SALICYLIC ACID

Salicylic acid is a chemical exfoliant, that is to say, it eliminates excess sebum and excess dead cells on the surface of the skin by dissolving the lipid cement that binds the cells together. This allows you to find more radiant skin, tighter pores and to avoid imperfections. Salicylic acid works from 0.5% and it is allowed in Europe at a percentage of 2%.


Salicylic acid is part of the family of hydroxy acids. This family includes alpha hydroxylated acids which are abbreviated as AHA , such as glycolic acid or lactic acid and beta hydroxylated acid, BHA , which is salicylic acid. The prefix alpha or beta only denotes the position of the hydroxyl group –OH with respect to the carboxyl group –COOH in the molecule.

Salicylic acid also differs from AHAs in several other ways:

  • Unlike AHAs which are soluble in water, BHA is lipophilic, that is to say soluble in oil, which gives it a better ability to penetrate directly into the pores of the skin to decongest them. It is the perfect asset to avoid imperfections.
  • Being from the same family as aspirin (acetylsalicylic acid), salicylic acid also has anti-inflammatory and antibacterial properties which makes it ideal for acne-prone skin.
  • Unlike AHAs which need an acid pH around 3.5 to function, salicylic acid is able to function at physiological pH, that is to say at the pH of the skin (between 4.5 and 5.5) which decreases potential irritation during use.
  • Unlike AHAs which are photosensitive, that is to say which make the skin more sensitive to the sun and this from the first use and for several days. Salicylic acid is not and would even be photoprotective.

In summary :
Salicylic acid is an excellent exfoliating agent with anti-inflammatory and antibacterial properties, perfect for oily skin and/or skin with inflammation, enlarged pores, blackheads or whiteheads.


Sources:

  • Final Opinion on salicylic acid, SCCS, December 2018
  • Exfoliation for sensitive skin with neutralized salicylic acid? International journal of cosmetic science, Volume 31, Issue 3, Pages 243-244, June 2009
  • Stratum Corneum Exfoliation Effect with Hydroxy Acid according pH, Journal of the Society of Cosmetic Scientists of Korea, Volume 42 Issue 4, Pages 413-420, 2016
  • Applications of hydroxy acids: classification, mechanisms, and photoactivity, Clinical, Cosmetic and Investigational Dermatology, 2010
  • The Effects of Topically Applied Glycolic Acid and Salicylic Acid on Ultraviolet RadiationInduced Erythema, DNA Damage and Sunburn Cell Formation in Human Skin, Journal of Dermatological Science, 2009 July