Entyvio (vedolizumab) has been used for Crohn's disease and ulcerative colitis since 2014, and it is often chosen because it works mainly in the gut rather than throughout the body, which tends to mean fewer problems with infections than older biologics. Even so, people starting it want to know what to expect, and people on it want to know whether a new symptom is the medicine or the disease. This guide explains what the official label reports, which side effects are common and which are rare but serious, how Entyvio compares with other IBD biologics on safety, what happens when it does not work or stops working, and why people in that situation are exactly who clinical studies of new IBD treatments are looking for.
Entyvio not working well enough?
Studies are testing new treatments for Crohn's disease and ulcerative colitis in people whose current medicine has not worked, stopped working, or caused side effects.
How Entyvio works, and why its safety profile is different
Entyvio blocks a protein on white blood cells called alpha4beta7 integrin, which those cells use to travel into the lining of the intestine. By blocking it, Entyvio keeps inflammatory cells out of the gut without switching off the immune system elsewhere. That gut selectivity is the main reason its infection profile differs from TNF blockers such as Humira and Remicade, which act throughout the body. It is given as an intravenous infusion for the first doses and then either as infusions every eight weeks or as an injection under the skin every two weeks with the Entyvio Pen. Our guides cover ulcerative colitis treatment and Crohn's disease treatment more broadly.
The common side effects
In the trials used for approval, the most common side effects of intravenous Entyvio, reported by at least 3 percent of people and more often than placebo, were nasopharyngitis, meaning cold symptoms (13 percent versus 7 percent on placebo), headache (12 versus 11 percent), joint pain (12 versus 10 percent), nausea (9 versus 8 percent), fever (9 versus 7 percent), upper respiratory tract infection (7 versus 6 percent), and fatigue (6 versus 3 percent), followed by cough, bronchitis, flu, back pain, rash, itching, sinusitis, sore throat, and pain in the arms or legs. For most of these the difference from placebo is small, which is part of why Entyvio is considered well tolerated. With the under the skin injection, the side effects are similar, plus injection site reactions such as pain, swelling, redness, or itching.
Infusion and allergic reactions
About 4 percent of people in the trials had an infusion related reaction, compared with 3 percent on placebo: nausea, headache, itching, dizziness, fatigue, fever, hives, or vomiting, usually within the first two hours. Most were mild and managed by slowing the infusion. Serious allergic reactions, including anaphylaxis, have been reported and are rare; the label advises stopping Entyvio and treating if a serious reaction occurs. Infusions are given in a setting prepared for this, and you will usually be observed for a period afterward during the first doses.
Infections
Because Entyvio acts on the immune system, the label lists an increased risk of infections. In practice the infections seen more often than placebo were mostly upper respiratory, nose, and sinus infections, and 2 percent of people in the trials stopped Entyvio because of an infection. Serious infections were uncommon, at a rate close to placebo; the most frequent was an abscess near the anus in Crohn’s disease, which is also a complication of the disease itself, and rare cases of sepsis and tuberculosis have been reported. Entyvio is not started in someone with an active severe infection, and any infection that does not settle, or fever with chills, should be reported promptly.
The rare risks
Progressive multifocal leukoencephalopathy (PML). A rare brain infection seen with an older integrin blocker used for multiple sclerosis. No cases were seen in Entyvio's trials, and the label says the risk is unlikely but cannot be ruled out, so doctors watch for new neurological symptoms such as weakness on one side, vision changes, confusion, or personality changes.
Liver injury. Reported rarely; the label advises reporting fatigue, loss of appetite, right upper abdominal discomfort, dark urine, or yellowing of the skin or eyes.
Vaccines. Live vaccines are generally avoided during treatment, so it is worth updating vaccinations before starting, including flu and pneumonia vaccines.
How Entyvio compares with other IBD biologics on side effects
TNF blockers such as Humira, Remicade, and their biosimilars act on the whole immune system and carry higher rates of serious infections and some other risks; Stelara and the newer IL-23 blockers (Skyrizi, Omvoh) sit somewhere in between; JAK inhibitor pills such as Rinvoq have their own warnings about clots and infections. Entyvio's gut selective action generally puts it at the lower risk end for systemic infections, which is why it is often chosen for older adults or people with a history of infections. The trade off some people experience is a slower onset: it can take several months to judge the full effect.
When Entyvio is not working, or stops working
Two situations bring people to this page. The first is a slow start: Entyvio often takes longer than TNF blockers to show its full effect, and the label advises stopping it if there is no benefit by week 14, for both ulcerative colitis and Crohn’s disease, so that is when doctors usually decide whether it has worked. The second is loss of response after it worked well, which happens with every IBD biologic over time. Common next steps include checking drug levels, shortening the interval between doses, adding a different medicine, or switching to a biologic or pill that works through a different mechanism. Some people also stop because of side effects they cannot live with, even when the medicine is working. All of these situations, a medicine that has not controlled symptoms, one that stopped working, or one that caused side effects that required stopping, are exactly what current IBD research is built around.
How to find a Crohn's or ulcerative colitis study
AllClinicalTrials.com lists IBD studies recruiting across the US, and you can filter them by location before applying. Right now that includes studies of an investigational biologic for adults with Crohn's disease or ulcerative colitis whose current medicine has not worked well enough, stopped working, or caused side effects. The application takes about 5 minutes: you answer questions about your diagnosis, the medicines you have tried, and your current symptoms, and if a study near you looks like a match, the research team contacts you. Nothing is decided until you have gone through informed consent, and participation is voluntary at every step. More studies are on our Crohn's disease and ulcerative colitis pages.
Three things to have ready: your diagnosis (Crohn's or UC) and when it was made, the IBD medicines you have taken and why each one ended, and your current symptoms.
Common questions
What are the most common side effects of Entyvio? Cold symptoms (13 percent in trials versus 7 percent on placebo), headache, joint pain, nausea, fever, upper respiratory infections, and fatigue, followed by cough, bronchitis, flu, back pain, rash, itching, and sinusitis. With the injection, site reactions are also common.
Does Entyvio weaken your immune system? It acts on immune cells that travel to the gut, so it increases infection risk mainly in the gut and upper airways rather than throughout the body. That is why its infection profile is generally milder than TNF blockers, though any lasting infection should be reported.
What are the serious side effects of Entyvio? Serious infusion or allergic reactions, serious infections, liver injury, and a theoretical risk of the brain infection PML, which was not seen in trials. All are rare, and each has warning signs listed on the label.
How long does Entyvio take to work? Longer than some biologics. The label advises assessing response by week 14 for both ulcerative colitis and Crohn’s disease, and stopping if there is no benefit by then.
Can Entyvio stop working? Yes. Loss of response over time happens with all IBD biologics. Options include checking drug levels, shortening the dosing interval, adding a medicine, or switching mechanisms.
Does Entyvio cause fatigue or joint pain? Both are listed as common side effects, though they occurred only slightly more often than with placebo in trials, and both are also features of active IBD, so your doctor will consider which is the cause.
Can I join an IBD study if I am on Entyvio or stopped it? Studies of new treatments often enroll people whose current biologic is not working well or who stopped one because of side effects; switching is planned with the study team, and a washout period may be required. Each listing states its rules.
Do IBD trial participants get paid? Some studies offer compensation for time and travel, and study related care is typically provided at no cost to participants. Compensation varies by trial and is always described during the informed consent process before you agree to anything.