The half life of T3 is roughly 10hrs. Twice daily dosing makes good sense and most progressive endos will prescribe it that way. Start of with 25mcg upon waking and 25mcg 1/2hr before dinner. I'd caution against any T3 use without AAS. It's easy to eat up muscle along with that fat.
i take one dosage right when i wake up before ingesting anything. i keep the dosage low so i can run it longer like during the summer. im normally running test along with it and stack clen 2 weeks on 2 weeks off as well