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Alpha, Beta and Mandelic acids

Know the difference!

With increasing research into what causes wrinkles and the effects of photoaging, the use of hydroxy acids has increased greatly in popularity. Alpha hydroxy acids (AHA's) have been used for thousands of years as a skin rejuvenating product. Cleopatra is reported to have bathed in milk (lactic acid) to improve her complexion. Now hydroxy acids are a common additive to numerous skin care products including moisturisers, cleanser, toners, and masks. There are two types of hydroxy acids - Alpha and Beta. Alpha hydroxy acids are exfoliants derived from fruit and milk sugars such as glycolic acid produced from sugar cane and lactic acid produced from milk. There is only one beta hydroxy acid (BHA) - salicylic acid which is usually sourced from the Willow or Popular tree.

The difference between Alpha Hydroxy Acids 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 a beta hydroxy acid is able to penetrate deeper into the pore which contains sebum (oil) and exfoliate the dead skin cells that have built up inside the pore. Because of this difference in properties, beta hydroxy acid is better used on oily skin with pimples and/or blackheads.

Alpha Hydroxy Acids (AHA's)

Alpha hydroxy acids, as stated above, are derived from fruit and milk sugars. The most commonly used alpha hydroxy acids are glycolic acid and lactic acid because they have a special ability to penetrate the skin. They also have the most scientific data on their effectiveness and side effects.

The following are the 6 major types of alpha hydroxy acids found in skincare products and their sources:
Glycolic acid - sugar cane
Lactic acid - milk
Malic acid - apples and pears
Citric acid - oranges and lemons
Tartaric acid - grapes
Mandelic acid - bitter almonds

How Alpha Hydroxy Acids work

Alpha hydroxy acids work mainly as an exfoliant. They cause the cells of the epidermis to become "unglued" allowing the dead skin cells to slough off. Alpha hydroxy acids may even stimulate the production of collagen and elastin. Alpha hydroxy acids are reported to improve wrinkling, roughness, and mottled pigmentation of photodamaged skin after daily application. Ironic because they also can cause sun sensitivity. Alpha hydroxy acids found in skincare products work best in a concentration of 5% to 8% and at a pH of 3 to 4.

Alpha Hydroxy Acids and Irritation

The two major side effects of alpha hydroxy acids are irritation and sun sensitivity. Symptoms of irritation include redness, burning, itching, pain, and possibly scarring. People with darker coloured skin are at a higher risk of scarring and pigment changes with alpha hydroxy acids. The use of alpha and beta hydroxy acids can increase sun sensitivity by 50% causing an interesting dilemma. It appears that alpha and beta hydroxy acids may be able to reverse some of the damage caused by photoaging, but at the same time they make the skin more susceptible to photoaging (sun damage). It is clear that anyone using hydroxy acids must use a good sunscreen that contains UVA and UVB protection and with an SPF of 50.

Beta Hydroxy Acids (BHA's)

How Beta Hydroxy Acids work

Like AHA, BHA works well as an exfoliant by penetrating deep into pores, sloughing off dead skin cells to make room for new ones. They are best used on oily, congested skin due to the fact that they penetrate deeper than AHA's.

Beta hydroxy acid is reported to improve blemishes, acne scarring, wrinkling, roughness, and mottled pigmentation of photodamaged skin after at least 6 months of daily application. Beta hydroxy acid found in skincare products works best in a concentration of 1% to 2% and at a pH of 3 to 4.

Beta Hydroxy Acids and Irritaion

Beta hydroxy acid appears to be less irritating than alpha hydroxy acid even though it penetrates deeper into the pore. This occurs because salicylic acid is derived from acetylsalicylic acid, or aspirin. Aspirin has anti-inflammatory properties, and salicylic acid retains many of these anti-inflammatory properties. Despite this fact, beta hydroxy acid can still cause skin irritation. Symptoms of irritation include redness, burning, itching, pain, and possibly scarring. People with darker colored skin are at a higher risk of scarring pigment changes with beta hydroxy acid.

Using Alpha and Beta Hydroxy Acids's

Alpha and Beta hydroxy acid is found in a variety of skin care products including moisturisers, cleansers, eye cream, sunscreen, and foundations. Here are some guidelines to use when trying to decide which hydroxy acid formulation to use:
• It is best to pick one product that contains the proper formulation of beta hydroxy acid to use as your exfoliant, and then choose other skin care products or cosmetics that don't contain hydroxy acids to reduce the likelihood of skin irritation.
• Using an alpha hydroxy acid in a moisturiser base may be the best combination of products. However products containing AHA's and BHA's should be used at night!
• Cleansers containing AHA's and BHA's have little or no effective because the hydroxy acid must be absorbed in the skin to work. Cleansers are washed off before this absorption occurs. Cleansers containing AHA's or BHA's should be left on the skin for a minute or 2.
• At this time there are no effective products that combine hydroxy acids and sunscreen, because sunscreen is not stable at the pH required to make the hydroxy acid effective.
• Sunscreen MUST be applied liberally when using an alpha and beta hydroxy acid product. The sunscreen should have an SPF of at least 30 for UVB protection and contain avobenzone, titanium dioxide, or zinc oxide for UVA protection.
• Alpha hydroxy acids work best in a concentration of 5% to 8% and at a pH of 3 to 4. Unfortunately, cosmetic manufacturers are not required to provide concentration information on the label. As a general rule of thumb, having the alpha hydroxy acid listed as the second or third ingredient on the list makes it more likely it contains the proper concentration. The only way to know for sure the pH of a product is to test with a pH strip.
• Beta hydroxy acid works best in a concentration of 1% to 2% and at a pH of 3 to 4. Unlike alpha hydroxy acid that must be listed in the top 3 ingredients to indicate the appropriate concentration, beta hydroxy acid can be listed in the middle or even towards the bottom of the ingredient list because it is effective at lower concentrations.

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