Bimzelx (bimekizumab) and Tremfya (guselkumab) are both injectable medications used to treat moderate-to-severe plaque psoriasis, psoriatic arthritis, and other conditions. They are both monoclonal antibodies, but they work differently. Bimzelx is an interleukin antagonist that blocks interleukin-17A (IL-17A) and interleukin-17F (IL-17F), while Tremfya targets interleukin-23 (IL-23). Tremfya is also approved for treating ulcerative colitis and Crohn's disease, whereas Bimzelx is approved for treating non-radiographic axial spondyloarthritis, ankylosing spondylitis, and hidradenitis suppurativa. Bimzelx is typically injected every month at first, then every other month, while Tremfya is injected once at the start, again at week 4, and then every 8 weeks. Bimzelx is available as prefilled autoinjectors and syringes, whereas Tremfya offers a prefilled syringe or a patient-controlled injector. Both medications can cause injection site reactions and increase the risk of infections. Both should be used with caution if you have a history of infections or liver issues.