Does Tremfya List Weight Gain as a Side Effect?
Tremfya (guselkumab), an IL-23 inhibitor for psoriasis, psoriatic arthritis, and Crohn's disease, does not list weight gain among its common or serious side effects in official prescribing information. Clinical trials reported upper respiratory infections, headache, injection site reactions, arthralgia, diarrhea, gastroenteritis, tinea infections, and herpes infections as frequent issues, but weight changes were not highlighted.[1]
What Do Real-World Patient Reports Say?
Some patients report modest weight gain on forums like Drugs.com and Reddit, often 5-15 pounds over months, potentially linked to reduced inflammation improving appetite or lifestyle changes from symptom relief. These are anecdotal, not proven causal. In post-marketing data, weight gain appears rare and unconfirmed as directly related.[2][3]
How Does Tremfya Compare to Other Biologics on Weight?
Unlike some TNF inhibitors (e.g., Humira or Enbrel), which occasionally correlate with weight gain in studies (up to 5-10% of users), Tremfya's IL-23 mechanism shows neutral or minimal impact in head-to-head trials. Stelara (ustekinumab), another IL-12/23 inhibitor, has similar low reports of weight changes.[4]
Why Might Someone Experience Weight Gain Anyway?
Indirect factors include:
- Better disease control leading to higher calorie intake or less pain-limited activity.
- Co-prescribed steroids or comorbidities like hypothyroidism.
- Rarely, hypersensitivity reactions causing fluid retention.
Monitor BMI and consult a doctor if unexplained gain exceeds 5% body weight.[1]
When Should You Talk to Your Doctor?
Report persistent weight gain alongside symptoms like swelling or fatigue. No black-box warnings apply, but FDA monitors via FAERS database show isolated cases without establishing causation.[5]
[1]: Tremfya Prescribing Information (Janssen)
[2]: Drugs.com Tremfya Reviews
[3]: FDA FAERS Database Search
[4]: JAAD Study on Biologics and Weight (2020)
[5]: FDA Adverse Event Reporting System