Re: synthroid alternative
It sounds as if you're experiencing an allergic reaction to the dye or filler in the tablet. A different brand might not cause the same problem. Many doctors are so stubbornly reluctant to prescribe anything other than Synthroid, that people run into this problem more often than the profession cares to admit.
It's also possible that you react badly to synthetic meds in general.
I also reacted badly to Synthroid... not with a rash, but with terrible joint and muscle pain and a total loss of appetite. The endo I was seeing prescribes nothing but Synthroid. Even after she reduced my dose twice, I eventually went hyper on it and she told me to discontinue the med and come back in 3 months. She offered no alternative to Synthroid. Within a month after stopping it, I was hypo again, but I didn't give her another chance. I began to see a doctor who prescribes natural dessicated med (Armour brand, in my case), and I'm doing fine on it. Doctors who rely on the natural Rx meds are rarer, but it's worth it to locate one who does. People most often do better on these meds than on synthetics.
When you ask about "natural supplements", I assume you mean over-the-counter kinds of things? If you have hypothyroidism caused by Hashimoto's disease, which is the most common cause, the OTC things likely will not help. If your hypoT is caused by a temporary condition or is extremely mild in nature, it's theoretically possible to bolster thyroid function using health food store supps. I don't know much about how to do that, though.