I am taking 10mcg T3 every morning right now.
no idea what caused my high RT3 (was at 40 at one point), I think it was due to low ferritin/iron and low cortisol (my cortisol test results over the last three years range from 5.5 to 11 @ 8am when the ideal is > 15).
I was on 40mcg T3 daily at one point and had my RT3 down to 12, then I experienced an overall decline and new symptoms, so I cut back thinking I was overdosing on T3, but couldn't find the right balance, so I stopped both cortisol and T3... and my RT3 climbed back up (back to 27 - not as high as it use to be, but not good either).
I then started on the 10mcg T3 only in the morning and seem to be doing ok right now.... not great, but not terrible either.
I am also taking 10mg SR HC at night, and 5mg SR HC at 7am and 1pm. My saliva cortisol test showed my lowest level in the am. The HC disrupts my sleep slightly, so I am also taking 1-2mg Melatonin and I am sleeping great now.