Tremfya 100mg Injection

Tremfya is an FDA-approved biologic medication that blocks interleukin-23 (IL-23), a protein that drives inflammation in psoriasis, psoriatic arthritis, and inflammatory bowel disease. Manufactured by Janssen (Johnson & Johnson), it is delivered as a 100mg subcutaneous injection via prefilled syringe, One-Press injector, or Tremfya Pen, and is intended for use under physician supervision.

Before Starting Tremfya

Patients should be evaluated for tuberculosis and brought up to date on age-appropriate vaccinations before starting Tremfya, since it affects immune function.

• TB screening is required before treatment initiation
• Liver enzymes and bilirubin should be evaluated at baseline, particularly for Crohn's/UC patients
• Inform your doctor of any current infections, recent travel, or household TB exposure
• Effective contraception is recommended during treatment, as Tremfya has not been studied in pregnancy

References

1. U.S. FDA — TREMFYA Prescribing Information
2. Drugs.com — Tremfya: Uses, Dosage, Side Effects & Warnings
3. American College of Rheumatology — Guselkumab (Tremfya) Patient Information

Medically reviewed. Last updated: [20/06/2026]. This content is for informational purposes and does not replace consultation with a licensed physician.

How it works

Tremfya works by selectively blocking IL-23, a signaling protein that triggers the inflammatory cascade behind psoriasis and related autoimmune conditions. By neutralizing IL-23 specifically, it interrupts inflammation upstream, which is why it's classified as an interleukin inhibitor rather than a broader immunosuppressant.

Tremfya is indicated for adults and children 6 years and older (weighing at least 40 kg) with moderate-to-severe plaque psoriasis, active psoriatic arthritis, Crohn's disease, and ulcerative colitis.

• Plaque psoriasis: for patients who are candidates for systemic therapy or phototherapy
• Psoriatic arthritis: can be used alone or combined with a conventional DMARD such as methotrexate
• Crohn's disease: for moderately to severely active disease, typically starting with an induction phase
• Ulcerative colitis: for moderately to severely active disease, following the same induction-then-maintenance approach

The standard maintenance dose is 100mg by subcutaneous injection at Week 0, Week 4, and every 8 weeks thereafter.

• Plaque psoriasis / psoriatic arthritis: 100mg subcutaneous at Weeks 0, 4, then every 8 weeks
• Crohn's disease / ulcerative colitis (induction): 200mg IV infusion at Weeks 0, 4, and 8, or a 400mg subcutaneous induction option
• Maintenance (Crohn's/UC): 100mg subcutaneous every 8 weeks, or 200mg subcutaneous every 4 weeks
• Injection sites: front of thighs, lower abdomen (avoiding 2 inches around the navel), or back of the upper arm (administered by a healthcare professional or trained caregiver)
• Adults may self-inject after proper training; pediatric self-administration is not recommended

The most common side effects of Tremfya include upper respiratory infections, headache, injection site reactions, joint pain, and diarrhea.

• Upper respiratory infections
• Headache
• Injection site reactions (pain, redness, swelling)
• Arthralgia (joint pain)
• Diarrhea and gastroenteritis
• Tinea (fungal) infections and herpes simplex infections

Because Tremfya affects immune response, patients should contact their care team promptly if signs of infection, fever, or allergic reaction develop.