What the label lists and what reports show
Tofacitinib side effects
Tofacitinib's FDA label: “Most common adverse reactions are: • RA, PsA, and AS : Reported in ≥2% of adult patients treated with XELJANZ tablets monotherapy or in combination with DMARDs: upper respiratory tract infection (URI), nasopharyngitis, diarrhea, and headache.” FAERS holds 186,746 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is pain (26,333 reports).
- Generic listed
- Boxed warning
Check it at the source: the tofacitinib FDA label on DailyMed (effective July 13, 2026, U.S. Pharmaceuticals); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of XELJANZ/XELJANZ XR/XELJANZ oral solution?XELJANZ/XELJANZ XR/XELJANZ oral solution may cause serious side effects, including: • See " What is the most important information I should know about XELJANZ/XELJANZ XR/XELJANZ oral solution? " • Hepatitis B or C activation infection in people who carry the virus in their blood. If you are a carrier of the hepatitis B or C virus (viruses that affect the liver), the virus may become active while you use XELJANZ/XELJANZ XR/XELJANZ oral solution. Your healthcare provider may do blood tests before you start treatment with XELJANZ/XELJANZ XR/XELJANZ oral solution and while you are taking XELJANZ/XELJANZ XR/XELJANZ oral solution. […]
Source: FDA drug label, NDA203214 (Pf Prism Cv), as published by U.S. Pharmaceuticals, effective July 13, 2026 (SPL set 68e3d6b2-7838-4d2d-a417-09d919b43e13), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions are: • RA, PsA, and AS : Reported in ≥2% of adult patients treated with XELJANZ tablets monotherapy or in combination with DMARDs: upper respiratory tract infection (URI), nasopharyngitis, diarrhea, and headache.
Table 6: Common Adverse Reactions Reported in ≥4% of patients treated with either XELJANZ dosage and ≥1% greater in XELJANZ-treated patients than placebo-treated patients. in Adults with UC During the 52-Week…
| Preferred Term | Placebo N = 198 (%) | XELJANZ 5 mg Twice Daily N = 198 (%) | XELJANZ 10 mg Twice Daily N = 196 (%) |
|---|---|---|---|
| Nasopharyngitis | 6 | 10 | 14 |
| Elevated cholesterol levels Includes hypercholesterolemia, hyperlipidemia, blood… | 1 | 5 | 9 |
| Headache | 6 | 9 | 3 |
| Upper respiratory tract infection | 4 | 7 | 6 |
| Increased blood creatine phosphokinase | 2 | 3 | 7 |
| Rash | 4 | 3 | 6 |
| Diarrhea | 3 | 2 | 5 |
| Herpes zoster | 1 | 1 | 5 |
| Gastroenteritis | 3 | 3 | 4 |
| Anemia | 2 | 4 | 2 |
| Nausea | 3 | 1 | 4 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are described elsewhere in the labeling: • Serious Infections [see Warnings and Precautions (5.1) ] • Increased Risk of Mortality [see Warnings and Precautions (5.2) ] • Malignancy and Lymphoproliferative Disorders [see Warnings and Precautions (5.3) ] • Major Adverse Cardiovascular Events [see Warnings and Precautions (5.4) ] • Thrombosis [see Warnings and Precautions (5.5) ] • Gastrointestinal Perforations [see Warnings and Precautions (5.6) ] • Hypersensitivity Reactions [see Warnings and Precautions (5.7) ] • Hypoglycemia in Patients with Diabetes [see Warnings and Precautions (5.8) ] • Laboratory Abnormalities [see Warnings and Precautions (5.9) ] Most common adverse reactions are: • RA, PsA, and AS : Reported in ≥2% of adult patients treated with XELJANZ tablets monotherapy or in combination with DMARDs: upper respiratory tract infection (URI), nasopharyngitis, diarrhea, and headache. ( 6.1 ) • PcJIA : Consistent with common adverse reactions reported in adult patients with RA. ( 6.1 ) • UC : Reported in ≥ 5% of adult patients treated with either XELJANZ tablets and ≥1% greater than reported in patients treated with placebo: nasopharyngitis, elevated cholesterol levels, headache, URI, increased blood creatine phosphokinase, rash, diarrhea, and herpes zoster.
Source: FDA drug label, NDA203214 (Pf Prism Cv), as published by U.S. Pharmaceuticals, effective July 13, 2026 (SPL set 68e3d6b2-7838-4d2d-a417-09d919b43e13), via openFDA; the full label on DailyMed
What do FAERS reports show?
186,746 reports list tofacitinib among the medicines taken, each a report of something that happened, not proof the medicine caused it; 9,652 are coded as a death and 26,629 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 20 reactions below, 9 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Tofacitinib: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions