To the uninitiated exfoliating acids can sound scary. Acids? On our face? But like a pH balanced cleanser, they can transform your routine and skin. Oily, combination, acne-prone, dull, aging, dry, sensitive, no matter the condition of your skin, it can benefit from some gentle exfoliation. It goes without saying, if you suffer from any skin or medical condition, consult your doctor.
Alpha Hydroxy Acids
Most suitable for: dry, sun-damaged, normal, aging, acne-prone skin.
Alpha Hydroxy acids include Glycolic, Lactic, Mandelic, Malic, Citric and Tartaric acids. They are normally derived from plant sources (or milk in case of Lactic acid), but nowadays most Alpha hydroxy acids used in skincare products are synthetically derived.
AHAs are water soluble and work on the surface of the skin (at the outermost layer of epidermis). They work by dissolving the bonds that hold the dead skin cells together and the skin sheds. AHAs also increase the cell turnover and influence the structure of new skin. They work as hydroscopic agents, which means they bind the moisture to the skin and hydrate it. The end result is softer, smoother skin and more even skin tone.
We will focus on the most popular – Glycolic, Lactic and Mandelic.
Glycolic acid – derived from sugar cane and smallest in size. It means it can penetrate deeper than other AHAs. On one hand that is good because it means it is effective. But if you have sensitive skin, Glycolic acid might be too strong or your skin might need longer to adjust.
Lactic acid – derived from milk and larger in size than Glycolic acid. That means that is slower to penetrate the skin. It is more suitable for people with dry, dehydrated and sensitive skin and/or if you do not tolerate Glycolic acid.
Mandelic acid – derived from bitter almonds. Mandelic acid molecules are bigger than Glycolic and Lactic acid. That means you still get the benefits of exfoliation, but with minimum irritation. It has natural antibiotic and antibacterial properties and regulates sebum production. Mandelic acid works on inflammatory pustular, comedonal and papular acne. It also works better for darker skin tones as there is less risk it will cause pigmentation issues.
Beta Hydroxy Acid
Most suitable for: oily, combination, congested, rough and bumpy skin.
Beta Hydroxy acid is Salicylic acid. It is an oil soluble acid. BHA also works on the surface by dissolving the bonds that hold dead skin cells together. But because Beta Hydroxy acid is oil soluble, it can penetrate deeper and clear out pores and excess oil.
Poly Hydroxy Acid
Most suitable for: sensitive, dry, aging, normal skin.
Poly Hydroxy acids are a new generation of Alpha Hydroxy acids and include Lactobionic acid, Gluconolactone and Galactose. They are larger in molecular size than AHAs which means they are slower to penetrate the skin and less likely to cause irritation. PHAs are natural humectants and bind water to the skin. Due to their molecular size and anti-inflammatory properties they are suitable to use for sensitive skin types (people who have been diagnosed with rosacea and atopic dermatitis can try PHAs if they are after gentle exfoliation).
Have you tried exfoliating acids? What is your favourite type? Are you happy with the results?