Glycolic & Lactic Acids – Why Do We Love Alpha Hydroxy Acids?
Glycolic & Lactic Acids – Why Do We Love Alpha Hydroxy Acids?
A-HA honey... We might not all be Kanye but we were bound to fall in love them! And that’s because AHAs have been our superheroes for the past few decades. Their effect on skin has been remarkable!
Alpha Hydroxy Acids (or AHAs) essentially originate from foods. They can be obtained from their natural sources or made synthetically. 99% of cosmetic products that we use contain synthetically obtained AHAs. The most widely used types of AHAs that you’ve probably heard of, are glycolic and lactic acids. They’re also the most effective. In low concentrations (less than 3%), AHAs work as water-binding agents. At concentrations more than 4% acidity, AHAs have the ability to exfoliate dead skin cells.
Glycolic acid is found in sugar cane and green grapes. Among the AHAs, it has the smallest molecular weight so it penetrates the skin easily and quickly. Therefore, it’s the most effective for treating fine lines, acne, blackheads, dullness, oiliness and even hyper-pigmentation.
Lactic acid is the second smallest molecule. In fact, many researchers believe that this is the new acid of choice since it doesn’t penetrate as deeply as glycolic. However, it still provides a great smoothing effect but with less irritation. It’s found in sour milk, yogurt, blueberries, passion fruit, maple syrup, apples, tomato juice and grapes. In addition to strong moisturizing and exfoliating qualities, it also has the ability to improve skin hydration. With its moisture-retaining properties, lactic acid thickens the epidermis and helps adjust your skin’s pH to normal levels. We’ve all heard of Cleopatra’s famous sour milk baths!
These acids are too large to penetrate the skin, so they work only on and near the skin surface and take longer to show improvement. However, they don’t sting, burn or irritate the skin.
The main benefit of AHAs is their ability to exfoliate the skin. They essentially remove the “glue” from the upper layer of skin that holds onto the old, dead skin cells. By removing that top layer of skin, AHAs help new skin growth. As your skin replenishes itself, it produces more moisture. This is because new skin cells that make up outermost layer of the epidermis, contain higher levels of NMF (Natural Moisturising Factor). NMF is your skin’s self-moisturizing tool. It’s made up of a mixture of water-soluble compounds such as amino acids, which bind to water and hold onto it.
You can achieve even better results by using AHAs in combination with other substances. For example, vitamins A and E enhance anti-oxidation, brightening and toning effects. Whereas hyaluronic acid helps to increase the moisturizing effect.
Most skin types (even those with rosacea or high sensitivity), can benefit from some form of AHA. However, you need to be diligent when using AHAs and pick acidity levels suitable to your skin condition/type. The Cosmetic Ingredient Review (CIR) recommends that the AHA concentration in cosmetic products does not exceed 10%, and has a pH of more than 3.5. If you’ve never used AHAs before, start with a product containing a low concentration. I suggest you carry out a patch test first as some sensitive skins aren’t tolerant to AHAs. You should always apply the product containing AHA first and then after its fully absorbed, use your moisturiser/lotion.
Oily skin provides a fertile environment for acne-causing bacteria. When AHAs exfoliate your skin, they purify excretory ducts of the sebaceous glands removing the skin’s ‘shine’. This helps to reduce sebum (oil) production, unclog pores and subsequently prevent formation of acne. Some acne clearing products often contain both AHAs and Salicylic Acid (BHA), which acts as an anti-inflammatory agent.
There are various moisture absorbing substances (amino acids, urea, etc.) that live on the surface of our skin. They are called NMF (Natural Moisturizing Factor). These substances draw water from the surrounding air, absorb it like a sponge, and then hydrate our skin. AHAs dissolve proteins into amino acids, and thereby enhance the hygroscopic (water absorbing) properties of NMF. AHAs effectively remove old skin layers, facilitating better penetration of moisturizing products into the skin. In addition, AHA’s exfoliating effect considerably softens rough, dry skin and restores normal skin pattern.
Old skin layers prevent penetration of nutrients necessary for the regeneration and protection of ageing skin. As AHAs exfoliate they remove this old skin, stimulating normal regeneration of skin cells. AHAs stimulate fibroblasts (connective tissue cells), which are responsible for the production of hyaluronic acid, collagen and elastin. Fine wrinkles appear considerably smoother, and deep wrinkles become much less pronounced.
By removing dead hyper-pigmented cells, AHAs progressively decrease hyper-pigmentation. In addition to the exfoliating effect, citric and tartaric acids have a whitening effect. Moreover, active removal of old skin from the surface facilitates better penetration of skin brightening products and increases their efficiency.
You shouldn’t use AHAs if you have increased skin sensitivity, a fresh injury, herpes or you suffer from spider veins. Stop using AHAs if you see signs of any adverse reaction, such as burning, redness, pain or increased sensitivity to sunlight.
You should never combine products containing retinoids (retinol) with products containing AHAs. Apply retinol based products in the evening and AHA based products in the morning.
And most importantly, be sure to use sunscreen, regardless of the time of year. Avoid using AHAs altogether if you are planning to spend a lot of time in the sun.
If you read my previous posts, you would know that I’m a total AHAs addict. My skin is very moody and its condition constantly changes forcing me to vary my skincare on a regular basis. However, AHA products never let me down. No matter how my skin feels, they always help. I’m currently combating acne and dry skin so I’m using SkinCeuticals Blemish Age Cleansing Gel together with Sunday Riley Good Genes which I love! It’s a treatment that smooths, refines, clarifies and brightens your skin as well as improving the thickness and elasticity. I use it as a serum under my moisturiser. It contains Lactic Acid, which helps to reduce the appearance of fine lines and wrinkles; Liquorice to combat uneven skin tone; Lemongrass to improve circulation and protect from environmental aggressors; and Sunday Riley’s patented NV-5 Ageless Complex to wage war on the early signs of ageing.