Glycolic Acid vs Lactic Acid: Which AHA Would Be Better for Your Skin?

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It’s no secret that exfoliation is key to maintaining a healthy complexion but, when it comes to how you should be exfoliating, things aren’t quite so straight cut.

You first need to pick between physical and chemical exfoliants – if you’ve done your research, you’ll likely lean towards chemical, since these are gentler and far more effective. Then, you’ll need to decide which chemical exfoliant would work best for your skin. Those with acne-prone skin usually favor beta hydroxy acids, or salicylic acid in particular. However, for everyone else, alpha hydroxy acids are the way to go. This brings us to the big question: which is better, glycolic acid or lactic acid? Stick with us and you’ll soon have an answer.

What are Alpha Hydroxy Acids?

Alpha hydroxy acid structure

An alpha hydroxy acid (AHA) is a naturally derived acid that serves to break down the older and rougher skin cells on the surface of the skin. Unlike BHAs, which are oil-soluble and work deep inside the pores, AHAs are water-soluble, making them great for working on the outer layer of the skin.

There are several AHAs out, with the two most effective being glycolic acid and lactic acid.

What is Glycolic Acid?

Glycolic acid comes from sugar cane. Not only does glycolic acid exfoliation remove dead skin cells from the skin’s surface, but it’s also great for increasing collagen production and brightening the skin tone.

What is Lactic Acid?

Lactic acids naturally occur when certain foods are fermented. The ingredient works in a similar way to glycolic acid and is also known for its hydrating properties.

The Similarities Between Glycolic Acid and Lactic Acid

When it comes to exfoliation, both glycolic acid and lactic acid dissolve the glue-like bonds that keep dead skin cells attached to the outer layer of the skin. This allows those cells to fall away, revealing the fresher and smoother skin beneath.

Both acids are also effective at stimulating the cell turnover process. This encourages the skin to produce new cells at a faster rate, resulting in healthier and more resilient skin overall.

Lactic Acid vs Glycolic Acid: The Main Differences

So, if both lactic acid and glycolic acid work in similar ways, what’s the difference between them?

The main difference lies in their molecular size. Glycolic acid consists of smaller molecules than lactic acid, meaning that it’s able to penetrate deeper into the skin to produce changes that are more dramatic. On the other hand, lactic acid molecules are larger, which makes the acid much gentler and less irritating. However, this does also mean that it takes longer to produce a noticeable result.

Which One Should You Choose?

Product serum vitamin C with orange and lemon

When trying to choose a chemical exfoliator, the first thing to consider is your skin type. Those with dry skin or very sensitive skin are usually better suited to lactic acid – glycolic can be a little too irritating. However, those with normal or oily skin can use glycolic acid without any issues.

Next, think about your main skin concerns. If flakiness is a problem, lactic acid will help to hydrate, thanks to its humectant properties. On the other hand, if anti-aging is your game, then the powerful effects of glycolic acid are what you want. Not only will it help to thicken your skin [1], therefore reducing the visibility of fine lines and deeper wrinkles, but it’ll also treat other signs of sun damage on the outer layers of your skin, such as dark spots and a rough skin texture.

Adding AHAs to Your Skincare Routine

Before using any AHA skincare products for the first time, make sure that you perform a patch test. This is essential, since AHAs have the power to seriously aggravate your skin.

When adding an AHA into your skin care routine, it’s always best to start off slow. Use the ingredient just once a week to begin with, before gradually increasing frequency to the recommended amount. If your skin reacts in any way, then stop and give it some time to recover. Over-exfoliation is very real – it can cause damage to your skin for several months, or even longer.

If you also use vitamin C (l-ascorbic acid), then change up your skincare routine so that you’re not using both vitamin C and an AHA at the same time. AHAs destabilize the vitamin, rendering it useless. Retinol is another one to avoid when using AHAs – the two combined can lead to irritated and dry skin since retinol also has exfoliating effects.

Keep in mind that, whichever acid you use, exfoliation makes your skin more vulnerable to sun damage. However, since glycolic acid can have a thinning effect on the skin at first, it makes sun damage even more likely [2]. This makes a good sunscreen extremely important.

Young successful business womanshowing off her smooth skin

FAQs

Can I use glycolic acid and lactic acid together?

While, technically, there may be nothing wrong with using glycolic acid and lactic acid together, there’s also no need to do this. If you’re looking for stronger or weaker results, then consider a different concentration of the acid that you’re currently using.

Do glycolic and lactic acid do the same thing?

In a way, glycolic and lactic acid do the same thing – they both exfoliate away dead skin cells. However, they do also each have their own individual benefits, which is why it’s important to choose the right one for your skin.

Is glycolic acid safe for sensitive skin?

If your skin is only mildly sensitive, a low-concentration of glycolic acid could be perfectly safe. On the other hand, if your skin is extremely sensitive, glycolic acid would be far too irritating. Lactic acid would be a much better choice.

Summary

Although glycolic acid and lactic acid may seem pretty similar at first, there are a few major differences between them that make it much easier to decide which would be better for your skin. For dryness and sensitivities, lactic is the way to go, while those with sun damage, oily skin, or aging concerns should consider glycolic. Once you’ve found the perfect AHA for your skin, stick with it – regular and consistent usage is what’s needed to really transform your complexion.

References

[1] https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1524-4725.1999.08129.x
[2] https://www.ncbi.nlm.nih.gov/pubmed/12713551#

Avatar for Megan Foley

Megan has been a freelance writer and editor since 2016. In that time, she’s penned a diverse collection of articles for online publication, with a focus on skincare and beauty. From in-depth product reviews to concise marketing content, Megan is passionate about developing content that informs, entertains, and inspires.