You should take Avonex exactly as directed by your doctor. Typically, this will be once a week by intramuscular injection. It is recommended that you have a partner to administer the injections as instructed by a doctor or nurse. Avonex comes as a liquid in a pre-filled syringe and as a powder in a vial. Pre-filled syringes need to be refrigerated, but should be at room temperature before administering the injection. Powdered Avonex needs to be reconstituted with sterile diluent, and should be used immediately after reconstitution.