Starjemza
Starjemza (ustekinumab or ustekinumab-hmny) is a biologic medication that's a biosimilar to Stelara (ustekinumab). As a biosimilar, it’s approved to treat the same autoimmune conditions, including plaque psoriasis, psoriatic arthritis, Crohn's disease, and ulcerative colitis. It works by blocking certain proteins called interleukins that cause inflammation in the body. The medication is usually given as an injection under the skin, with doses every 8 to 12 weeks. Common side effects include feeling tired, having a headache, or experiencing common cold symptoms.
What is Starjemza (ustekinumab)?
What is Starjemza (ustekinumab) used for?
- Moderate-to-severe plaque psoriasis (Ps) - adults and children 6 years and older
- Psoriatic arthritis (PsA) - adults and children 6 years and older
- Moderate-to-severe Crohn's disease (CD) - adults only
- Moderate-to-severe ulcerative colitis (UC) - adults only
How Starjemza (ustekinumab) works
Starjemza (ustekinumab) is an interleukin antagonist. It works by blocking two proteins in your immune system — interleukin-12 (IL-12) and interleukin-23 (IL-23) — that play a major role in inflammation. By targeting these proteins, the medication helps to lower inflammation and relieve symptoms from autoimmune conditions.
Drug facts
Side effects of Starjemza (ustekinumab)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
Plaque psoriasis
- Common cold symptoms (7-8%)
- Upper respiratory tract infection (4-5%)
- Headache (5%)
Psoriatic arthritis
- Joint pain (3%)
- Nausea (3%)
Crohn's disease
- Common cold symptoms (11%)
- Redness at the injection site (5%)
- Yeast infection (5%)
- Bronchitis (5%)
Ulcerative colitis:
- Common cold symptoms (24%)
- Headache (10%)
- Stomach pain (7%)
- Flu infection (6%)
- Fever (5%)
Less Common Side Effects
- Dizziness
- Diarrhea
- Back pain
- Muscle pain
- Depression
- Sore throat
- Itchiness
- Vomiting
Starjemza (ustekinumab) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Serious infection: fever, muscle aches, cough, trouble breathing, weight loss, sores on the body, diarrhea, stomach pain, problems with urination, tiredness
- Severe allergic reaction: feeling faint, facial swelling, chest tightness, rash
- Brain condition: headache, confusion, vision problems, seizures
- Lung conditions: trouble breathing, cough
The following Starjemza (ustekinumab) side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Change in your skin, such as a new growth, a sore that doesn't heal, or a change in a mole
- Dry cough, shortness of breath or trouble breathing
- Infection—fever, chills, cough, sore throat, wounds that don't heal, pain or trouble when passing urine, general feeling of discomfort or being unwell
- Sudden and severe headache, confusion, change in vision, seizures, which may be signs of posterior reversible encephalopathy syndrome (PRES)
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
- Diarrhea
- Dizziness
- Fatigue
- Headache
- Pain, redness, or irritation at injection site
- Runny or stuffy nose
- Sore throat
Get your GoodRx coupon
Pros and cons of Starjemza (ustekinumab)
Pros
- Biosimilar that's interchangeable with Stelara (ustekinumab)
- Syringes can be stored at room temperature for up to 30 days
- Approved for children as young as 6 years old for certain conditions
- After the first few doses, only need a shot every 8 to 12 weeks
Cons
- Can weaken your immune system and raise your risk of infection
- Potential to cause serious allergic reactions
- For CD and UC, the first dose must be given as an IV infusion
- Can't receive live vaccines while taking this medication
Pharmacist tips for Starjemza (ustekinumab)
- Mark your injection dates on a calendar. You don’t use Starjemza (ustekinumab) very often, so it can be easy to forget. Keeping track helps you stay on schedule.
- Inject Starjemza (ustekinumab) under the skin in your upper arms, thighs, buttocks, or stomach area. Pick a new spot each time to avoid skin irritation. Don’t inject into skin that’s red, bruised, sore, or hard.
- Get medical help right away if you have signs of a serious allergic reaction after using Starjemza (ustekinumab). These might include swelling of the face or throat, trouble breathing, or a rash.
- Starjemza (ustekinumab) can weaken your immune system, making it harder to fight infections. Let your prescriber know if you have symptoms of an infection, such as a fever, cough, tiredness, muscle aches, or stomach pain.
- Contact your care team right away if you notice symptoms like headache, confusion, vision problems, or seizures. These could be signs of a rare brain condition linked to Starjemza (ustekinumab).
- Starjemza (ustekinumab) can affect how your body responds to vaccines. Avoid live vaccines during treatment. Talk to your prescriber before getting any type of vaccine.
- Store Starjemza (ustekinumab) in its original carton in the refrigerator. If you're using the prefilled syringes or 45 mg vial, you can keep them at room temperature (up to 30°C or 86°F) for up to 30 days, but don’t put them back once they've been out of the fridge.
How to inject Starjemza (ustekinumab) from a prefilled syringe:
- Make sure you know how to inject Starjemza (ustekinumab) the right way. Ask your prescriber or pharmacist if you have questions.
- Check the dose on the syringe before giving the injection. If you need to use two syringes for your dose, be sure to inject each syringe into a different spot.
- Clean the spot on your skin with an alcohol wipe before you inject to help prevent infection.
- When you're ready to inject, take off the needle cover from the syringe. Hold the syringe with one hand and pinch the cleaned skin with the other.
- Insert the needle into the pinched skin at about a 45-degree angle and push the plunger down with your thumb until all the liquid is injected. Then take out the needle and let go of your skin.
- Put the syringe into a sharps container. Never throw used syringes into the regular trash since it could harm someone.
Common questions about Starjemza (ustekinumab)
Starjemza (ustekinumab) has been available in the United States since November 2025. It was approved by the FDA in May 2025.
No. Starjemza (ustekinumab) isn’t exactly the same as Stelara (ustekinumab), but it’s very close. It’s a biosimilar, meaning it works the same way in the body and is just as safe and effective. Both medications have the same active ingredient, ustekinumab, and are used to treat the same conditions. Even if they look different, they’re made to have the same overall effect. Talk to your prescriber if you have questions comparing both medications.
Yes. Starjemza (ustekinumab) is interchangeable with Stelara (ustekinumab). That means that pharmacies can substitute Starjemza (ustekinumab) for Stelara (ustekinumab) without a new prescription. It can make switching easier and more convenient if you want to switch medications.
You can stay on Starjemza (ustekinumab) as long as it works well for you and doesn’t cause any serious problems. Your prescriber will check regularly to make sure the treatment is still helping and safe to continue.
How to save using GoodRx
Risks and warnings for Starjemza (ustekinumab)
Starjemza (ustekinumab) 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.
Infections
- Risk factors: Active, chronic, or recurrent infection | People with certain genetic mutations | Taking other medications that weaken your immune system
Starjemza (ustekinumab) can raise your risk of infections, including serious ones that might need hospital care. These can be caused by bacteria, viruses, or fungi. Tell your prescriber about your medical history before starting Starjemza (ustekinumab), especially if you've ever had tuberculosis (TB). Let your care team know right away if you have signs of infection, such as fever, chills, cough, or tiredness — your treatment might need to be paused until you recover.
Cancers
- Risk factors: Older adults | Taking other medications that weaken your immune system | History of skin cancer
Starjemza (ustekinumab) weakens your immune system and can raise your risk of certain cancers. Some people developed skin cancer while taking this medication, especially those with a higher risk. Your care team will check your skin regularly during treatment, particularly if you have a history of cancer or other risk factors. Let your prescriber know if you’ve had cancer before or if you notice any new or changing spots on your skin.
Severe allergic reaction
Serious allergic reactions, including anaphylaxis and angioedema, have been reported with Starjemza (ustekinumab). If you have a severe reaction, your care team will stop the medication and treat you right away. Get medical help immediately if you have symptoms like trouble breathing, swelling of your face or throat, or a serious rash.
Brain condition
Rare cases of a brain condition called posterior reversible encephalopathy syndrome (PRES) have been reported in people taking Starjemza (ustekinumab). Symptoms can include headache, seizures, confusion, or vision changes. These symptoms can appear anywhere from a few days to months after starting the medication, sometimes even after a year or more. If you have PRES, your care team will stop the medication and provide treatment. Let your prescriber know right away if you notice any of these signs.
Vaccines
Before starting Starjemza (ustekinumab), you or your child should be up to date on all recommended vaccines. While you're being treated, avoid getting live vaccines. You should also avoid the BCG vaccine during treatment, as well as for one year before starting and one year after stopping the medication. Be careful if someone in your household gets a live vaccine since it can spread and pose a risk to you. Non-live vaccines are generally safe, but they might not work as well while you're taking Starjemza (ustekinumab). Check with your care team before getting any vaccines during treatment.
Lung problems
Different types of pneumonia have been reported in people taking Starjemza (ustekinumab), and in some cases, these conditions were serious. Symptoms can include cough and trouble breathing. Let your care team know right away if you have new or worsening breathing problems. You might have to stop taking the medication and receive the appropriate treatment.
Starjemza (ustekinumab) dosage
Typical dosage for Starjemza (ustekinumab)
Plaque psoriasis
- Adults:
- Weight 220 lbs or less: The typical dose is 45 mg injected under the skin once, then another 45 mg four weeks later. After the second dose, 45 mg is injected every 12 weeks.
- Weight more than 220 lbs: The typical dose is 90 mg injected under the skin once, then another 90 mg four weeks later. After the second dose, 90 mg is injected every 12 weeks.
- Children ages 6 and older:
- Weight less than 132 lbs: The typical dose is 0.75 mg/kg of body weight injected under the skin once, then another 0.75 mg/kg four weeks later. After the second dose, 0.75 mg/kg is injected every 12 weeks.
- Weight of 132 lbs to 220 lbs: The typical dose is 45 mg injected under the skin once, then another 45 mg four weeks later. After the second dose, 45 mg is injected every 12 weeks.
- Weight more than 220 lbs: The typical dose is 90 mg injected under the skin once, then another 90 mg four weeks later. After the second dose, 90 mg is injected every 12 weeks.
Psoriatic arthritis
- Adults:
- Psoriatic arthritis only: The typical dose is 45 mg injected under the skin once, then another 45 mg four weeks later. After the second dose, 45 mg is injected every 12 weeks.
- Psoriatic arthritis with plaque psoriasis and weighing more than 220 lbs: The typical dose is 90 mg injected under the skin once, then another 90 mg four weeks later. After the second dose, 90 mg is injected every 12 weeks.
- Children ages 6 and older:
- Weight less than 132 lbs: The typical dose is 0.75 mg/kg of body weight injected under the skin once, then another 0.75 mg/kg four weeks later. After the second dose, 0.75 mg/kg is injected every 12 weeks.
- Weight of 132 lbs or more: The typical dose is 45 mg injected under the skin once, then another 45 mg four weeks later. After the second dose, 45 mg is injected every 12 weeks.
- Psoriatic arthritis with plaque psoriasis and weighing more than 220 lbs: The typical dose is 90 mg injected under the skin once, then another 90 mg four weeks later. After the second dose, 90 mg is injected every 12 weeks.
Crohn's disease and ulcerative colitis:
- Adults:
- Weight less than 121 lbs: The typical dose is 260 mg infused into the veins once, then 90 mg injected under the skin every 8 weeks.
- Weight of 121 lbs to 187 lbs: The typical dose is 390 mg infused into the veins once, then 90 mg injected under the skin every 8 weeks.
- Weight more than 187 lbs: The typical dose is 520 mg infused into the veins once, then 90 mg injected under the skin every 8 weeks.
How much does Starjemza (ustekinumab) cost?
$419.05
What are alternatives to Starjemza (ustekinumab)?
Starjemza (ustekinumab) images
