Betaseron for Treatment of Multiple Sclerosis

In This Article

Betaseron (interferon beta-1b) is an injectable drug that belongs to a class of medications known as disease-modifying treatments (DMTs). It is used for people with relapsing forms of multiple sclerosis. It's also approved for use in people who have experienced one MS event with MRI signs that are consistent with MS.

Betaseron has been on the market longer than any other DMT; it was approved by the U.S. Food and Drug Administration (FDA) in 1993. Here's what to know about how this drug works and what the common side effects are.

How It Works

As with other DMTs, Betaseron is thought to work by reducing inflammation. It modifies the immune response by prompting the production of fewer pro-inflammatory agents and more anti-inflammatory agents.

It may also prevent immune cells from crossing the blood-brain barrier, stopping them from reaching the neurons in the central nervous system.


Efficacy of Betaseron is about the same as for similar drugs (namely, Copaxone, Rebif, and Avonex), resulting in about one-third reduction in relapses when compared to a placebo over two years. There is evidence that the higher-dose interferons (Betaseron and Rebif) may be slightly more effective at preventing relapses and reducing lesions than the lower dose version (Avonex).


Betaseron provides the highest weekly dose of all interferons, at 250 micrograms (mcg) per dose, given every other day (14 times per month). It comes with a titration schedule, meaning patients start at a small dose and increase gradually, which can reduce side effects.

It is delivered via a subcutaneous injection (meaning that it is injected into the fat right under the skin), as opposed to Avonex, which is injected into the muscle. Betaseron's neutral pH allows injections to be less painful than subcutaneous Rebif injections, due to that drug's high acidity.

The needle used for Betaseron injections is shorter than for intramuscular therapies (half an inch versus 1 to 1.25 inches) and is 27 gauge, which is pretty thin. A Betaject 3 automatic injecting device is provided.

Side Effects

The side effects of Betaseron are similar to those of other interferon-based therapies, with the exception of Avonex, which doesn't cause as many injection-site reactions.

Common side effects include:

  • Flu-like symptoms: These include fever, chills, sweating, muscle aches, and fatigue, which generally last for 24 to 36 hours. These are usually the worst after the first injection and progressively lessen with each injection; most people find the symptoms tolerable after six months. Taking ibuprofen or acetaminophen a couple of hours before and after can help.
  • Red spots: These usually occur at the site of injections and may last several weeks. In 4 percent of cases, the spots can become sores (injection-site necrosis). Rotating sites and placing a warm compress on a site prior to injecting can help reduce red spots. 
  • Liver damage: Elevated blood liver enzyme levels and hepatitis have been reported in patients on Betaseron.
  • Blood counts: Betaseron can cause a decrease in the numbers of red and white blood cells, as well as a reduction in the number of platelets in the blood.
  • Depression and seizures: Betaseron should be used with caution in patients with depression or seizures; these patients need extra monitoring.

While on Betaseron, blood tests need to be done every three months for the first year to check white blood cell count and liver function. After a year, they can be reduced to once every six months.

Safety During Pregnancy

Betaseron is a pregnancy category C drug, meaning it has been found to cause some harm to fetuses in animal studies, but the effect in humans is unknown. If you are planning a pregnancy, please inform your doctor right away so you can devise a plan together on when to stop using this drug.

Due to limited data to assess its safety in infants, Betaseron is generally avoided during breastfeeding. 


Betaseron is made by Bayer HealthCare Pharmaceuticals Inc. There is a patient support program called the BetaPlus Support Program. You can also call a nurse who can answer any questions at 1-844-788-1470.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Food and Drug Administration. Medication Guide: Betaseron.

  • National MS Society. Betaseron.