I was taking 3 tabs of Thyroid-S, which improved symptoms but not enough. When I took more that 3 grains I got palpitations. To get help with Chronic Fatigue, I followed my Dr's advice and went back to Levo thyroxin - 150mcg, which I feel no good on. Because it's marginally cheaper, I was thinking of buying T3 from a stockist in Greece to supplement the T4 in Levo.. Some kind person on here told me that 3 grains of Thyroid S is equivalent to 27mcg of T3 - cant remember how much T4 is in it without looking it up. Perhaps the content of T3 in thyroid S is not as consistent as the synthetic version.. Does anyone have any thoughts on this? The synthetic T3 comes in 25mcg tablets.