Before i used the product i had zero joint/muscle pain. I used the product for 4 weeks as prescribed and then stopped. A few days later I had debilitating joint/muscle pain. I mean from my toes to my fingers, shins,forearms, muscles. Everything. It was bad for about 4 weeks then tapered off. Never fully got pain free. Through out the entire time i thought no way it could be this product. I read up on hypothyroidism and those were symptoms. I still thought it was unlikely but had no other reason so decided to go back on and see what happens. The pains pretty much went away within a few days. I have no real evidence , I should of got bloodowork done immediately and see what's goin on but again I doubted it was this OTC product. I'm going to buy NOW thyroid support, coleus and see what happens. If the pain doesn't go away I'm scheduling a docs appt. I switched jobs and had to wait 90 days for my new insurance kicks in so figured id try some natural stuff before I go to the doc. Could be not related, could have had a pre existing condition etc. But it def seems thyroid /tr33 related, as odd and rare tnat it