Synthroid fillers/binders/dyes include acacia, confectioner’s sugar (contains corn starch), lactose
monohydrate, magnesium stearate, povidone, and talc. Some of the color additives include FD&C Yellow No. 6 (in 25 mcg tablets), FD&C Red No. 40 and FD&C Blue No. 2 (in 75mcg strength), etc.
If you are having reactions to Synthroid, you might just want first to switch to another brand which has different fillers/binders. What type of reactions are you having?