Muscle weakness and fatigue occurred due to the same ratios and rapid changes in T3, iodine, and T4 discussed already, with the same time frames. The fatigue felt like I had just run a marathon and there was simply no aerobic capability left in my legs. My thigh muscles would also burn with the typical “lactic acid” buildup that occurs within a day or two after a hard work out. This “burning” feeling contributed to the burning neuropathy feeling. Weakness and burning might be mild initially, but would progress proportionately depending on how much T3 or iodine I had taken for how long, and again, the higher the ratio of T3:T4, the worse the symptoms. I could feel “tremoring” in my leg muscles due to the weakness, and at the height of these symptoms, I could barely stand or walk due to the weakness. My head would feel too heavy to support and I could barely lift it. Every muscle of my body was affected. Sometimes it felt like my breathing was shallow, like I couldn’t take a deep breath. My handwriting worsened considerably during these times due to the shakiness, making it difficult to write out checks, and any drawing or anything requiring fine motor control was out of the question. Backing off the T3 or Iodine would improve this symptom remarkably, so this was yet another symptom that guided me in my dosage and diet adjustments.