Stelara (ustekinumab) is a prescription medicine used to treat adults with psoriasis. 

Stelara belongs to a group of drugs known as monoclonal antibodies. It works by binding to specific proteins of the body that are involved in inflammation and immune response, thereby preventing these proteins from binding to other cells and causing the symptoms of psoriasis.

Stelara comes as a solution to inject under the skin by a nurse or doctor. It is usually given in a doctor's office every 4 weeks for the first two doses and then every 12 weeks.

Some common side effects of Stelara include upper respiratory infections, headache and tiredness.