Bimzelx (bimekizumab or bimekizumab-bkzx) is an injection that's used to treat several inflammatory conditions in adults. They include plaque psoriasis, psoriatic arthritis, and hidradenitis suppurativa, to name a few. It's a type of monoclonal antibody called an interleukin antagonist. It works to reduce inflammation in the body. Bimzelx (bimekizumab) comes in prefilled autoinjectors or prefilled syringes. You inject the medication under the skin either every month or every other month. Common side effects are upper respiratory infections.
Moderate-to-severe plaque psoriasis
Moderate-to-severe hidradenitis suppurativa
Bimzelx (bimekizumab) is a monoclonal antibody known as an interleukin antagonist. It blocks interleukin-17A and interleukin-17F (IL-17A, IL-17F). These are proteins in your immune system that play a role in causing inflammation (redness and swelling).
By blocking these proteins, Bimzelx (bimekizumab) calms down the immune system. This helps ease symptoms of certain inflammatory conditions.
Source: DailyMed
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Dosing schedule is either every month or every other month, so it's convenient for most people
An option for plaque psoriasis if topical medications have stopped working
Available as prefilled autoinjectors and prefilled syringes
Can cause injection reactions, such as pain, bruising, and swelling
Might raise the risk of infections
Unknown if safe during pregnancy or while breastfeeding
Keep Bimzelx (bimekizumab) in the refrigerator in its original box and away from light. Don't let it freeze. Throw the medication away if it's past the expiration date on the box.
You can also keep Bimzelx (bimekizumab) in its box at room temperature (up to 77°F) for up to 30 days. Don't place it back in the refrigerator once it's at room temperature. Don't use it after 30 days at room temperature.
The area where you inject Bimzelx (bimekizumab) might get red, swollen, or warm a couple hours afterwards. These reactions usually go away on their own in about 1 to 2 days. You can try using an ice pack wrapped in a towel to help. If it gets worse or doesn't go away, talk to your care team.
Before getting any vaccines, tell the healthcare professional you're taking Bimzelx (bimekizumab). They'll check if the vaccine is safe for you. It's not clear how this medication affects how well vaccines work or how safe they are for you. But it's best to avoid live vaccines during treatment to be safe.
Tips on how to take Bimzelx (bimekizumab)
Make sure you understand and are comfortable with how to inject Bimzelx (bimekizumab) before doing it yourself. Your healthcare professional will show you how to inject it your first time. Ask your care team if you have questions.
Check with your prescriber about when to inject Bimzelx (bimekizumab). Your dosing schedule depends on what you're using the medication for.
Before injecting Bimzelx (bimekizumab): Take it out of the refrigerator and let it come to room temperature. This should take about 30 to 45 minutes. Don't microwave, run hot water over it, or leave it in direct sunlight. Then, wash your hands with soap and water and clean the injection area with an alcohol swab.
Where to inject Bimzelx (bimekizumab): Inject the medication under the skin of the belly or thigh. You can also inject it into the back of your upper arm with someone's help. Don't inject into bruised, red, tender, or hard skin. Choose a different spot for each injection to avoid skin irritation.
For the Bimzelx (bimekizumab) prefilled syringes: Carefully pull the needle cap off the syringe. Gently pinch and hold a section of skin. Then, insert the needle into the skin at a 45-degree angle. Slowly push the plunger down until all the medication in the syringe is gone and you feel a little resistance. Then, let go of the plunger. The needle will move back into the needle shield by itself.
For the Bimzelx (bimekizumab) prefilled autoinjectors: Take off the cap, place the pen straight against your skin (at a 90-degree angle), and press down. When the injection starts, you'll hear a click and the window on the pen will start to turn yellow. Keep holding it against your skin until the window is all yellow and you hear another click. This means your injection is done (should take about 15 seconds).
Throw away all used autoinjectors, syringes, and needle caps into a sharps container. You can visit the FDA website to learn more about how to throw your sharps away safely to avoid needle-stick injuries.
Bimzelx (bimekizumab) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk factors: History of depression | History of suicidal thoughts or behavior | Taking other medications that affect mood
Some people who took Bimzelx (bimekizumab) had suicidal thoughts or behavior during studies. But it's not too common. Tell your prescriber if you've ever had serious depression or suicidal thoughts. They'll help decide if this medication is safe for you.
Watch for signs of depression or any unusual changes in mood or behavior while taking Bimzelx (bimekizumab). Let your prescriber know if you notice anything concerning. If you or someone close to you notices suicidal thoughts or behavior, call 911 right away.
Risk factors: Active, chronic (long-term), or recurrent infection | History of active or latent tuberculosis (TB)
Bimzelx (bimekizumab) can make it harder for your body to fight infections. This can raise your risk of infections, including tuberculosis (TB). These infections can also include sinus infections, fungal infections, stomach infections, and herpes. Serious infections were rare in studies.
Before you start Bimzelx (bimekizumab), talk to your prescriber about your medical history. Don't start the medication if you're sick or if you get infections often. Your prescriber will also check you for TB before starting. If you have latent TB, you might need to take antibiotics to help keep it from becoming active during treatment.
Tell your prescriber right away if you have any signs of an infection while taking Bimzelx (bimekizumab). Look out for signs like fever, chills, cough, sore throat, weakness, or night sweats.
Risk factors: History of liver problems
Rarely, people taking Bimzelx (bimekizumab) can have higher liver test results. This can sometimes be a sign of liver injury. Because of this, people with liver problems, such as cirrhosis, should avoid this medication.
Before starting Bimzelx (bimekizumab), you'll need blood tests done to check your liver. Your prescriber will also ask you to get more blood tests done during treatment to make sure you stay safe. Tell your prescriber right away if you have signs of liver damage. This includes pain in the upper right side of your stomach, yellow skin or eyes, or dark urine. If you show signs of liver damage, your prescriber might tell you to stop taking Bimzelx (bimekizumab).
Some people taking Bimzelx (bimekizumab) have had symptoms of inflammatory bowel disease (IBD). Before you start treatment, tell your prescriber if you have IBD. This medication might not be right for you.
Talk to your prescriber if you have symptoms of IBD while taking Bimzelx (bimekizumab). Look out for stomach pain, bloody stools, changes in bathroom habits (like having diarrhea or constipation), or losing weight suddenly. Your prescriber will check for IBD and help you figure out what to do next.
Risk factors: Getting live vaccines
Before starting Bimzelx (bimekizumab), talk to a healthcare professional about your vaccine history. They'll help make sure you're up to date.
We don't fully know how Bimzelx (bimekizumab) affects vaccines. But it might make some vaccines work less well. It could also raise the risk of infection from live vaccines themselves. So, it's best to avoid getting any live vaccines, like MMR (measles, mumps, and rubella vaccine), while taking Bimzelx (bimekizumab).
Plaque psoriasis
Starting dose for adults: Inject 320 mg under the skin every 4 weeks for 16 weeks. Then, continue with maintenance treatment.
Maintenance dose for adults: Inject 320 mg under the skin every 8 weeks. For people weighing 264 lbs or more, you might need to inject every 4 weeks instead.
Psoriatic arthritis, non-radiographic axial spondyloarthritis, or ankylosing spondylitis
Adults: Inject 160 mg under the skin every 4 weeks.
Hidradenitis suppurativa
Starting dose for adults: Inject 320 mg under the skin every 2 weeks for 16 weeks. Then, continue with maintenance treatment.
Maintenance dose for adults: Inject 320 mg under the skin every 4 weeks.
Moderate-to-severe plaque psoriasis
Moderate-to-severe hidradenitis suppurativa
Moderate-to-severe plaque psoriasis in people ages 6 years and older
Psoriatic arthritis (PsA) in adults
Ankylosing spondylitis (AS) in adults
Non-radiographic axial spondyloarthritis (nr-axSpA) in adults
Plaque psoriasis (PsO) in people ages 6 years and older
Psoriatic arthritis (PsA) in people ages 2 years and older who weigh at least 33 lbs
Ankylosing spondylitis (AS) in adults
Non-radiographic axial spondyloarthritis (nr-axSpA) in adults
Enthesitis-related arthritis in people ages 4 years and older who weigh at least 33 lbs
Hidradenitis suppurativa in adults
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Camiña-Conforto, G., et al. (2023). Bimekizumab in the treatment of plaque psoriasis: Focus on patient selection and perspectives. Patient Preference and Adherence.
Centers for Disease Control and Prevention. (2025). Clinical overview of latent tuberculosis infection.
Kuwabara, T., et al. (2017). The role of IL-17 and related cytokines in inflammatory autoimmune diseases. Mediators of Inflammation.
UCB, Inc. (2024). Instructions for use: Bimzelx® (bim zel’ ex) (bimekizumab-bkzx) injection, for subcutaneous use - 160 mg/1 mL single-dose autoinjector.
UCB, Inc. (2024). Instructions for use: Bimzelx® (bim zel’ ex) (bimekizumab-bkzx) injection, for subcutaneous use - 160 mg/1 mL single-dose prefilled syringe.
UCB, Inc. (2025). Bimzelx- bimekizumab injection, solution [package insert]. DailyMed.
U.S. Food and Drug Administration. (2021). Safely using sharps (needles and syringes) at home, at work and on travel.
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