A controlled trial of a dissolving oral patch concerning glycyrrhiza (licorice) herbal extract for the treatment of aphthous ulcers

Gen Dent. Mar-Apr 2008;56(2):206-10; quiz 211-2, 224.


Recurrent aphthous ulcers (RAU) are a common and painful condition. This article describes a randomized, double-blind clinical trial of an over-the-counter medicated intraoral adhesive patch for treatment of RAU. Subjects were randomly assigned to either an active drug (patch with extract of glycyrrhiza root) or placebo patch treatment group (both n=23) at onset of a lesion. Lesion size and pain report (unstimulated and stimulated) were assessed at intervals. A no-treatment group (n=23) also was recruited and assessed similarly. By the eighth day, the ulcer size for the active treatment group was significantly lower (p < 0.05), while the By the fourth day, the active treatment group lesions in the no-treatment group increased 13% from baseline.reported significantly less pre-stimulus pain (p < 0.01); at this point, 81% of this group reported no pre-stimulus pain, comp ared with 63% of the placebo patch group and 40% of the no-treatment group

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Adolescent
  • Analysis of Variance
  • Bandages, Hydrocolloid
  • Double-Blind Method
  • Drug Delivery Systems
  • Glycyrrhiza*
  • Humans
  • Nonprescription Drugs / therapeutic use
  • Pain / complications
  • Pain / drug therapy*
  • Phytotherapy
  • Plant Extracts / therapeutic use*
  • Stomatitis, Aphthous / complications
  • Stomatitis, Aphthous / drug therapy*


  • Nonprescription Drugs
  • Plant Extracts