Guselkumab Injection
Guselkumab is an injectable biologic medication used to treat moderate-to-severe plaque psoriasis, active psoriatic arthritis, moderately to severely active ulcerative colitis, and moderately to severely active Crohn's disease.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Guselkumab Injection: Patient Information Guide
A plain-language walkthrough of Guselkumab Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Guselkumab injection (brand name Tremfya) is a biologic medication approved to treat several immune-driven inflammatory conditions:
- Moderate-to-severe plaque psoriasis: Tremfya is approved for adults and children 6 years of age and older who also weigh at least 40 kg, when systemic therapy or phototherapy is appropriate.
- Active psoriatic arthritis: Tremfya is approved for adults and children 6 years of age and older who also weigh at least 40 kg. It can be used alone or with a conventional disease-modifying antirheumatic drug (DMARD) such as methotrexate.
- Moderately to severely active ulcerative colitis: Tremfya is approved for adults only. It is not established for use in children with this condition.
- Moderately to severely active Crohn's disease: Tremfya is approved for adults only. It is not established for use in children with this condition.
⚙️How it works▾
Guselkumab is a monoclonal antibody — a highly targeted, lab-engineered protein — that specifically locks onto a molecule called IL-23 (interleukin-23). IL-23 is a naturally occurring immune signaling protein that, when overactive, drives the inflammation behind psoriasis, psoriatic arthritis, ulcerative colitis, and Crohn's disease. By blocking IL-23 from docking with its receptor, guselkumab reduces the release of pro-inflammatory chemicals (cytokines and chemokines) that cause skin plaques, joint swelling, and gut inflammation.
💊How it's taken▾
Tremfya is given by injection — either under the skin (subcutaneous) or, in certain cases at the start of treatment, directly into a vein (intravenous infusion) in a clinic or hospital. The dosing schedule depends on the condition being treated and the phase of treatment:
- For plaque psoriasis and psoriatic arthritis (adults and eligible children): Tremfya is given as a subcutaneous injection at the start, again a few weeks later, and then every 8 weeks on an ongoing basis.
- For ulcerative colitis and Crohn's disease (adults only): Treatment begins with an induction phase — either by IV infusion or subcutaneous injection given three times over the first several weeks — followed by a maintenance phase of subcutaneous injections every 4 or 8 weeks. Your doctor will choose the lowest effective dose to maintain your response.
If you miss a dose, give it as soon as you remember, then return to your regular schedule. There are no food restrictions with this medication.
🤒Side effects — in detail▾
Most people tolerate Tremfya well. The most commonly reported side effects include:
- Upper respiratory infections (cold, runny nose, sore throat)
- Headache
- Injection site reactions (redness, bruising, swelling, itching, or pain)
- Joint pain (arthralgia)
- Diarrhea
- Gastroenteritis (stomach or intestinal infection)
- Bronchitis (in people treated for psoriatic arthritis)
- Fatigue and fever (particularly in people treated for ulcerative colitis or Crohn's disease)
Serious reactions — including severe infections, TB reactivation, liver injury, and anaphylaxis (a life-threatening allergic reaction) — are less common but require immediate medical attention. Contact your doctor or go to an emergency room if you experience difficulty breathing, chest tightness, yellowing of the skin, severe abdominal pain, or signs of serious infection like high fever.
⚠️Warnings & precautions▾
- Serious infections: Tremfya lowers immune defenses, which can allow bacterial, viral, or fungal infections to take hold. Do not start treatment during an active significant infection. Tell your doctor immediately if you develop fever, chills, cough, or other infection signs during treatment.
- Tuberculosis (TB): All patients must be screened for TB before starting Tremfya. Latent (inactive) TB must be treated before beginning Tremfya. Two cases of active TB were reported in Crohn's disease trials. Your doctor will monitor you for TB symptoms throughout treatment.
- Liver injury (hepatotoxicity): Serious liver injury has been reported. For ulcerative colitis and Crohn's disease, liver enzymes are checked before and during treatment. Seek medical care immediately if you notice yellowing of the skin or eyes, dark urine, or severe nausea.
- Serious allergic reactions: Anaphylaxis (a severe, potentially life-threatening allergic reaction) has been reported. If this occurs, Tremfya must be stopped and emergency treatment given right away.
- Live vaccines: Avoid all live vaccines while on Tremfya. Get all recommended, age-appropriate vaccines before starting treatment.
🔀What it interacts with▾
Tremfya has a limited but important drug interaction profile. Here's what to be aware of:
- Medications processed by liver enzymes (CYP450 substrates): Inflammation can alter how the liver processes certain drugs. When Tremfya reduces inflammation, it may change blood levels of drugs broken down by CYP3A4, CYP2C9, CYP2C19, CYP1A2, and possibly CYP2D6 enzymes. If you take any medication with a narrow safe range — meaning a small change in blood level matters — your doctor or pharmacist should monitor you closely when starting Tremfya.
- Live vaccines: Combining Tremfya with live vaccines may increase infection risk. Avoid live vaccines during treatment and ensure your vaccine schedule is complete before starting.
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Serious allergy to guselkumab: Tremfya is contraindicated (must not be used) if you have had a serious allergic reaction to guselkumab or any of its inactive ingredients.
- Active infections: Do not start Tremfya if you have a clinically significant active infection. Tell your doctor about any chronic infections or history of recurring infections.
- Tuberculosis: You must be tested for TB before starting. Latent TB requires treatment before Tremfya is initiated.
- Liver disease: If you have signs of acute liver disease or cirrhosis, your doctor should consider other treatment options. Liver tests are required before starting treatment for ulcerative colitis or Crohn's disease.
- Pregnancy: Limited data exist on Tremfya use during pregnancy. Because monoclonal antibodies cross the placenta, babies exposed in the womb may carry the drug at birth. A pregnancy registry is available — ask your doctor or visit www.mothertobaby.org/ongoing-study/tremfya-guselkumab.
- Breastfeeding: It is unknown whether guselkumab passes into human breast milk. Discuss the risks and benefits with your doctor.
- Children: Tremfya is approved for children 6 years and older (weighing at least 40 kg) for plaque psoriasis and psoriatic arthritis only. It has not been established for use in children with ulcerative colitis or Crohn's disease.
- Older adults (65+): No dose adjustment is needed based on age. Clinical studies did not find meaningful differences in how the drug behaves in older adults.
📡Pharmacodynamics — effects in the body▾
In people with plaque psoriasis, guselkumab measurably reduced blood levels of inflammatory proteins — including IL-17A, IL-17F, and IL-22 — compared to levels before treatment. In people with psoriatic arthritis, it also lowered markers of acute inflammation such as C-reactive protein, serum amyloid A, and IL-6, with reductions visible as early as Week 4. These changes reflect the drug's dampening effect on the overactive immune signaling that causes symptoms, though the exact link between these laboratory markers and clinical improvement is not fully understood.
🔬Pharmacokinetics — how your body processes it▾
After a subcutaneous injection, guselkumab is absorbed gradually, reaching peak blood levels in about 5.5 days, with an estimated bioavailability (the fraction that reaches the bloodstream) of about 49%. The drug has a half-life of approximately 15 to 18 days, meaning it takes several weeks to fully clear the body. Guselkumab is not processed through the usual liver enzyme pathways; instead, like other antibody-based drugs, it is broken down into small peptides and amino acids by the body's natural protein-recycling processes. Clearance increases with body weight, but this does not require a dose adjustment. No meaningful differences in clearance were seen in older adults or in studies comparing adults and eligible pediatric patients with plaque psoriasis.
📦How to store it▾
Store in a refrigerator between 2 ºC to 8 ºC (36 ºF to 46 ºF). Store in original carton until time of use. Protect from light until use.
📄 Written from Guselkumab Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
Supplements & herbs that interact with Guselkumab Injection
53 supplements and herbal products have documented interactions with Guselkumab Injection in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Moderate · 52
- Minor · 1
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Guselkumab Injection — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly does Tremfya treat, and is it right for me? ▾
How do I give myself the injection at home? ▾
What side effects should I expect, and when should I call my doctor? ▾
Do I need to worry about TB or other infections before I start? ▾
Is Tremfya safe to use during pregnancy or while breastfeeding? ▾
I take other medications — can I still use Tremfya? ▾
Is Guselkumab Injection available over the counter? ▾
When was Guselkumab Injection first available? ▾
💬 Answers drafted from Guselkumab Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Guselkumab Injection comes
Guselkumab Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Injection
How this form is used
- Tremfya subcutaneous injection is used to treat moderate-to-severe plaque psoriasis in adults and children 6 years and older weighing at least 40 kg
- Tremfya subcutaneous injection is used to treat active psoriatic arthritis in adults and children 6 years and older weighing at least 40 kg
- Tremfya intravenous infusion is used as the initial (induction) treatment for moderately to severely active ulcerative colitis or Crohn's disease in adults, followed by subcutaneous injections for ongoing maintenance
- Tremfya subcutaneous injection may also be used as an alternative induction option for ulcerative colitis and Crohn's disease in adults
- Tremfya subcutaneous injections are given into the front of the thighs or lower abdomen (avoiding 2 inches around the navel); the back of the upper arms is also an option for adults using the prefilled syringe
- Tremfya intravenous infusion for ulcerative colitis or Crohn's disease must be diluted and administered by a healthcare professional over at least one hour using an in-line filter
- Tremfya prefilled pens, One-Press injectors, and prefilled syringes are each for single use only — discard after one injection
- Remove Tremfya from the refrigerator and allow it to reach room temperature (up to 30 minutes) before injecting; do not inject into skin that is red, tender, bruised, or affected by psoriasis
📊 Guselkumab Injection across the U.S. market
How Guselkumab Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
📈 How widely Guselkumab Injection is used
A general measure of how commonly Guselkumab Injection is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Guselkumab Injection is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Guselkumab Injection prescribed? Of the 1,596 medications we measure, Guselkumab Injection ranks #725 by Medicaid prescriptions — more than 55% of them.
Utilization by Guselkumab Injection product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
1 ML guselkumab 100 MG/ML Auto-Injector Most dispensed
Summed across the 2 of 4 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2118739
1 ML guselkumab 100 MG/ML Prefilled Syringe
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1928686
2 ML guselkumab 100 MG/ML Auto-Injector
Summed across the 1 of 4 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2693094
20 ML guselkumab 10 MG/ML Injection
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2693088
2 ML guselkumab 100 MG/ML Prefilled Syringe
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2693096
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Guselkumab Injection, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 6 of 14 listed Guselkumab Injection NDCs with Medicaid activity.
🔍 Compare Guselkumab Injection products
A representative set of FDA-listed product records for Guselkumab Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 100 mg/mL | Subcutaneous | Janssen Biotech, Inc. × 3 listings | BLA | View NDC → |
| 200 mg/2 mL | Subcutaneous | Janssen Biotech, Inc. | BLA | View NDC → |
| 200 mg/20 mL | Intravenous | Janssen Biotech, Inc. | BLA | View NDC → |
Showing 5 of 5 products — FDA National Drug Code Directory. See every product, package size and price: browse all 5 Guselkumab Injection NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Guselkumab Injection — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Guselkumab Injection in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Guselkumab Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 1928588 3 dose forms · 5 strengths
-
Dose form (SCDF) Auto-Injector RxCUI 2118738In current FDA listingsClinical drug / strength (SCD) 1 ML guselkumab 100 MG/MLRxCUI 21187392 ML guselkumab 100 MG/MLRxCUI 2693094 -
Dose form (SCDF) Injection RxCUI 2693087In current FDA listingsClinical drug / strength (SCD) 20 ML guselkumab 10 MG/MLRxCUI 2693088 -
Dose form (SCDF) Prefilled Syringe RxCUI 1928685No current FDA listingClinical drug / strength (SCD) 1 ML guselkumab 100 MG/MLRxCUI 19286862 ML guselkumab 100 MG/MLRxCUI 2693096
Look up RxCUI 1928588 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Guselkumab Injection is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Guselkumab Injection belongs to the Interleukin-23 Antagonist class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Janssen Biotech, Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.