A potent lipoxygenase inhibitor that interferes with arachidonic acid metabolism. The compound also inhibits formyltetrahydrofolate synthetase, carboxylesterase, and cyclooxygenase to a lesser extent. It also serves as an antioxidant in fats and oils. [PubChem]



Used for the treatment of actinic keratoses (precancerous skin growths that can become malignant if left untreated).


Masoprocol is a novel antineoplastic agent. It is not known exactly how masoprocol works. Laboratory experiments have shown that masoprocol prevents cells similar to the ones found in actinic keratoses from multiplying. Masoprocol was withdrawn from the U.S. market in June 1996.

Mechanism of action

Although the exact mechanism of action is not known, studies have shown that masoprocol is a potent 5-lipoxygenase inhibitor and has antiproliferative activity against keratinocytes in tissue culture, but the relationship between this activity and its effectiveness in actinic keratoses is unknown. M... Read more


Less than 1%-2% is absorbed through the skin over a 4-day period following application.

Protein binding

Information currently not available.

Volume of distribution

Information currently not available.


Information currently not available.

Half life

Information currently not available.

Route of elimination

Information currently not available.


Symptoms of overdose or allergic reaction include bluish coloration of skin, dizziness, severe, or feeling faint, wheezing or trouble in breathing.

Adverse Effects


Information currently not available.

Food Interactions

    Information currently not available.


Type in a drug name to check for interaction with Masoprocol
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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
Darbepoetin alfa
The risk or severity of Thrombosis can be increased when Darbepoetin alfa is combined with Masoprocol.
The risk or severity of Thrombosis can be increased when Erythropoietin is combined with Masoprocol.
Methoxy polyethylene glycol-epoetin beta
The risk or severity of Thrombosis can be increased when Methoxy polyethylene glycol-epoetin beta is combined with Masoprocol.
The risk or severity of Thrombosis can be increased when Peginesatide is combined with Masoprocol.