I would like to interject just a moment about the synthroid. I too was die-hard Armour, because synthroid nearly killed me about 3 yrs ago. It was a vicious circle, couldn't produce t3 from t4(synthroid) due to vitamin def.(candida) and then couldn't replenish vits b/c of the low thyroid. It sucked. BUT recently, I requested to give synthroid/cytomel a try again. I think the Armour was creating an issue with mucus, due to leaky gut is all I can figure. I just know the stuff WAS NOT working anymore. I was taking 170mg a day, and still felt hypo.(I also have cortef. I don't take it all the time, plus it didn't really help much???) NOW, I take 100mg synthroid(not enough yet), and my gut is already responding better. It's been a long road, but I think I finally was able to replenish some of the nutrients necessary for proper thyroid conversion(thanks to Armour in the first place). But the leaky gut things messed all that up. Anyway, I'm grateful the synthroid and cytomel(very little). If you need to start somewhere, I think synthroid is worth a try. You might be able to convert better than someone else. We are all different. But you feeling like you can't take it anymore is more than likely a low thyroid symptom. Have you tried a doctor about it?