Efficacy of a new tonic containing urea, lactate, polidocanol, and glycyrrhiza inflata root extract in the treatment of a dry, itchy, and subclinically inflamed scalp

Skin Pharmacol Physiol. 2013;26(2):108-18. doi: 10.1159/000348473. Epub 2013 Mar 21.


Background/aims: Dry, itchy and inflamed scalp conditions are common and often associated with diseases such as atopic dermatitis or psoriasis. To improve these symptoms, we investigated the efficacy of a new tonic containing the active ingredients urea, lactate, polidocanol, and Glycyrrhiza inflata root extract, containing licochalcone A.

Study design/methods: 30 subjects with dry and itchy scalp conditions underwent a randomized half-head study for 4 weeks, applying the leave-on tonic three times a week on one side of the scalp. Tonic effects on skin hydration, itching, lipids, microinflammation, and substantivity of tonic compounds were determined using corneometry, middle-infrared spectroscopy, direct analysis in real-time mass spectrometry, and enzyme-linked immunosorbent assay. Volunteers performed a self-assessment; changes in scalp condition were documented by in vivo microscopy.

Results: After tonic treatment, scalp moisture was significantly increased, whereas scalp itching and tautness were significantly reduced. Results also demonstrated a high substantivity of urea and lactate on the scalp, an increase in triglyceride, and a decrease in free fatty acid levels. The amount of total lipids was unchanged. Analyses of scalp wash-ups verified a significant reduction in important pro-inflammatory markers.

Conclusion: Due to the actives urea, lactate, polidocanol, and the anti-inflammatory licochalcone A, the new scalp tonic exhibited excellent performance in alleviating scalp dryness, itching, microinflammation, and in normalizing disturbances of scalp lipids.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Chalcones / administration & dosage*
  • Cytokines / metabolism
  • Glycyrrhiza
  • Humans
  • Lactic Acid / administration & dosage*
  • Lipid Metabolism
  • Plant Extracts / administration & dosage
  • Plant Roots
  • Polidocanol
  • Polyethylene Glycols / administration & dosage*
  • Pruritus / drug therapy*
  • Scalp / metabolism
  • Scalp Dermatoses / drug therapy*
  • Urea / administration & dosage*


  • Chalcones
  • Cytokines
  • Plant Extracts
  • Polidocanol
  • Lactic Acid
  • Polyethylene Glycols
  • Urea
  • licochalcone A