I feel like it gives me a good pump when taken pre w/o. From what I've heard, it goes great with fats so I pair my epi dose with a fish oil supp. I take 50% 30min before workout, and 12 hrs before that. 11:30pm and 11:30am are my doses currently. Next week I'm bumping my dose and dosing 11:30am/5:30am/11:30pm. I'm not sure if it will affect sleep if taken right before bed, my last dose is 4hrs before bed- if anyone else wants to chime in on this