Effect of topical clay application on the synthesis of collagen in skin: an experimental study

Clin Exp Dermatol. 2012 Mar;37(2):164-8. doi: 10.1111/j.1365-2230.2011.04216.x.


Background: Clay is often used in cosmetic treatments, although little is known about its action.

Aim: To evaluate the effect of topical clay application on the histoarchitecture of collagen fibres in rat skin.

Methods: Animals received a daily application of clay and retinoic acid (RA) 0.025% to the dorsal skin over 7 and 14 days, under vaporization at 37 °C for 40 min. Control skin was not vaporized. Samples from each region were excised, and stained with picrosirius red for collagen evaluation.

Results: Seven days after clay treatment, an increase in the number of collagen fibres was observed in treated skin compared with control skin (51.74 ± 1.28 vs. 43.39 ± 1.79%, respectively, P < 0.01), whereas RA did not alter the collagen level (45.66 ± 1.10%). Clay application over 14 days did not induce a further increase in skin collagen, whereas treatment with RA did (58.07 ± 1.59%; P = 0.001 vs. control).

Conclusion: Clay application promotes an increase in the number of collagen fibres, which may account for its beneficial effects.

MeSH terms

  • Administration, Topical
  • Aluminum Silicates / administration & dosage
  • Aluminum Silicates / pharmacology*
  • Animals
  • Clay
  • Collagen / drug effects*
  • Cosmetics / administration & dosage
  • Cosmetics / pharmacology*
  • Keratolytic Agents / pharmacology
  • Male
  • Rats
  • Rats, Wistar
  • Skin / drug effects*
  • Tretinoin / pharmacology


  • Aluminum Silicates
  • Cosmetics
  • Keratolytic Agents
  • Tretinoin
  • Collagen
  • Clay