L-Citrulline is my go to per-workout and it has a window of about 1-2 hours after a 45 minute uptake. So if you take 3 in the morning and 3 pre workout, you might only get the benefit of the 3 pre-workout depending on when you exercise. The morning dose will be finished with it's benefits by lunch.
Now, you could do a split in the morning and at lunch on non-workout days to sustain a benefit during the workday to feel a bit better.
