If you have had a significant weight gain this can cause problems w C or V. Take the C 4 hours before.
Curious why you say four hours?
During the week I'll take it an Hour and a half before go time and a little foreplay will get him going.
On a Saturday morning I also take it about an hour and a half before go time, the only difference is I don't eat anything before hand or drink any coffee because I don't want to get the urge to take a shit when I get there.
During the week I'll already would have had breakfast and lunch earlier in the day and take the C around 3:30pm and arrive at my destination around 5:00 - 5:15.