What is imiquimod, and how does it work (mechanism of action)?

Imiquimod is a topical medication that activates the immune system and is used for treating (not curing) genital warts. Although the exact mechanism of action imiquimod is not known, imiquimod is presumed to work by activating immune cells and chemicals that affect the immune the system. The FDA approved brand name imiquimod (Aldara) in February 1997.

What brand names are available for imiquimod?

Aldara, Zyclara

Is imiquimod available as a generic drug?


Do I need a prescription for imiquimod?


What are the side effects of imiquimod?

Side effects of imiquimod are:

What is the dosage for imiquimod?

Adults and children of ages 12 and older:

Actinic keratosis: Apply Aldara to specific treatment area two times a week for 16 weeks.  

Superficial basal cell carcinoma: Apply to specific treatment area five times a week for 6 weeks.

External genital warts: Apply Aldara three times a week until clearance of warts or for a maximum of 16 weeks.

Safe and effective use of imiquimod is not established for children under the age of 12.

Which drugs or supplements interact with imiquimod?

No drug-drug interactions have been conducted and established with imiquimod.


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Is imiquimod safe to take if I'm pregnant or breastfeeding?

There are no adequate studies done on imiquimod to determine safe and effective use in pregnant women.

It is not known whether imiquimod enters breast milk. It is best to be cautious before using it in nursing mothers.

What else should I know about imiquimod?

What preparations of imiquimod-topical are available?

Cream: 2.5%, 3.75%, and 5%

How should I keep imiquimod-topical stored?

Store imiquimod cream between temperatures of 4 C to 25 C (39 F - 77 F).


Imiquimod (Aldara, Zyclara) is a topical cream used in the treatment of genital warts. The medication works by stimulating the immune system cells and chemicals to attack the affected area. The medicine may also be prescribed to fight different types of skin cancer. Side effects, drug interactions, and patient safety information should be reviewed prior to taking this medication.

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Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine


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