Fluorouracil: Side Effects, Uses & Monitoring
Fluorouracil is recommended for the topical treatment of multiple actinic or solar keratoses.
- Data source
- FDA labeling via NIH DailyMed (label 2c631ce7…)
- Label version
- current
- Last reviewed
- 2026
Reported adverse reactions
Reactions listed in current FDA labeling, with the highest frequency reported across summarized placebo-controlled trials.
No structured frequency data available in current labeling. Consult the official label.
Labeled uses (from FDA prescribing information)
Fluorouracil is recommended for the topical treatment of multiple actinic or solar keratoses. In the 5% strength, it is also useful in the treatment of superficial basal cell carcinomas when conventional methods are impractical, such as with multiple lesions or difficult treatment sites. Safety and efficacy in other indications have not been established. The diagnosis should be established prior to treatment, since this method has not been proven effective in other types of basal cell carcinomas. With isolated, easily accessible basal cell carcinomas, surgery is preferred since success with such lesions is almost 100%. The success rate with fluorouracil solution and a different dosage form is approximately 93%, based on 113 lesions in 54 patients. Twenty-five lesions treated with the solution produced 1 failure and 88 lesions treated with a different dosage form produced 7 failures.
Frequently Asked Questions
What is Fluorouracil used for?
FDA labeling lists the approved uses shown above under "Labeled uses." This summary is informational; only a qualified prescriber can determine whether a medication is appropriate for you.
What are the most commonly reported side effects of Fluorouracil?
Current labeling for this ingredient does not include a structured frequency table that we can reproduce. Review the official label linked below.
Does Fluorouracil require lab monitoring?
Monitoring needs vary. Ask your healthcare provider whether any lab tests apply while taking Fluorouracil.
Where does this information come from?
All clinical facts on this page were extracted from the current FDA-registered product labeling for this ingredient, published by manufacturers through NIH DailyMed. See the source link below.
Medical disclaimer: Educational content extracted from public FDA labeling. Not medical advice. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.