You're on the right track with the Ear Temp thing. I've got a fair bit of experience with T3. More than I'd like, because it took forever to get it right. T3 seems to be the most fickle thing I've ever used.
IME, it takes a lot more T3 to burn fat than 25mcg. 25mcg will just quickly leave you with less than you'd normally produce. The first few days, it seems like it's working, because it's on top of your normal production. After that, you're guessing.
What worked? This. Anything less than this and I'd skip it. Got this from an overseas board (where I live) It's a pretty commonly used protocol based on body temp. I've also posted it over at AnaSci.
BTW, SHBG is known to be a hormone transporter nowadays IIRC, not the evil stopper of gains it was once thought to be.
Anyway, T3:
""1. take your morning temp (in ear thermometer) before leaving bed 5 mornings in a row..
2. start your t3 use, 50-100mcg/day
3. keep measuring your temp.
4. after 5 days if your temp is not 0.3-0.6 higher, (so, from 98.6 to between 99.1 and 99.6 for non metric folks) take another 25mcg, if not higher in another 5 days, take another 25mcg. Most shouldn't need more than 150mcg total.
5. keep measuring your temp.
6. when your temp drops 0.6deg 3xmornings in a row- is the temp lower than when you started? if not you have just started to down regulate your own production.
Stop and you will have no rebound; if its lower than when you started, you will have a little rebound, unless you keep your diet tight- keep measuring, and when your temp goes back to your baseline, your thyroid has recovered full function.
Run it 2 days on 2 days off and have not had a temp drop in over 6 months...
if you run daily, you will lose fat faster, but may get a temp drop and some rebound. your choice.""
Hope this helps someone.