Fluorouracil cream

Key points about fluorouracil cream

  • Fluorouracil cream is a treatment that selectively destroys sun-damaged cells in the skin whilst keeping the normal healthy skin cells.
  • It belongs to a group of medicines known as anti-cancer medicines (also called antineoplastic or cytotoxic medicines).
  • Fluorouracil cream is also called Efudix or 5-FU cream.
  • Find out about how to apply it safely.
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  • Fluorouracil cream is used to treat sun-damaged skin, pre-cancerous skin lesions such as actinic keratoses (also called solar keratoses), squamous cell carcinoma and for the treatment of superficial basal cell carcinoma.
  • It works by blocking the growth of abnormal cells that cause these skin conditions.     
  • Fluorouracil cream is also sometimes used to treat other skin conditions, eg, viral warts.

  • In Aotearoa New Zealand, fluorouracil cream is available as a 5% cream.
  • How often and for how long you should use fluorouracil cream will depend on your skin condition and which part of your skin is affected.
  • Usually, the cream is used once or twice a day.
  • Treatment is usually needed for 3 to 4 weeks.
  • Always use your fluorouracil cream exactly as your doctor has told you.
  • The pharmacy label on your medicine will tell you how much fluorouracil cream to use, how often to use it, and any special instructions.

  • Wash the affected area with plain water.
  • Use your fingertip or a cotton bud to apply a thin layer of cream to the affected area only.
  • Wash your hands thoroughly after applying fluorouracil cream, even if you have used gloves.
  • Timing
    • If you are asked by your doctor to apply fluorouracil cream once a day, you should apply it in the morning.
    • If twice-a-day application is recommended, then apply it in the morning and late afternoon – don't apply it just before bed because it might get on your sheets.
  • Missed dose: If you forget to apply a dose, wait until the next dose is due and continue as usual.
  • Large areas: If you have widespread sun-damage divide the affected area into smaller areas and complete treatment in one area before moving on to the next. This will help make the treatment reaction more tolerable. Your doctor will provide further advice about this.
  • Applying other topical products: You can apply moisturisers and/or make-up as part of your usual skin care routine, 20 minutes after applying fluorouracil cream.

  • Don't apply fluorouracil cream on broken or sunburnt skin.
  • Take care not to get the cream in your eyes and nostrils or on your lips.
  • Avoid spending lots of time in the sun, or swimming – this might cause a skin rash. Also be sunsafe by wearing clothing and/or a hat to cover the treatment site, and use sunscreens.
  • Only cover fluorouracil cream with a plaster if advised to do so by your doctor, otherwise leave the treated area uncovered. Covering the treatment area with a plaster is likely to induce a more severe skin reaction. When treating superficial basal cell carcinomas, however, covering the area with a plaster is often recommended.​
  • Expect your appearance to look worse and to feel uncomfortable while treatment is in progress. Although the skin seems to be worse, it's a sign that the medication is working.
  • Store your cream out of reach by children and pets. Fluorouracil is extremely toxic to cats and dogs who may accidentally chew the container or lick your skin where you have applied the cream.

  • Sometimes it can take several weeks after treatment has stopped before you see any improvement in your condition.
  • It can take up to 6 weeks for healthy new skin to replace the damaged skin destroyed by the fluorouracil cream.
  • Plain white petrolatum (petroleum jelly) can be applied to the raw and crusted areas until they have healed.
  • The treated areas may continue to be more sensitive for several months.
  • If the skin lesion is still there 3 months after treatment, go back to see your healthcare provider.

  • Are you pregnant or planning to become pregnant?
  • Are you breastfeeding?
  • Do you have any inflammatory skin conditions?
  • Do you work outside for long periods of time during the day?

If you have answered yes to any of these questions, it’s important that you tell your doctor or pharmacist before you use fluorouracil cream. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Taking other medicines

Fluorouracil cream can interact with some medications, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting fluorouracil cream and before starting any new products.

Like all medicines, fluorouracil cream can cause unwanted side effects, although not everyone gets them. Often these side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Skin redness
  • Skin peeling
  • Itchiness
  • Burning, stinging or ulceration at the site of application
  • Irritation
  • Inflammation
  • Increased sensitivity of the skin to the sun
  • These are quite common when you first start using fluorouracil cream.
  • Usually the area will get red after 3–5 days and may peel after 10–14 days.
  • If this becomes very uncomfortable or very sore, stop the cream and tell your doctor. 
  • Changes in skin colour at the site of application
  • Sleeping problems
  • Temporary hair loss
  • Abnormal taste in the mouth 
  • Scarring


  • Tell your doctor if these bother you.  
  • Allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing such as chest tightness, or wheezing
  • Tell your doctor immediately or ring Healthline 0800 611 116.
For more information on side effects, see the Medsafe consumer information leaflet Efudix.(external link)

Did you know that you can report a medicine side effect to the Centre for Adverse Reactions Monitoring (CARM)? Report a side effect to a product.(external link)

The following links provide further information on fluorouracil cream:

Efudix (external link) Medsafe Consumer Information Sheet, NZ
Fluorouracil cream (Efudix) Patient Information Guide(external link) SafeRx, Waitematā DHB, NZ
5-Fluorouracil cream(external link) DermNet, NZ

References

  1. Fluorouracil(external link) NZ Formulary
  2. 5-Fluorouracil cream(external link) British Association of Dermatologists, UK

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Maya Patel, MPharm PGDipClinPharm, Auckland

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