The Stratum Corneum Is Not Dead…It Is Very Alive

Posted By: Roccoco Botanicals Published: 09/07/2017 Comments: 0
The Stratum Corneum Is Not Dead…It Is Very Alive

One of the oldest stories still being spread even by Dermatologists is that the stratum corneum is dead.  This could not be further from the truth.  The assertion that it is dead comes from research that is over 30 years old.  One of the issues in any industry is the failure of any expert to keep up to date with current scientific knowledge.  This is why Roccoco is committed to continual ongoing education and research.

This morning I watched a video that was posted 7 months ago from a Dermatologist.  The information in there was partially correct and partly wrong as well.  The post was regarding the use of acids in skin care.  It was a general video and not specific to acne.  In true Sagitarrian style I spoke the truth, which some did not like.  However, our mission at Roccoco is to educate, when I see information being shared that isn’t completely true then I feel morally obliged to correct that information so people do not remain confused.  My comments on Instagram had nothing to do with acne and the use of acids and were simply about the incorrect information that was said.

The use of alpha hydroxy acids in skin care emerged about 30 years ago.  For those who suffered from acne at the time they where praised for their ability to get skin clear.  Though over the next decade we saw acids in everything.  We had clients using acid cleansers, acid toners and acid moisturisers.  The end result was a highly sensitized skin and an epidemic of over exfoliation.  Surely if a little is good, a lot must be better.  We then had a new era of skin….the compromised sensitive skin.

My comments on this video were that the stratum corneum is not dead and that glycolic acid does not work by dissolving desmosomes.  Both of which are correct.  Apparently I am now causing a storm in a tea cup simply because I stated that the doctor was not up to date with research (which is evidence by her comments).  The rest of the information in the video was correct and please note that it was stated that “acids need to be in balance” which is extremely important.  Which brings us back to any alpha hydroxy acids over 8% disrupt the skin barrier.

Stratum Corneum

Stratum Corneum

Many people think that if it is dead then it doesn’t really have any function, which as research has shown is grossly incorrect.  The stratum corneum is involved in the following functions in the skin [1]

1 permeability ( this is basically what is allows in and out of the skin.  It is our protective barrier)
2 anti-microbial (The skin cells are responsible for providing us with bacterial defence)
3 anti-oxidant (they regulate the antioxidant status of the skin)
4 cohesion (integrity) – desquamation (shedding)
5 mechanical/rheological
6 chemical, exclusion of antigens
7 psychosensory
8 hydration (the stratum corneum also plays a part in how hydrated your skin is)
9 protection against electromagnetic radiation
10 initiation of inflammation (cytokine activation) – premature removal incites inflammation.

This lifeless layer has a massive impact on the health of our skin.  It is responsible for mounting inflammation and also keeping our skin soft and supple.  It is responsible for regulating our skins antioxidant defence network as well.

Dr Albert Kligman is the grandfather of corneotherapy.  Corneotherapy is what Roccoco practice.  It is called the outside in theory.  This simply means that by focusing on the skin barrier repairing and avoiding peeling the skin repairs itself.  For those of you who are holistic, I am sure you also believe that our bodies are capable of healing themselves if given the chance.  The issue is that many cosmetics on the market now can interfere with this function.  If we allow the skin to heal, it will shut down the inflammatory processes in the skin that should not be occurring.  Eczema and psoriasis are one of the many instances where you see this happening


“In my paper of 1964, which established that the horny layer was a tissue made up of corneocytes, I could not have dreamed of the spectacular advances that have been brought to light by an international school of corneobiologists. I did not go any further than asserting that the stratum was a cellular barrier, theend product of a viable epidermis whose raison d’etre was to produce the dead stratum corneum…I did not have the vision to foresee that the stratum corneum would become very much alive.”

—Albert M. Kligman, MD


The quotation comes from Dr. Albert Kligman.  It comes from a textbook chapter entitled “A Brief History of How the Stratum Corneum Became Alive”.   This was an important turning point in the history of dermatological research.  The previously held belief was that the stratum corneum is dead. That they had no function other than protection and that they where not involved in cellular processes.  This thought was entrenched in mainstream thinking.  Many dermatologists still believe this, but that doesn’t make it true.  There are many who comment that I state information that is completely different to others in the industry.  The reason being is simply because we are up to date with current research.  We don’t follow dogma from 30 years ago.

One landmark publication that proved to be a major milestone in the history of relevant SC science was the seminal paper by Dr. Albert Kligman entitled, “Biology of the Stratum Corneum,” which was published in 1964 [2].   This publication refuted the dogma that the stratum corneum was dead and provided new information.


Our second comment was surrounding how Alpha Hydroxy Acids Work

AHAs work by interacting with a membrane protein in the skin cells. They tested glycolic acid and found that it enters into keratinocytes and generates free protons. The acidic conditions activates an ion channel in the cells membrane protein which leads to a flow of calcium ions into the cell and ultimately leads to cell death due to it becoming overloaded.

The belief that they worked by dissolving desmosomes is outdated research and not current.  They don’t work like that at all.  Alpha hydroxy acids work by changing the calcium gradient within the cell.  The influx of calcium literally causes the cell to explode and shed away.  The study was done 5 years ago.  5 years is not considered new research it is older research in the scope of things.

Glycolic acid, the smallest AHA molecule with the greatest bioavailability, penetrates skin the easiest, accounting for its popularity in cosmetic applications [4 –6]. The bioavailability of glycolic acid usually depends on its concentration and hence the pH level it produces [7–10]. Despite the importance and prevalence of glycolic acid and other AHAs, the mechanism by which they are sensed by the skin is poorly understood.


About the Author

Jacine Greenwood

Jacine Greenwood is an internationally recognised educator who is known within the industry for her up to date knowledge and her ability to deliver training in an easy to understand method.  Jacine is the founder of Roccoco Botanicals and the founder of Educated Therapists.  Educated Therapists is a training portal for Estheticians requiring advanced skin knowledge.

Jacine holds 6 Diplomas and 2 Bachelor Degrees and her knowledge is well respected by her peers.  She is also a qualified Cosmetic Chemist, Esthetician and Aromatherapist.  With over 22 years experience in the industry and a background of cosmetic formulation, Jacine has an immense knowledge of current trends in research and new developments in the industry.

Jacine has been continually educating herself in all aspects of skin function and cosmetic chemistry for the past 22 years.  Jacine’s knowledge is current and has a vast knowledge of the active ingredients that are being released onto the market.





Kligman, A. “Corneobiology and Corneotherapy – a final chapter” International Journal of Cosmetic Science (2011), 33, 197-209.

Elias PM. The epidermal permeability barrier: from Saran Wrap to biosensor. In: Elias PM, Feingold KR, eds. Skin Barrier. New York: Taylor & Francis; 2006:25–32.

Xu Cao, Fan Yang, Jie Zheng, and KeWei Wang. ‘Intracellular Proton-mediated Activation of TRPV3 Channels Accounts for the Exfoliation Effect of -Hydroxyl Acids on Keratinocytes’.  The Journal of Biological Chemistry VOL 287, No 31, pp 25905–25916.

Moy, L. S., Murad, H., and Moy, R. L. (1993) Glycolic acid peels for the treatment of wrinkles and photoaging. J. Dermatol. Surg. Oncol. 19, 243–246

Moy, L. S., Howe, K., and Moy, R. L. (1996) Glycolic acid modulation of collagen production in human skin fibroblast cultures in vitro. Dermatol. Surg. 22, 439 – 441

Bergfeld, W., Tung, R., Vidimos, A., Vllanki, L., Remzi, B., and Stanton- Hicks, U. (1997) Improving the cosmetic appearance of photoaged skin with glycolic acid. J. Am. Acad. Dermatol. 36, 1011–1013

Kim, S. J., and Won, Y. H. (1998) The effect of glycolic acid on cultured human skin fibroblasts. Cell proliferative effect and increased collagen synthesis. J. dermatol. 25, 85– 89

Thueson, D. O., Chan, E. K., Oechsli, L. M., and Hahn, G. S. (1998) The roles of pH and concentration in lactic acid-induced stimulation of epidermal turnover. Dermatol. Surg. 24, 641– 645

DiNardo,J.C.,Grove,G.L.,and Moy,L.S.(1996)Clinical and histological effects of glycolic acid at different concentrations and pH levels. Dermatol Surg. 22, 421– 424

Gutknecht,J.,andTosteson,D.C.(1973)Diffusion of weak acids across lipid bilayer membranes. Effects of chemical reactions in the unstirred layers. Science 182, 1258 –126.

Hamamoto, T., Takumida, M., Hirakawa, K., Takeno, S., and Tatsukawa, T. (2008) Localization of transient receptor potential channel vanilloid subfamilies in the mouse larynx. Acta Otolaryngolog. 128, 685– 693

Peier, A. M., Reeve, A. J., Andersson, D. A., Moqrich, A., Earley, T. J., Hergarden, A. C., Story, G. M., Colley, S., Hogenesch, J. B., McIntyre, P., Bevan, S., and Patapoutian, A. (2002) A heat-sensitive TRP channel expressed in keratinocytes. Science 296, 2046 –2049.


Tags: AHA, alpha hydroxy acids, Dr Kligman, glycolic, salicylic acid, stratum corneum, TRPV3


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