Once-a-week AVONEX® (interferon beta-1a)

One injection, once a week

AVONEX is a once-weekly treatment for relapsing MS. Talk to your doctor to see if AVONEX may be right for you.

AVONEX dosing and administration

AVONEX is a 30 mcg intramuscular (into the muscle) injection and is available in one of two ways:


AVONEX PEN is a prefilled, single-dose autoinjector that lets you treat your relapsing MS in a single click. It includes a covered needle that's half the length of the standard needle for AVONEX prefilled syringe. 

AVONEX prefilled syringe

AVONEX prefilled syringe lets you inject your weekly dose of AVONEX by following a step-by-step process.

Before taking AVONEX

Before taking AVONEX, tell your healthcare provider about all of your medical conditions, including if you:

  • are being treated for a mental illness or had treatment in the past for any mental illness, including depression and suicidal behavior
  • have or had bleeding problems or blood clots
  • have or had low blood cell counts
  • have or had liver problems
  • have or had seizures (epilepsy)
  • have or had heart problems
  • have or had thyroid problems
  • have or had any kind of autoimmune disease (where the body’s immune system attacks the body’s own cells)
  • drink alcohol
  • have or have had an allergic reaction to rubber or latex. The tip cap of the AVONEX prefilled syringe and prefilled autoinjector Pen contain natural rubber latex
  • are pregnant or plan to become pregnant. It is not known if AVONEX can harm your unborn baby
  • are breastfeeding or plan to breastfeed. AVONEX may pass into your breastmilk. Talk with your healthcare provider about the best way to feed your baby if you take AVONEX

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

How should I use AVONEX?

The injection process and recommended injection sites are different for each of these options.

  • See the Instructions for Use for detailed instructions for preparing and injecting your dose of AVONEX
  • A healthcare provider should show you how to prepare and measure your dose of AVONEX and how to inject your AVONEX before you use AVONEX for the first time
  • A healthcare provider or nurse should watch the first AVONEX injection you give yourself
  • AVONEX is given once a week by injection into the muscle (intramuscular injection)
  • Inject AVONEX exactly as your healthcare provider tells you
  • A healthcare provider will tell you how much AVONEX to inject and how often to inject AVONEX. Do not inject more than your healthcare provider tells you to
  • Do not change your dose unless your healthcare provider tells you to
  • Change (rotate) the injection site you choose with each injection. This will help decrease the chance that you will have an injection-site reaction
  • Do not inject into an area of the body where the skin is irritated, reddened, bruised, infected or scarred in any way
  • AVONEX comes as a:
    • Prefilled syringe (can be used with the AVOSTARTGRIP® titration kit)
    • Single-Dose Prefilled Autoinjector Pen (AVONEX PEN®)
    • A healthcare provider will decide which one is best for you. See the Instructions for Use for detailed instructions for preparing and injecting your dose of AVONEX
  • After 2 hours, check your injection site for redness, swelling, or tenderness. If you have a skin reaction and it does not clear up in a few days, contact your healthcare provider
  • A healthcare provider will decide which one is best for you
  • Always use a new, unopened AVONEX prefilled syringe or single-dose prefilled autoinjector pen for each intramuscular injection
Ways to help manage flu-like symptoms

Most people experience flu-like symptoms when first beginning treatment with AVONEX. Usually, these symptoms last for a day after the injection. For many, these symptoms lessen or go away over time as their bodies adjust to AVONEX. 

During the start of your treatment, your healthcare provider may recommend you build up to a full dose of AVONEX gradually over the first month. This is a process called titration.

The recommended dose of AVONEX is 30 micrograms (30 mcg) once a week. To reduce the incidence and severity of flu-like symptoms that may occur at this dosing level, you may start taking AVONEX at a dose of 7.5 mcg. You may subsequently increase the dose by 7.5 mcg each week for the next three weeks until you reach the recommended dose of 30 mcg.

The AVOSTARTGRIP® Titration Kit, which is used with AVONEX prefilled syringes, can help you get started with titration. Once you have achieved the 30 mcg per week recommended dose you may also transition to the single-dose AVONEX PEN: a prefilled, single-dose autoinjector with a needle that is half the length of the AVONEX prefilled syringe.

Flu-like symptoms may include fever, chills, muscle aches, and tiredness. Experiencing flu-like symptoms doesn't mean you actually have the flu. These symptoms may be part of your body's natural response to interferon beta-1a. The following tips may help to manage flu-like symptoms:

  • Check mark IconStay well hydrated
  • Check mark IconAsk your healthcare provider about using over-the-counter pain and fever reducers on treatment days
  • Check mark IconExperiment with different times of day for your injection. Symptoms may peak at different times depending on the individual
  • Check mark IconKeep a journal to note how long after your injection any side effects occur, how much water you drink, and any pain relievers you take
  • Check mark IconIt's important to talk to a healthcare provider about any side effects you experience
Guidance for storing AVONEX
  • Store AVONEX in the refrigerator between 36°F to 46°F (2°C to 8°C)
  • Do not freeze AVONEX. Do not use AVONEX that has been frozen
  • If you cannot refrigerate your AVONEX PEN and AVONEX prefilled syringes, you can store your AVONEX PEN and AVONEX prefilled syringes at room temperature up to 77°F (25°C) for up to 7 days
  • Do not store AVONEX above 77°F (25°C). Do not use AVONEX that is stored at temperatures higher than 77°F (25°C).
  • Throw AVONEX away in an FDA-cleared sharps disposal container if it has not been stored as stated above
  • Keep AVONEX in the original carton to protect it from light
  • Do not use AVONEX past the expiration date
  • Keep AVONEX prefilled syringes, pens, and all other medicines out of the reach of children
  • Consider these storage requirements when traveling

AVONEX injection video

See how to prepare and to give an injection with AVONEX PEN