The content provided here is for informational purposes only and should not be considered a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of your physician or another qualified healthcare provider with any questions you may have regarding a medical condition.

1. https://reference.medscape.com/drug/tremfya-guselkumab-1000164

2. https://go.drugbank.com/drugs/DB11834

3. https://www.ema.europa.eu/en/documents/product-information/tremfya-epar-product-information_en.pdf 

4. https://www.jnj.com/media-center/press-releases/tremfya-guselkumab-receives-u-s-fda-approval-for-adults-with-moderately-to-severely-active-ulcerative-colitis-strengthening-johnson-johnsons-leadership-in-inflammatory-bowel-disease

Once your doctor starts you on this treatment, follow the dosage and timing strictly—even if your symptoms improve. Store the injection pens in the refrigerator and let them come to room temperature before use. Never inject into inflamed or bruised skin. Keep a symptom diary to track how your skin and joints respond. Also, maintain a healthy diet and lifestyle to support your immune system naturally. Remember, this is a long-term treatment and results may take several weeks to become noticeable.

Before starting this medicine, you should be tested for tuberculosis. Inform your doctor if you have a history of chronic infections, liver issues, or immune system disorders. Tell your healthcare provider about all the medicines and supplements you take. It’s also important to avoid alcohol and smoking, which can worsen inflammation and reduce the drug's effectiveness. If you’re pregnant or breastfeeding, discuss the risks and benefits before starting therapy.

• Do not use if you have a severe allergic reaction to any ingredient in this medication.

• Avoid use in patients with active tuberculosis or other severe infections.

• Live vaccines should not be given during treatment.

• May interact with other immunosuppressants; consult your doctor before combining medications.

• Risk of lower immune function, which may make it harder to fight infections.

Common Side Effects:

• Upper respiratory infections (cold, sore throat)

• Headache

• Diarrhea

• Joint pain

• Redness or pain at the injection site

Serious Side Effects:

• Serious allergic reactions (rash, swelling, difficulty breathing)

• Increased risk of infections such as tuberculosis (TB)

• Liver enzyme abnormalities

• Reactivation of latent infections (like hepatitis B)

Contact your doctor immediately if you experience persistent fever, chills, cough, or shortness of breath.

Guselkumab is given as an injection under the skin (subcutaneous injection). It is usually administered once every 8 weeks after the initial two starter doses. The medicine comes in a 100 mg/mL prefilled syringe or autoinjector, which can be used at home after proper training from a healthcare provider. Your doctor will decide the best dosing schedule based on your condition and response to treatment.

This medicine works by blocking a specific protein in the immune system called interleukin-23 (IL-23). In people with psoriasis and psoriatic arthritis, IL-23 sends the wrong signals, triggering the body to attack its own skin and joints, leading to red, scaly patches or painful joint swelling. By stopping these signals, the drug helps reduce skin inflammation and joint damage. Over time, this helps in clearing up the skin and improving mobility and quality of life for those suffering from these autoimmune conditions.

Guselkumab is FDA-approved for the treatment of:

• Moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy

• Active psoriatic arthritis in adults, either alone or in combination with other arthritis medicines

Guselkumab is a prescription medicine developed to manage certain long-term inflammatory diseases that affect the skin and joints. It belongs to a class of medications known as biologics and works by calming down an overactive immune system, which is often the root cause of these conditions. The U.S. Food and Drug Administration (FDA) first approved it in July 2017, following successful clinical trials that showed significant improvements in people with moderate-to-severe plaque psoriasis. Later studies confirmed its role in helping patients with joint-related conditions, too. Its long-lasting effect and convenient dosing schedule have made it a preferred choice among doctors for managing chronic symptoms without daily medication.