You may have to adjust the amount in the
syringe but you will not have to mix up the medication, put it into the
syringe, and then inject. I think the fewer steps involved, the less chance of error and also the less chance for contamination.
Hopefully they will teach you how to inject the Inteferon but here is a very good site that shows you how to use Pegasys Interferon), step by step. It never hurts to review the instructions even if they go over them with you in the office.
http://www.