I too had some recent weight gain, brain fog, terrible libido, etc, so I had my
thyroid labs done. All the numbers looked good, and close to optimal, except for my reverse T3, which was slightly higher than the top range. This could be due to stress, inflammation, or poor thyroid function. My trt clinic put me on 25mcg/day of T3 for a month, with no change. Then upped it to 50mcg/day for a few weeks, also with no symptom relief. I slowly titrated back down and am now on 1 grain of NatureThroid, and still don't feel any different. The entire time I didn't notice any change in symptoms (fat loss, libido, ed), except I may have had a bit more energy, or maybe it was just a placebo effect, because it was barely noticeable.
To make a long story short, thyroid levels had nothing to do with my problems. I was hoping it was the missing piece, but I'm back to searching for answers. Hopefully you find some answers, and keep us posted!