PowerDrive has always been effective for me in early morning workouts. I wake up faster and am “tuned in.” However it has little benefit for me during evening workouts as I’m already “tuned in” and ready to crank. Another thing: It seems PowerDrive enhances the effect of T4 (or T3 I’m sure) dramatically. I add 100mcg of T4 per day in my “diet” and have seen general benefits as far as more energy and slow fat decrease (probably same to low dosing T3). Powerdrive is almost like ECA to me on T4 as the effects are very very noticeable.