Comprehensive medication guide to Fluorouracil including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$30 copay for topical generic (Tier 1–2 on most formularies); IV fluorouracil for cancer treatment is covered under Medicare Part B at 80% of the approved amount after the deductible, or Part A during hospital stays; prior authorization may apply for brand-name topical formulations.
Estimated Cash Pricing
$30–$365 retail depending on formulation; generic fluorouracil 5% cream (40g) runs $200–$365 retail but as low as $29–$34 with GoodRx or SingleCare coupons; IV injection (four 10 mL vials) costs $65–$145 without insurance.
Medfinder Findability Score
40/100
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Fluorouracil — commonly abbreviated as 5-FU or 5-fluorouracil — is a pyrimidine analog antimetabolite chemotherapy drug that has been in clinical use since its initial FDA approval in 1962. It is one of the most widely prescribed chemotherapy agents in the world and remains a cornerstone of treatment for multiple solid tumor types.
Fluorouracil is available in two distinct formulations: an intravenous (IV) injection (50 mg/mL, brand name Adrucil) used for systemic cancer treatment, and topical creams at various strengths (0.5% Carac, 4% Tolak, 5% Efudex and generics) used to treat precancerous and cancerous skin lesions.
The IV form is FDA-approved for colorectal adenocarcinoma, gastric adenocarcinoma, pancreatic adenocarcinoma, and breast adenocarcinoma. The topical form is approved for actinic keratoses and superficial basal cell carcinomas. Off-label IV uses include anal carcinoma, esophageal cancer, cervical cancer, biliary tract cancer, and head and neck cancers.
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Fluorouracil works by mimicking uracil, a natural building block of RNA and DNA. Because cancer cells are rapidly dividing, they take up fluorouracil and attempt to use it in their replication machinery — but it doesn't work properly. Inside cells, fluorouracil is converted to two active metabolites: FdUMP and FUTP.
FdUMP irreversibly binds to thymidylate synthase — an enzyme essential for DNA synthesis — effectively jamming it. Without functional thymidylate synthase, cells cannot make the thymidine they need to copy DNA, halting cell division. Leucovorin (folinic acid) is commonly given alongside fluorouracil to enhance this binding and increase efficacy.
FUTP, the other active metabolite, gets incorporated into RNA molecules in place of normal uridine, corrupting the cellular messaging system. This disrupts protein synthesis and further impairs cancer cell function. Fluorouracil is S-phase specific, meaning it is most effective when cells are actively copying their DNA.
50 mg/mL — IV injection
Adrucil; available in 10 mL, 20 mL, 50 mL, and 100 mL vials for chemotherapy administration
0.5% — topical cream
Carac — for actinic keratosis; apply once daily for up to 4 weeks
4% — topical cream
Tolak — for actinic keratosis; apply once daily for 4 weeks
5% — topical cream/solution
Efudex, generic — for actinic keratosis and superficial basal cell carcinoma; apply twice daily for 2-6 weeks
Fluorouracil injection has been on the ASHP Drug Shortage Database since January 2023 and remains in active shortage as of early 2026. The shortage is driven by manufacturing delays at multiple suppliers including Accord, Alembic, Eugia US, and Xiromed. Fresenius Kabi and Sagent continue to maintain available supply, but uneven distribution means regional and pharmacy-level shortages persist.
Topical fluorouracil creams face intermittent supply issues as well, particularly Carac 0.5%. Generic 5% cream is generally more available than branded formulations, but availability varies by region and pharmacy. Availability at any given pharmacy can change week to week.
If you're having difficulty finding fluorouracil at your regular pharmacy, medfinder can call pharmacies in your area to find which ones have it in stock and text you the results — saving you hours of phone calls.
Fluorouracil is not a controlled substance and has no special DEA prescribing registration requirements. Any licensed prescriber with appropriate scope of practice can prescribe it. In practice, prescribers vary significantly by indication:
Medical Oncologists: Primary prescribers of IV fluorouracil for colorectal, gastric, pancreatic, and breast cancers.
Hematologist-Oncologists: Manage both solid tumors and blood cancers; often prescribe in community oncology settings.
Radiation Oncologists: Co-prescribe fluorouracil when used as a radiosensitizer for anal, rectal, or head and neck cancers.
Dermatologists: Primary prescribers of topical fluorouracil for actinic keratosis and superficial basal cell carcinoma.
Primary Care Physicians (MD/DO): May prescribe topical fluorouracil for actinic keratosis in straightforward presentations.
Nurse Practitioners (NP) and Physician Assistants (PA): NPs and PAs in oncology and dermatology practices regularly prescribe fluorouracil within their scope of practice.
Telehealth prescribing is available for topical fluorouracil through dermatology telehealth platforms. IV fluorouracil requires in-person oncology evaluation and must be administered in a clinical setting.
No. Fluorouracil is not a DEA-scheduled controlled substance. It is a prescription-only medication, but it has no special scheduling restrictions under the Controlled Substances Act. Any licensed prescriber — physician (MD/DO), nurse practitioner (NP), or physician assistant (PA) — can prescribe fluorouracil without special DEA registration beyond standard prescribing authority.
There are no refill quantity limits or early refill restrictions tied to scheduling. However, some insurance formularies may have quantity limits or prior authorization requirements for certain fluorouracil formulations, particularly brand-name topical products. Patients should check their specific plan's formulary for coverage details.
Common side effects of IV fluorouracil (chemotherapy) include:
Stomatitis (mouth sores and throat inflammation)
Nausea and vomiting
Diarrhea
Myelosuppression (low white blood cells, red blood cells, and platelets)
Hand-foot syndrome (redness, peeling, soreness on palms and soles)
Hair thinning and fatigue
Serious side effects requiring immediate medical attention:
Cardiotoxicity: chest pain, angina, arrhythmia, or signs of heart failure
Acute cerebellar syndrome: balance loss, ataxia, nystagmus, confusion
Fever above 100.4°F — may signal neutropenic fever (medical emergency)
Life-threatening toxicity in patients with DPD deficiency (DPYD gene variants)
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Capecitabine (Xeloda)
Oral prodrug of 5-FU converted in the body; equivalent to infusional 5-FU for many cancer types; avoids IV administration; same DPD deficiency risk.
Oxaliplatin (Eloxatin)
Platinum-based chemotherapy used in combination with 5-FU in FOLFOX; in shortage situations, FOLFOX can be converted to CAPOX (capecitabine + oxaliplatin).
Tirbanibulin (Klisyri)
Topical treatment for actinic keratosis on face/scalp; only 5-day treatment course; FDA-approved 2020; different mechanism from fluorouracil.
Imiquimod (Zyclara, Aldara)
Immune response modifier cream for actinic keratosis and superficial BCC; stimulates local immune response; FDA-approved alternative to topical fluorouracil.
Prefer Fluorouracil? We can find it.
Warfarin (Coumadin)
majorFluorouracil significantly increases warfarin's anticoagulant effect; INR must be monitored frequently during and after fluorouracil cycles.
Brivudine / Sorivudine
majorPotent DPD inhibitors; concurrent use can cause life-threatening fluorouracil accumulation. Not currently approved in the US but sold in Europe.
Metronidazole (Flagyl)
majorInhibits fluorouracil metabolism, increasing blood levels and toxicity risk.
Leucovorin (folinic acid)
moderateTherapeutically enhances fluorouracil's thymidylate synthase inhibition; increases efficacy and toxicity.
Cimetidine (Tagamet)
moderateH2 blocker that may increase fluorouracil blood levels; consider alternatives like famotidine.
Allopurinol
moderateMay reduce fluorouracil effectiveness by interfering with its activation pathway.
Fluorouracil is one of medicine's most important and most enduring chemotherapy agents — over 60 years of clinical use and it remains irreplaceable in the treatment of colorectal, gastric, pancreatic, and breast cancers, as well as actinic keratosis and superficial basal cell carcinoma in dermatology. Its ongoing supply shortage is a frustrating reality driven by thin manufacturing margins and concentrated supply chains.
Key considerations for patients in 2026: ask your oncologist about DPYD genetic testing before starting treatment (updated FDA guidance, February 2026), start searching for your medication at least 5-7 days before it's needed, and have a conversation with your provider about contingency plans if supply becomes unavailable.
If you're having trouble finding fluorouracil at a pharmacy near you, medfinder will call pharmacies in your area to find which ones can fill your prescription and text you the results. No hold music, no repeated phone calls — just results.
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Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
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