What Is Lactic Acid? The Essential Skincare Alphabet

Today we are tackling L and the one ingredient, that still gets the most questions, is lactic acid. It’s the type of ingredient that seems suitable for everyone but because it may not work for everyone, is perplexing.

And believe me I know, I have done tonnes of posts on this. Like this one:

Read Lactic Acid vs Retinol here.

That being said, lets get back to basics and explain the absolute essential points you need to know about this sometimes confusing acid.

What is lactic acid?

Lactic acid is one of the most commonly used alpha hydroxy acids in the skincare industry, although they have many similar functionalities to other AHA’s such as; malic acid, citric acid, pyruvic acid, tartaric acid (1).

Read AHA’s vs BHA’s here.

They are used in skincare to chemically exfoliate the skin by breaking the bonds of dead skin cells.

How they do this is elusive still. However, it is believed they do so by removing calcium ions from epidermal cell adhesions by chelation (1).

AHA’s in general became popular because of the rise in interest in anti-aging skincare, which occurred in the 90’s.

It would also be worth noting that, AHA’s exfoliating and anti-aging benefits may be why Cleopatra took milk bath’s to nourish her skin.

Milk contains lactic acid.

Is lactic acid good for skin?

Yes it is!

In fact, the results from this 1996 study (2) shows people who applied 12% lactic acid twice a day for 3 months saw improvement’s in skin smoothness and in the appearance of lines and wrinkles.

However, of course you can be over zealous with anything and especially acids. Your skin care be irritated by it.

If you’re following the advice of the product and still feel stinging/redness, then disregard use and try mandelic acid.

How often should I use lactic acid on my face?

This is completely dependant on the product you bought. Follow the instructions on your product because how much you use will be dependant on the concentration of the brand used.

What skin type is lactic acid good for?

All of them can use this particular acid!

It’s known as the gentler AHA, so it is very much marketed towards sensitive skin but really anyone can use it.

If you’ve never tried chemical exfoliation before, this would be a good place to start.

Product recommendations

Drunk Elephant T.L.C. Sukari Babyfacial

The Ordinary Lactic Acid 10% + HA

BIOSSANCE Squalane + Lactic Acid Resurfacing Night Serum


(1) Tran D, Townley JP, Barnes TM, Greive KA. An antiaging skin care system containing alpha hydroxy acids and vitamins improves the biomechanical parameters of facial skin. Clin Cosmet Investig Dermatol. 2014;8:9-17. Published 2014 Dec 19. doi:10.2147/CCID.S75439

(2) Smith, W. P. (1996). Epidermal and dermal effects of topical lactic acid. Journal of the American Academy of Dermatology35(3), 388-391.

Pictures courtesy of brands

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