I've been doing a lot of reading and thinking on this lately. It's pretty obvious, if you look at the thyroid bb's, that there are a lot of people who feel sub-optimal on their thyroid meds. Part of the problem, I think, is an over-reliance on the TSH test by doctors - so much so that if your TSH is "normal", then they say any hypothyroid symptoms you have must be due to something else - even when they are OBVIOUS symptoms of hypothyroidism.
I had high-dose RAI for Graves which pretty much wiped out my thyroid so you and I are in a similar boat. Some things for us to consider:
- standard medical dogma is that the T4 in your Synthroid will be converted at normal rates into T3 in your cells. This probably works well for most people, but there are clearly some people out there who do not convert T4 to T3 well. Next time you have bloodwork done, ask for a Free T4 AND a Free T3. If the T3 is in the lower end of the normal range, you might be someone who isn't converting well.
Normally, your thyroid releases 90% T4 and 10% T3, so it is normal to have some T3 being released directly into your bloodstream from the thyroid. In my case, and yours, we don't have that, so we may be more likely to need T3 (even though T3 should be being made from T4 at the cellular level).
I have been on a combination of Levothroid and Cytomel (T3) for about 8 months now - I've noticed some improvement in the brain fog but nothing else earth-shattering. I'm a little disappointed, actually, but perhaps the problem is my total dose not being high enough (although my TSH is 1), so I have bumped my T4 up a little.
- iron deficiency or selenium deficiency can affect utilization of the thyroid hormones. You should think about having a ferritin level checked (to make sure you are not someone with a tendency to store too much iron - hemochromatosis) then consider an iron supplement to bring it into the upper end of the normal range. Selenium supplements may help with T4-T3 conversion and decrease thyroid antibodies - but again, too much can be toxic, no more than one tablet a day or just eat a few Brazil nuts every week.
- some people say they do better on Armour thyroid (which is made from pig glands and contains 20% T3, as well as possibly other components from pig gland that we don't know what they do). I always had a few older patients who just couldn't tolerate switching from Armour to T4. Some people don't do well with it, though, and it can be hard to find a doctor who will prescribe it. I'm thinking about trying it, though, if this last dose increase doesn't help. Armour should be taken twice a day because T3 has a short half-life, and some people recommend starting lower and working up to an equivalent dose.
- people on the boards argue for shooting for a replacement level that gets your Free T4 and Free T3 into the upper third of the normal range. I don't know how well this correlates with clinical outcomes but it seems a reasonable goal to try for. I think doctors are so afraid of overdosing patients on thyroid hormone that they leave far too many underdosed.
