Alpha Hydroxy Acid
The mention of acids in any context, brings along with it the various toxic aspects of it. As students, we learn about acids and their corrosive nature and how one needs to be careful while handling these. Well it is necessary to maintain caution while handling acids, but these acids are an important part of human life. Some natural acids are present in our body that help us survive whereas some are synthetic that a re used in a variety of products. One such group of acids that's useful to us is alpha hydroxy acids. These acids consist of a variety of important acids such as glycolic acid, lactic acid and citric acid.
What are Alpha Hydroxy Acids?
These are carboxylic acids (acids with -COOH group) with a hydroxyl (-OH) group) on the adjacent carbon or the alpha carbon, of the carboxylic group. These can be naturally occurring or synthetic. These acids have found a wide range of application in the cosmetic industry as they have proven to be safe on the skin. Due to their acidic nature they act as good reducing agents and therefore play a role in scavenging free radicals. This property has helped them to make a mark in the anti aging creams section to delay the occurrence of wrinkles.
The major acids that are being used currently in the cosmetic industry are glycolic acid, lactic acid, malic acid and citric acid. Here is list of various AHAs.
Glycolic Acid
This acid has the smallest structure in the category of AHA. It is a crystalline solid, soluble in water. It is widely used in various skin care products. The most popular application of this acid is in chemical peels at a concentration of 20 to 70% when prescribed by dermatologists or as low as 10% in home products. Glycolic acid is used for acne, wrinkles, hyper-pigmentation and hyperkeratosis. When used in keratosis, glycolic acid weakens the binding of lipids to the dead skin cells and thus ex foliates the skin.
Lactic Acid
The main source of this acid is sour milk. Lactic acid is also used an exfoliating agent, however it is very gentle and therefore preferred for sensitive skin. More importantly lactic acid acts as a very effective antibacterial agent. It maintains the pH of the skin and thus prevents bacterial infections therefore used in antibacterial products. It is used in making lotions for smoothening elbows and heels. Lactic acid has the property of enhancing the absorption of cosmetics such as sunscreen lotions.
Citric Acid
Citric acid is present in fruits such as lemons, oranges and grapefruits. Citric acid is a very effective antioxidant and therefore present in many anti-aging or face lift creams. It is also a good astringent and helps in treatment of nasty spots. It also improves the effectiveness of skin moisturizers. Citric acid is also used in hair care products, It is used in post perm treatment to minimize the odor.
These were the major alpha hydroxy acids used in the cosmetics industry, the rest such as malic acid and tartaric acid are less used in cosmetics as there are certain safety issues while using these on the skin. These carboxylic acids are popularly used in anti-aging creams and are safe to use. However make sure you take a look at the chemical composition of the cosmetics before you use them.
