What the label lists and what reports show
Febuxostat side effects
Febuxostat's FDA label: “Most Common Adverse Reactions In three randomized, controlled clinical studies (Studies 1, 2 and 3), which were 6 to 12 months in duration, the following adverse reactions were reported by the treating physician as related to study drug.” FAERS holds 16,668 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 diarrhoea (881 reports).
- Generic listed
- Boxed warning
Check it at the source: the febuxostat FDA label on DailyMed (effective December 24, 2025, Takeda Pharmaceuticals America, Inc.); 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 ULORIC?ULORIC may cause serious side effects, including: Heart problems. See " What is the most important information I should know about ULORIC? " . Gout Flares. Gout flares can happen when you start taking ULORIC. Your doctor may give you other medicines to help prevent your gout flares. Liver problems. Liver problems can happen in people who take ULORIC. Your doctor may do blood tests to check how well your liver is working before and during your treatment with ULORIC. Tell your doctor if you get any of the following signs or symptoms of liver problems: fatigue loss of appetite for several days or longer pain, aching, or tenderness on the right side of your stomach-area dark or "tea-colored" urine your skin or the white part of your eyes turns yellow (jaundice) Severe skin and allergic reactions. […]
Source: FDA drug label, Takeda Pharmaceuticals America, Inc., effective December 24, 2025 (SPL set 54de10ef-fe5f-4930-b91d-6bbb04c664bd), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost Common Adverse Reactions In three randomized, controlled clinical studies (Studies 1, 2 and 3), which were 6 to 12 months in duration, the following adverse reactions were reported by the treating physician as related to study drug.
Table 1: Adverse Reactions Occurring in ≥1% of Patients Treated with ULORIC and at Least 0.5% Greater than in Patients Receiving Placebo in Controlled Studies
| Adverse Reactions | (N=134) | 40 mg daily (N=757) | 80 mg daily (N=1279) | (N=1277) |
|---|---|---|---|---|
| Liver Function Abnormalities | 0.7% | 6.6% | 4.6% | 4.2% |
| Nausea | 0.7% | 1.1% | 1.3% | 0.8% |
| Arthralgia | 0% | 1.1% | 0.7% | 0.7% |
| Rash | 0.7% | 0.5% | 1.6% | 1.6% |
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 serious adverse reactions are described elsewhere in the prescribing information: Cardiovascular Death [see Warnings and Precautions (5.1) ] Hepatic Effects [see Warnings and Precautions (5.3) ] Serious Skin Reactions [see Warnings and Precautions (5.4) ] Adverse reactions in ≥ 1% of patients treated with ULORIC are liver function abnormalities, nausea, arthralgia, and rash. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Takeda Pharmaceuticals America, Inc. at 1-877-TAKEDA-7 (1-877-825-3327) 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. In Phase 2 and 3 clinical studies, a total of 2757 patients with hyperuricemia and gout were treated with ULORIC 40 mg or 80 mg daily. For ULORIC 40 mg, 559 patients were treated for ≥6 months. For ULORIC 80 mg, 1377 patients were treated for ≥6 months, 674 patients were treated for ≥1 year and 515 patients were treated for ≥2 years. In the CARES study, a total of 3098 patients were treated with ULORIC 40 mg or 80 mg daily; …
Source: FDA drug label, Takeda Pharmaceuticals America, Inc., effective December 24, 2025 (SPL set 54de10ef-fe5f-4930-b91d-6bbb04c664bd), via openFDA; the full label on DailyMed
What do FAERS reports show?
16,668 reports list febuxostat among the medicines taken, each a report of something that happened, not proof the medicine caused it; 2,179 are coded as a death and 7,176 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, 11 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?
- Febuxostat: 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