The use of different concentrations of betaine as a reducing irritation agent in soaps monitored visually and non-invasively

Skin Res Technol. 2003 Feb;9(1):43-9. doi: 10.1034/j.1600-0846.2003.00362.x.


Background/aims: Products containing detergents can damage the skin and give rise to irritant contact dermatitis. Therefore, attempts have been made to find less irritating detergents as well as substances decreasing undesired side-effects of detergents, and a novel approach is offered by betaine. The aim of the study has been to determine the irritating properties of some liquid soaps for personal hygiene and to map the effect of different concentrations of betaine using electrical impedance, trans-epidermal water loss and visual inspection.

Methods: Twenty-eight healthy subjects were patch tested with different commercial soaps with and without betaine and sodium lauryl sulphate on both volar forearms for 24 h. A site with distilled water and an unoccluded area were used as references. Responses of the skin reactions were evaluated by visual inspection and by measuring trans-epidermal water loss and electrical impedance before application and 24 h after removal of the chambers.

Results/conclusions: Significant skin reactions were found for all soaps tested but the soaps containing betaine were the least irritating. However, the skin irritation did not decrease with increasing concentrations of betaine in the tested range. On the whole the differences between the products were not large. The non-invasive methods used were more sensitive than visual assessment for evaluation of invisible or barely visible skin responses.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Betaine / administration & dosage*
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Electric Impedance
  • Female
  • Humans
  • Irritants / antagonists & inhibitors*
  • Irritants / pharmacology*
  • Male
  • Osmolar Concentration
  • Skin / drug effects*
  • Skin / pathology
  • Skin / physiopathology
  • Skin Diseases / chemically induced
  • Skin Diseases / drug therapy*
  • Skin Diseases / physiopathology
  • Skin Tests
  • Soaps / chemistry*
  • Soaps / pharmacology
  • Sodium Dodecyl Sulfate / administration & dosage
  • Sodium Dodecyl Sulfate / adverse effects
  • Surface-Active Agents / administration & dosage
  • Surface-Active Agents / adverse effects
  • Water Loss, Insensible / drug effects


  • Irritants
  • Soaps
  • Surface-Active Agents
  • Sodium Dodecyl Sulfate
  • Betaine