What is Stelara? Stelara is an immunosuppressant that reduces the effects of a chemical substance in the body that can cause inflammation. Stelara is used in adults to treat plaque psoriasis or psoriatic arthritis.

Stelara side effects may include:

  • cold symptoms such as stuffy nose, sneezing, sore throat
  • headache, tired feeling
  • mild diarrhea
  • mild skin rash or itching