Some of the most frequent questions I am asked concern acids – specifically glycolic. As more and more people embrace acids in all their glory, I thought a few facts from industry expert Lorna Bowes would be interesting. Lorna is an RGN with a specialty in dermatology and advises and trains doctors and aestheticians around the globe. There is nothing about acids and peels this woman does not know.

Myth: Glycolic thins the skin.
Fact: Glycolic Acid thickens the skin.
The first study on hydroxy acids was on the modulation of keratinisation with ichthyosis as the model:
‘Van Scott EJ, Yu RJ: Control of Keratinization with a-Hydroxy Acids and Related Compounds. Archives of Dermatology 110: 586-590, 1974’.
This led to understanding that glycolic acid exfoliates and normalises the keratinisation process so that the stratum corneum (outer horny layer of your skin) is more flexible and the excess build up associated with the ageing process is reduced.
However, in 1996 Dr Ditre, a US Dermatologist, published a paper:
‘Ditre CM, Griffin TD, Murphy GF, Sueki H, Telegan B, Johnson WC, Yu RJ, Van Scott EJ.
Effects of alpha hydroxy acids on photo-aged skin: a pilot clinical, histologic and ultrastructural study.
J Am Acad Dermatol 1996; 34:187-95’.
This paper demonstrated that an AHA treated site increased skin thickness by 25%, the rete pattern (junction between epidermis and dermis which in short works like velcro) is improved, elastic fibres are improved, and there is an increase in GAGs as well as an increase in collagen fibre density.

In summary –

Good thing: Glycolic acid thins the outer stratum corneum which becomes too thick as we age.
Good thing: Glycolic acid restores the essential components of the skin that are damaged as we age, leading to a thicker skin that functions more youthfully.

For smoother texture, softer younger looking skin, more evenness of skin tone and clarity, and a fuller, firmer skin with more elasticity and less laxity, use glycolic acid.

Myth: You must use SPF30 or above if using acids as AHAs increase sensitivity to UV light.
Fact: Increases in sunburn cell formation have been documented following AHA use.
However, this effect can be prevented by use of the very lowest level of sunscreen, even as low as an SPF2.
(This fact is merely to reassure you that if you use acids, you’re not burning your face off when you go outside, not to encourage you to cease SPF usage, which you will still need for the usual reasons! CRH)

Myth: AHAs diminish skin barrier function
Fact: US FDA studies have not shown an increase in the absorption of studied materials which means that skin barrier function is not decreased. Further studies have demonstrated AHA-related improvements in skin barrier function.

Myth: AHAs cause skin irritation
Fact: AHAs are known to occasionally produce transient stinging, especially at higher strengths.
Stinging should be fleeting and should not produce excessive erythema (redness). Mild irritation can be (but is not always) part of the process.

Any Qs let us know in the comments. And thank you Lorna!

More info on Lorna Bowes:

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The views expressed on this site are the author’s own and are provided for informational purposes only. The author makes no warranties about the suitability of any product or treatment referenced or reviewed here for any person other than herself and any reliance placed on these reviews or references by you is done so solely at your own risk. Nothing on this site shall be construed as providing dermatological, medical or other such advice and you are always advised to seek the advice of a suitable professional should you have any such concerns.