T4 Levothyroxine
 

T4 is pro-hormone, which your body converts into T3 at necessary rate only and thus it could be considered as much milder and safer drug than T3.

It is recommended that levothyroxine be taken with an empty stomach approximately half an hour to an hour before meals to maximize its absorption.

Cycle lengths 4-5 weeks.
Most people start with 25mcg.