By some reason it feels so. Even if it's still in the blood its effects wear out pretty quickly.
Many endocrinologists prescribe only 5 mcg tabs so you can easily split the (low) daily dose, unlike the old 25 mcg tabs.
They advise 3 times a day because it's easier to remember as most people make 3 meals a day.
Doctors advise to split the dose as much as possible because they are scared to be sued as too much T3 too quickly can cause palpitations high blood pressure and even stroke or heart attacks.
Unlike T4, T3 has a pretty good absorption no matter if taken with meals or not.
I'd rather 4 a times a day because it's easier to split the powder in 4 parts.
The problem is that it is a powder. Not only cumbersome but cops can think it's a recreational drug.
I'd buy some empty caps and pour 1/4 of the powder in each.
Don't take SEVERAL 75 mcg caps in the same day. At least not in the beginning. You can land in the hospital in the very first day.