Crohn’s disease causes inflammation, swelling, and irritation in the lining of the digestive tract.

If you’ve tried other treatments for Crohn’s disease, or even if you’re newly diagnosed, your doctor may consider prescribing biologic drugs. Biologics are prescription drugs that help reduce harmful inflammation from Crohn’s disease.

Biologics are genetically engineered medicines that target certain molecules in the body involved in causing inflammation.

Doctors often prescribe biologics to those with refractory Crohn’s disease that isn’t responding to other medications, or to people with severe symptoms. Before biologics, there were few nonsurgical treatment options for people with refractory disease.

Biologic drugs work to quickly bring on remission. During a period of remission, inflammation and intestinal symptoms go away. Biologics may also be used on a long-term basis to help maintain periods of remission.

The type of biologic your doctor suggests will depend on the severity of your symptoms and the location of disease. Everyone is different. A certain biological drug may work better for some than others. You may have to try a few medications before finding what works for you.

Biological therapies for Crohn’s disease fall into one of three categories: anti-tumor necrosis factor (anti-TNF) therapies, interleukin inhibitors, and anti-integrin antibodies.

Anti-TNF therapies target a protein that’s involved in inflammation. For Crohn’s disease, anti-TNF therapies work by blocking inflammation caused by this protein in the intestines.

Interleukin inhibitors work similarly, by blocking naturally occurring proteins that cause inflammation in the intestines. Anti-integrins block certain immune system cells that cause inflammation.

Biologics are typically given either subcutaneously (with a needle through the skin) or intravenously (through an IV tube). They may be given every two to eight weeks, depending on the medication. You’ll have to go to a hospital or clinic for most of these treatments.

The FDA has approved several biological drugs to treat Crohn’s disease.

Anti-TNF medications

  • adalimumab (Humira, Exemptia)
  • certolizumab pegol (Cimzia)
  • infliximab (Remicade, Remsima, Inflectra)

Interleukin inhibitors

Anti-integrin antibodies

  • natalizumab (Tysabri)
  • vedolizumab (Entyvio)

Biologic therapies can be a powerful tool in the treatment and management of Crohn’s disease. There are two different approaches to biologic therapy:

  • Step-up therapy was the conventional approach until new guidelines were released in 2018. This approach means that you and your doctor try several other treatments before starting a biologic.
  • Top-down therapy means that biologic medications are started much earlier in the treatment process. This is now the preferred approach in many cases of moderate to severe Crohn’s disease.

However, different approaches may work better for different people depending on the severity and location of the disease.

Biologics tend to have fewer side effects that are less harsh than other Crohn’s disease medications, such as corticosteroids, which suppress the entire immune system.

Still, there are certain side effects you should know about before taking a biologic medicine.

Some common side effects of biologics include:

  • redness, itching, bruising, pain, or swelling around the injection site
  • headache
  • fever or chills
  • difficulty breathing
  • low blood pressure
  • hives or rash
  • stomach pain
  • back pain
  • nausea
  • cough or sore throat

Biologics may not be safe for everyone. Talk to your doctor if you have tuberculosis (TB), are prone to infections, or have a heart condition.


Biologic drugs used for Crohn’s disease can increase the risk of reactivating a tuberculosis infection in people who have been exposed. TB is a serious, infectious lung disease.

Your doctor should test you for TB before starting therapy with a biologic. A TB infection can be dormant in the body. Some people who’ve been exposed to the disease might not know it.

If you’ve had prior exposure to TB, your doctor may recommend TB treatment before taking a biologic.


Biologics can lower the body’s ability to fight other infections. If you’re prone to infections, your doctor may suggest a different type of therapy.

Heart conditions

Anti-TNF medications may be risky for people with certain heart conditions, such as heart failure. Heart failure is when the heart can’t pump enough blood to meet the body’s needs.

Tell your doctor as soon as possible if you experience shortness of breath or swelling of the feet while taking a biologic for Crohn’s disease. These may be signs of heart failure.

Other issues

Biologic therapies have occasionally been linked with serious health problems. In people taking biologic drugs, the following health problems are rarely reported:

  • certain blood disorders (bruising, bleeding)
  • neurological problems (including, numbness, weakness, tingling, or visual disturbances, such as blurred vision, double vision, or partial blindness)
  • lymphoma
  • liver damage
  • severe allergic reactions

Talk with your doctor to determine the best therapy for you and your needs.