By Dr Michel A. Hegi, PhD. Senior scientist for The Skin Society
BHA work better on Acne because is Oil Soluble!
Glycolic acid is perhaps the best-known of a group of chemicals called fruit acids or alpha-hydroxy acids (AHA). It is derived from sugar cane, so it can be considered a natural product. Citric acid from oranges and other citrus fruits and lactic acid from Milk also fall under the same classification as Alpha glycolic acid.
Glycolic acid works as an exfoliating agent because of its high acidity but easy solubility. When placed on the skin as part of an exfoliating cream or gel, glycolic acid goes under the damaged upper layers of skin and destroys the ‘glue’ which holds dead skin to the surface.
Glycolic acid as a sloughing effect on the skin; (removal of dead cells) by accelerating the normal rate of sloughing it help the regeneration of your skin by growing new cells faster.
Studies of percentages of Glycolic acid usage in commercial, over the counter cream and lotion products found that: 5% to be a good average. The reason behind this is as follow: As you increase the acid content the ph goes down. Low ph burn your skin so to raise the ph to an acceptable level you have to ad Calcium hydroxide and it defeat the purpose of the high content of acid.
Alpha or Beta the Difference between Alpha and Beta Hydroxy Acids
There is only one beta hydroxy acid: salicylic acid. The main difference between alpha hydroxy acids and beta hydroxy acid is their lipid (oil) solubility. Alpha hydroxy acids are water soluble only, while beta hydroxy acid is lipid (oil) soluble. This means that beta hydroxy acid is able to penetrate into the pore which contains sebum and exfoliate the dead skin cells that are built up inside the pore. Because of this difference in properties, beta hydroxy acid is better used on oily skin with blackheads and whiteheads. Alpha hydroxy acids are better used on thickened, sun-damaged skin where breakouts are not a problem. In theory it penetrates the skin faster.
Beta vs. Alpha Hydroxy acids
Studies conducted to test the efficacy of Alpha versus Beta glycolic acid on normal skin are inconclusive at best. Both acids seem to be equally effective in their exfoliating power; however the effect from Salicylic acid showed more sustained effectiveness and less adverse effect than AHA. Other studies found that the ph at which Glycolic acids are the most effective is below ph of 4. But it may give you a burning sensation when you apply it on your skin. In medical offices up to 80% Glycolic acid and at much lower ph. have been used for peel but for the general use, I will suggest around 5% in cream and lotion and 10% in do it yourself peels. But for peels be sure to follow the manufacturer’s instructions conscientiously! Too long of an exposure may give you temporary redness. For more anti Aging Products look at: http://www.theskinsociety.com
Michel A. Hegi PhD.
http://www.theskinsociety.com/Acne/Acne.html
http://www.theskinsociety.com/Rosacea/Rosacea-Treatment.html
http://www.theskinsociety.com/Eczema/Eczema.html
http://www.theskinsociety.com/Psoriasis/Psoriasis.html
http://www.theskinsociety.com/Escin/escin-cream.html
