Swapping to Natural
Most of us try this at least once. We clear the resistance, get onto a stable dose of T3 and think "I wonder how I would feel back on Natural Dessicated Thyroid" (NT). I've tried it once, decided I was better on T3 only, and have decided to stay on "T3 only" long term.
In order to stand any chance of succeeding this needs to be done over a couple of months. You won't end up on the dose of Natural that you were on before going to T3, if things have worked right resistance will have cleared meaning you need less.
If you want to give it a go then the following process is recommended:-
Day 1, drop 10 (or 12.5) or T3 and replace it with 1 grain of Natural. This should have very little effect on the first day as the T3 content is virtually identical.
During the following week the T4 levels from that NT will build up and either start converting to T3 or RT3. If it goes the "right way" and starts converting to T3 you will end up feeling hyper (or less hypo) and by the end of that week be ready to drop another 10 of T3. If it goes to RT3 you may end up feeling more hypo by the end of the week. Taking your resting pulse and waking temperature each day while swapping over is strongly recommended. If they are going down you are getting hypo, if they go up you might need a reduction.
After a couple of weeks you should be fairly stable on that reduced dose of T3 and the grain of Natural. Once you feel stable then it is time to dtop another 10 (or 12.5) of T3, add another grain, and see which direction it goes in again. Once again if the T4 starts converting you will be ready to drop another 10 or so of T3 a week later.
Following this process over a few months will allow you to swap to NT if it works for you or find out early if it does not work. If it's working the benefit of the T4 will become aparent a week or so after adding each grain.
If it does not work then give up, swap back to T3 only, and stay on it long term.
See this link for a discussion on whether you need T4 at all.