Guselkumab: uses, dosing, side effects & brands
Guselkumab is a medicine sold in the U.S. under one brand, for psoriasis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Treats
- Psoriasis
- Available as
- Injectable
- Sold as
- Tremfya
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
How guselkumab is dosed
From the FDA label for Tremfya (application BLA761061). Other guselkumab products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
For the treatment of ulcerative colitis or Crohn's disease: Obtain liver enzymes and bilirubin levels prior to initiating treatment with TREMFYA. ( 2.1 , 5.4 ). For the treatment of plaque psoriasis or psoriatic arthritis, if clinically indicated, evaluate liver enzymes and bilirubin at baseline prior to initiating treatment with TREMFYA ( 2.1 , 5.4 ). Complete all age-appropriate vaccinations as recommended by current immunization guidelines prior to treatment initiation. ( 2.1 ) Recommended Dosage Plaque Psoriasis Adults 100 mg administered by subcutaneous injection at Week 0, Week 4, and every 8 weeks thereafter. ( 2.2 ) Pediatric Patients 6 Years of Age and Older Who Also Weigh at Least 40 kg 100 mg administered by subcutaneous injection at Week 0, Week 4, and every 8 weeks thereafter. ( 2.2 ) Psoriatic Arthritis Adults 100 mg administered by subcutaneous injection at Week 0, Week 4, and every 8 weeks thereafter. TREMFYA can be used alone or in combination with a conventional DMARD (e.g., methotrexate). ( 2.3 ) Pediatric Patients 6 Years of Age and Older Who Also Weigh at Least 40 kg 100 mg administered by subcutaneous injection at Week 0, Week 4, and every 8 weeks thereafter. TREMFYA may be administered alone or in combination with a conventional disease-modifying antirheumatic drug (e.g., methotrexate). ( 2.3 ) Ulcerative Colitis and Crohn's Disease Induction : 200 mg…
Guselkumab side effects
The following adverse reactions are discussed in greater detail in other sections of labeling: Hypersensitivity Reactions [see Contraindications (4) and Warnings and Precautions (5.1) ] Infections [see Warnings and Precautions (5.2) ] Tuberculosis [see Warnings and Precautions (5.3) ] Hepatotoxicity [see Warnings and Precautions (5.4) ] Most common adverse reactions associated with TREMFYA are: Plaque Psoriasis and Psoriatic Arthritis (≥1%): upper respiratory infections, headache, injection site reactions, arthralgia, bronchitis, diarrhea, gastroenteritis, tinea infections, and herpes simplex infections. ( 6.1 ) Ulcerative Colitis (≥3%) : injection site reactions, arthralgia, upper respiratory tract infections, headache, gastroenteritis, fatigue, pyrexia, and rash. ( 6.1 ) Crohn's Disease (≥3%) : respiratory tract infections, abdominal pain, injection site reactions, headache, fatigue, arthralgia, diarrhea, and gastroenteritis. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Janssen Biotech, Inc. at 1-800-526-7736 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse…
Who shouldn’t take guselkumab
TREMFYA is contraindicated in patients with a history of serious hypersensitivity reaction to guselkumab or to any of the excipients [see Warnings and Precautions (5.1) ] . History of serious hypersensitivity reactions to guselkumab or to any of the excipients. ( 4 )
Guselkumab drug interactions
7.1 CYP450 Substrates The formation of CYP450 enzymes can be altered by increased levels of certain cytokines (e.g., IL-1, IL-6, IL-10, TNFα, interferon) during chronic inflammation. Results from an exploratory drug-drug interaction trial in subjects with moderate-to-severe plaque psoriasis suggested a low potential for clinically relevant drug interactions for drugs metabolized by CYP3A4, CYP2C9, CYP2C19 and CYP1A2 but the interaction potential cannot be ruled out for drugs metabolized by CYP2D6. However, the results were highly variable because of the limited number of subjects in the trial. Upon initiation of TREMFYA in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect or drug concentration and consider dosage adjustment as needed [see Clinical Pharmacology (12.3) ] .
Every guselkumab product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Tremfya.
Guselkumab and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for guselkumab: levels in milk, effects in breastfed infants, and the drugs it would consider insteadNo information is available on the clinical use of guselkumab during breastfeeding. Because guselkumab is a large protein molecule with a molecular weight of about 144,000 Da, the amount in milk is likely to be very low. It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal. Some expert guidelines consider guselkumab to be acceptable during breastfeeding. Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.
National Institute of Child Health and Human Development, record revised December 15, 2025. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about guselkumab
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 1,920 reports naming guselkumab, and the FDA flagged 33% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- device deployment issue586 reports
- needle issue234 reports
- device issue159 reports
- device defective143 reports
- psoriasis105 reports
- device leakage97 reports
- psoriatic arthropathy58 reports
- injection site pain55 reports
Read these as a signal, not a rate. A report does not mean guselkumab caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
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Frequently asked questions
What is guselkumab?
Tremfya (Guselkumab) is a medication used to treat Psoriasis.
Can you take guselkumab with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run guselkumab against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does guselkumab come in?
Across the brands we track, guselkumab is currently marketed as injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic guselkumab?
We do not currently list a generic-labelled guselkumab product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Guselkumab: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/guselkumab
- MLA
- “Guselkumab: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/guselkumab.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for guselkumab on DailyMed (NIH) ↗.