Biologics for UC: Infusion vs Injection + How Doctors Pick a Class
Last Updated Jan 15, 2026
Ulcerative colitis is a form of inflammatory bowel disease (IBD) that causes swelling and sores in the lining of the colon. When symptoms are moderate to severe, or when flares keep coming back, many care teams discuss “advanced therapies,” including biologics for ulcerative colitis. A common decision point is how a medicine is given (infusion at a clinic vs injection at home) and which drug “class” best matches the situation.
Biologics and advanced therapies for ulcerative colitis (UC)
Biologics are protein-based medicines made in living cells. Many are antibodies that target specific parts of the immune system involved in inflammation. In UC, biologics are often grouped by what they block:
Anti-tumor necrosis factor (anti-TNF) medicines: These block tumor necrosis factor (TNF), a key inflammation signal. This group includes infusion and injection options.
Anti-integrin medicines: Vedolizumab (often called “vedolizumab UC” online) helps reduce gut inflammation by limiting immune cell “traffic” into the intestine.
Interleukin (IL) blockers: Ustekinumab (often searched as “ustekinumab UC”) targets IL-12 and IL-23, which are immune signals linked with inflammation.
Some newer UC treatments are not biologics, but are still considered advanced therapies. For example, Janus kinase (JAK) inhibitors are pills that change inflammation signaling inside immune cells (often searched as “JAK inhibitors UC”).
Another term that comes up in treatment decisions is biosimilars. A biosimilar is designed to be highly similar to an existing biologic, with no clinically meaningful differences in safety or how well it works, and it is taken the same way as the original medicine. [1]
Infusion vs injection: the practical differences (plus infusion day tips)
Infusions are given through an intravenous (IV) line at an infusion center, hospital clinic, or sometimes at home with trained support. Visits often include check-in questions about recent symptoms or infections, vital signs, and monitoring during the infusion and afterward, since reactions can happen with IV medicines. Infusions can feel simpler for people who prefer a nurse to handle dosing and scheduling, but they do require travel time and time in the chair.
Injections are usually “subcutaneous,” meaning the medicine goes under the skin using a prefilled syringe or auto-injector pen. After training, many people do injections at home. This can save travel time, but it also adds tasks like storing supplies and remembering doses.
Helpful, non-medical infusion day tips that many people use include wearing comfortable layers (easy IV access), bringing a phone charger, and planning something to pass the time (book, music, or work). It can also help to plan the day with extra buffer time, especially for early doses when clinics may monitor longer. [2]
How doctors pick a class and when treatment escalates
Gastroenterology teams usually match a medication to both the disease and the person’s needs. Factors can include how severe symptoms are, how quickly control is needed, past response to other medicines, other health conditions, and practical issues like comfort with injections vs clinic infusions.
Current guidelines also influence these choices. The American Gastroenterological Association (AGA) living guideline (updated November 19, 2024) groups multiple advanced therapies for moderate to severe UC by relative efficacy and supports using effective advanced options rather than relying only on a slow step-up approach after repeated treatment failures. [3]
Safety profile is part of class selection. Anti-TNF medicines can be very effective, but they are associated with risks such as serious infections (including tuberculosis) and certain cancers that have been reported, so clinicians often screen and monitor carefully. [4] Vedolizumab is offered as IV or injection, and common side effects can include headache, fatigue, and upper respiratory infections, with allergic reactions possible during or after an infusion. [5] Ustekinumab is commonly given as a one-time IV induction dose, followed by subcutaneous maintenance dosing every 8 weeks, which can appeal to people who want fewer ongoing doses. [6]
Finally, oral JAK inhibitors can be appealing because they are pills, but they come with important safety warnings. The United States Food and Drug Administration (FDA) requires warnings about increased risk of serious heart-related events, cancer, blood clots, and death for certain JAK inhibitors, and also limits use to certain patients who are not treated effectively with tumor necrosis factor (TNF) blockers or cannot tolerate them. [7]