Why sensitive skin types should use lactic acid

Rumour has it that Cleopatra, Queen of Egypt (and OG beauty queen), bathed in sour goat’s milk to keep her skin looking glowy and youthful. Super casual, we know. But while it sounds gross, it turns out she was actually onto something.

You see, when milk sours, bacteria convert the sugar lactose into lactic acid - an alpha hydroxy acid (AHA). And as any good beauty geek would know, when AHAs like lactic acid are applied to the skin, they promote cell turnover, stimulate collagen renewal and encourage smoother, clearer skin.

The best part? Lactic acids are a good all-rounder when it comes to specific skin types, including sensitive skin and acne-prone skin. This means if you’re struggling to incorporate actives like glycolic acid or salicylic acid into your skin routine (these powerful ingredients aren’t suitable for all skin types), you can still reap the same kind of benefits with this gentle exfoliant.

Considering giving it a go? We break down everything you need to know about lactic acid and share the best lactic acid skin care to try.

What is lactic acid?
“Otherwise known as an alpha-hydroxy acid (AHA), lactic acid is a milk-derived gentle acid that helps to exfoliate dead skin cells and other contaminants from the skin,” explains dermal therapist Dr Giulia D'Anna from Dermal Distinction. “Lactic acid is found in many skin care products, both in retail and professional lines. It is a universally beneficial ingredient.”

What skin types should use lactic acid?
According to Dr D’Anna, lactic acid benefits all skin types, “Lactic acid is good for more mature skin, acne-prone skin or sensitive skin types. It really is a good all-rounder.”

Why lactic acid is the best AHA for sensitive skin
“Lactic acid is better suited to a sensitised skin than glycolic acid or salicylic acid. The larger molecule size means that it tends to only produce results in the upper and outer layers of the skin, leaving the deeper layers intact. Lactic acid also has water-binding properties, leaving the skin more hydrated and feeling super soft after use,” says Dr D’Anna.

Lactic acid is available is a wide range of concentrations, making it both a great beginner and advanced AHA. “Products that are formulated for sensitive skin tend to have lower concentrations of lactic acid than those formulated for normal skin types. Your skin or dermal therapist will guide you to make the best choices here.”
 
The benefits of lactic acid for skin
As Dr D’Anna has mentioned, lactic acid is a serious over-achiever. When applied to the skin it can minimise the appearance of pigmentation, improve hydration and prevent congestion. “Lactic acid’s water-binding properties means that as the lactic acid penetrates into the skin, water will be pulled in, too,” explains Dr D’Anna. “Afterwards, the skin feels soft, leaving less obvious fine lines as the hydration of skin improves.”

“Lactic acid may also help lighten skin pigmentation or discolouration. This is because the surface skin cells containing contaminants and old ‘tan’ are gently exfoliated off. It can also visibly firm skin as it renews the surface, leaving it with a smoother texture. Some body moisturisers also contain lactic acid, which can help to reduce the number of ingrown hairs that you might encounter after waxing or shaving,” adds Dr D’Anna. We like Dr Barbara Sturm Anti-Aging Body Cream.

How often should you use lactic acid in your skin care routine?
While lactic acid is certainly one of the gentler acids kicking around, you shouldn’t go too crazy. Overuse, or use of higher concentrations on the regular, can still lead to irritated skin. “I use lactic acid in both my cleanser and pigment-inhibiting serums every day. However, all my skin care is pH balanced and contain only traces of lactic acid so that I am not stripping my skin. Overdoing the use of exfoliants or acids is a definite no-no,” warns Dr D’Anna.

“Higher concentrations of lactic acid (or glycolic or salicylic for that matter), should not be used more than once a week. It is important that we give the skin time to renew and replace, before we exfoliate off more dead skin cells. Otherwise we get to a point where there are no dead skin cells available to protect our skin, and this leads to sensitivity and problematic skin.”

What are the best lactic acid products to use?
When it comes to deciding which kind of lactic acid product is right for you, Dr D’Anna recommends looking both at the percentage and pH of the ingredient. At-home products containing lactic acid should contain about 10 per cent or less. As for the pH, Dr D’Anna says, “Good cosmeceutical skin care lines will ensure that the pH of the formulation is both stable and sits somewhere between pH 3.5 and 5.5. This leaves the normal skin pH balanced, reducing redness or sensitivity.”

Confused if this is the right ingredient for your skin types? Consult an expert. “A dermal therapist can determine which is the best AHA or BHA for your skin, and also point you in the right direction of which products will achieve the best skin health for you,” says Dr D’Anna. “There are so many different reputable brands on the market these days, spending a fortune is not necessary. Just like a good bra fitting makes your clothes look better, a professional skin analysis can really nut out the best daily routine for your skin to bring out the best health and appearance for your skin.”

If you’re looking for some of the best skin care options containing lactic acid, here are some of our favourites: