Risankizumab, sold under the brand name Skyrizi, is an injectable biologic medication used to treat moderate-to-severe plaque psoriasis in adults who may need systemic therapy or phototherapy. It works by blocking interleukin-23, an inflammatory protein involved in the immune response that drives psoriasis. Risankizumab may be a good option for people with widespread, stubborn, or severe psoriasis that has not improved enough with topical treatments or light therapy. It is given as a subcutaneous injection, with starter doses followed by maintenance dosing every 12 weeks. Because it affects the immune system, clinicians usually screen for infections such as tuberculosis before starting treatment. Possible side effects include upper respiratory infections, headache, fatigue, injection-site reactions, and increased risk of infection.