Stelara works as an immunomodulator, which means it helps regulate the immune system. It is used to treat autoimmune conditions like Crohn's disease, where the immune system mistakenly attacks the body. Stelara aims to induce remission and prevent complications associated with the condition. However, it also suppresses the immune system, so precautions such as vaccinations and screenings for other health conditions may be necessary. It's important to discuss any concerns or questions with your healthcare provider.