss, edema that's just the hypothyroid part. When I slip into hyperthyroidism there's the restless to no sleep, easily agitated, panic attacks, high anxiety, and still extreme fatigue
Part of the treatment for thyroid cancer is to keep your TSH down ( hyperthyroid) to suppress remnant thyroid tissue regrowth I had surgery and radioactive iodine. Oh and there were/ are lively side effects from being radioactive for a week that I still deal with