Yes, Ginny, you have to have a script. My vet called mine in too. That's the only way she does it, she won't sell it directly from the clinic.
I found the people I dealt with at VPA to be really great. The 2nd time I called for some, they read all my info back to me before I could say anything other than my name. They even had the script as belonging to "Bob Berube" instead of Carl. Unfortunately, Bob has crappy credit, so I had to use my card...
Carl