I've been using Cop for years now, and have forgotten a few times. Also, if I forget to get my prescription in time, and maybe there is a holiday so the chemist is closed, I have gone without for a week without noticing any difference.
I do believe that Cop is helping me. I havn't had a real relapse since I started.
You have to take Cop for a few months before it starts to work, so I suppose it stays in your body for a long time, and missing for a day or two doesn't matter.
Bibo ergo sum