In aromatherapy can you use more than one essential oil synergistic blend at the same time . . . . . . .?

with out losing the theutic effects of either blend. Of course common sense dictates that using a relaxant and a stimulant at the same time would be a waste of time. But like today I made mage oils containing synergistic essential oil blends. One is for treating depression and the other is for treating fatigue. Can I use both at the same time without losing the theutic effects of either blend? Forgive me it that is a dumb question. I am new to aromatherapy.