The imporatant thing is that you take it the same WAY (meaning on an empty stomach or not and with other pills or not) every day and at about the same time every day.

When you initially begin thyroid hormone replacement or change your dose, it takes about 8 weeks to reach the level in your blood that it will "stay" at (I'm sure there's a term for this.) After 8 weeks get your T4, T3 and TSH checked to see if this is the optimal dose for you. It may be that if you take it with food or other meds that interfere with its absorbtion, you will need a higher dose to make up for that.

Just be aware that if you stop taking it with food, or seperate from those other meds suddenly and start feeling hyperthyroid, that may be the reason and you may need a dose decrease.