Key takeaways
Tremfya (guselkumab) and Stelara (ustekinumab) are both injectable medications used to treat autoimmune conditions like plaque psoriasis and psoriatic arthritis. Tremfya specifically targets the protein interleukin-23 (IL-23) to reduce inflammation, while Stelara blocks both interleukin-12 (IL-12) and IL-23. Stelara is also approved for treating Crohn's disease and ulcerative colitis, which Tremfya is not. The dosing schedules differ: Tremfya is injected every 8 weeks after the initial doses, whereas Stelara is injected every 12 weeks after the initial doses. Stelara can be used in children as young as 6 years old, while Tremfya is only for adults. Both medications can raise your risk of infections and have similar side effects like headaches and injection site reactions, but Stelara also has a rare risk of causing a condition called posterior reversible encephalopathy syndrome (PRES).
