Glycolic Acid vs Lactic Acid

As a long time beauty writer, I’ve covered almost every skincare ingredient under the sun, from the most-talked-about ones (like niacinamide – The Ordinary niacinamide is one of our favs) to beauty hypes in recent years — hey, bakuchiol, I’m looking at you. 😉

Safe to say, I’ve been around the block with chemical exfoliants, like glycolic acid and lactic acid. This makes me the perfect person to dish out the good stuff about them. Readon to find out the benefits of glycolic acid vs. lactic acid and which is better for your skin type.

What is glycolic acid?

Ah, glycolic acid, one of the OGs in the world of alpha-hydroxy acids (AHAs). This popular chemical exfoliant is derived from sugarcanes, making it a fruit-based acid.

Glycolic acid has the smallest molecular weight relative to other chemical exfoliants. As such, it easily sinks into your skin. For that reason, glycolic acid is one of the most potent AHAs. Many people use it for hyperpigmentation, fine lines, and textural scars.

If you’re interested in giving this AHA a shot, try the Pixi Glow Tonic that’s formulated with 5% glycolic acid.

Best for: Acne, scarring, hyperpigmentation, fine lines, and wrinkles.

What is lactic acid?

Topical lactic acid is also called sodium lactate. This beauty ingredient is often derived from sour milk or synthetic equivalents. That said, your skin also produces it. According to a 2018 review, lactic acid is part of “the skin’s natural moisturizing complex.” Safe to say, it’s excellent as a moisturizing ingredient.

Ready to try your hand at lactic acid? The Ordinary Lactic Acid 5% + HA is a good starting point. What if your skin is already well-acquainted with a high-strength lactic acid formula? Go with The Ordinary Lactic Acid 10% + HA instead.

Best for: Acne, hyperpigmentation, and fine lines.

Skincare benefits of glycolic acid vs lactic acid

There’s a lot of talk about the skincare benefits of glycolic acid and lactic acid. Like how glycolic acid can help smooth out an uneven skin texture. Or how lactic acid exfoliates while hydrating your skin at the same time.

So, what’s the deal with both AHAs? Are they as formidable as the beauty community makes them out to be? Keep reading for the answers to your most pressing questions.

Acne and scarring

Whiteheads and pimples have met their match with glycolic acid and lactic acid.

That’s because AHAs are a class of keratolytic agents. This is to say they unglue the bonds holding dead skin cells together. As you can imagine, it’s now easier to clear out the acne-inducing gunk from your pores. And you know what cleaner pores entail — a “poreless” complexion and fewer breakouts.

And the proof’s in the pudding. Research shows a 70% glycolic acid peel improved comedogenic acne and superficial scarring. Year-long application of 5% lactic acid was also effective in reducing breakouts.

As you can see, low acid concentrations work as well as high-strength formulas. The trick is to be patient. You can always start with lower acid concentrations, say, 4-5%. Then, work your way up to higher concentrations.


Post-inflammatory hyperpigmentation is a common obstacle toward clear-looking skin. It can take the form of post-acne blemishes and pregnancy-induced melasma. Or even the dreaded age spots. But, not to worry, as glycolic acid and lactic acid are here to help.

The root cause of pigmented skin lies in the excess melanin content in the affected areas. Glycolic acid penetrates the skin barrier to disrupt the melanin deposits. That’s why it’s often used to treat hyperpigmentation to great effect.

Still, not everyone can tolerate the skin-sensitizing effects of glycolic acid. If that’s the case, research recommends lactic acid as a gentler depigmenting treatment.

A small study involving 20 patients with melasma examined the effects of lactic acid peel treatment. At the end of 12 weeks, participants saw significant improvement in their hyperpigmentation. Moreover, they observed minimal side effects and only reported a burning sensation.

Note: Both glycolic acid and lactic acid are generally safe for pregnant women. For peace of mind, consult your primary doctor or dermatologist before use.

Fine lines and wrinkles

Did you know that glycolic acid and lactic acid promote collagen synthesis? This is great news as our skin’s collagen-producing capabilities decline with age. In other words, these AHAs may be your golden tickets to younger-looking skin.

Scientific evidence indicates that glycolic acid enhances Type 1 collagen mRNA. mRNA tells your skin cells to produce Type 1 collagen proteins. For the uninitiated, Type I and III collagen are present in your skin. On top of that, glycolic acid supercharges your skin’s hyaluronic acid content. This helps your skin to stay moisturized.

So, what about the anti-aging prowess of lactic acid?

When you apply 12% lactic acid for three months, it boosts skin firmness and smoothness. This way, you can look forward to less visible fine lines and wrinkles. 5% lactic acid also mimics these skin-beneficial results, but only on the surface level.

Glycolic vs lactic acid
Photo by The Ordinary / Instagram

Which is better, glycolic or lactic acid?

At this juncture, you may wonder, “Between glycolic acid and lactic acid, which is better for my skin?” The answer depends on how sensitive your skin is, and how fast you want results from your skincare regime.

Remember, glycolic acid has a low molecular weight. It bypasses your skin barrier without any trouble to work its magic from the inside out. That’s why you may see faster results with glycolic acid. Nevertheless, it’s more likely to irritate your skin. Many people often complain of tingling, dryness, peeling, and even burning.

On the other side of the beauty coin, lactic acid has a larger molecular weight. As a result, it can’t penetrate your skin layers as deeply as glycolic acid. In other words, lactic acid is less likely to cause skin sensitivity.

For this reason, lactic acid is often perceived as a gentler exfoliant than glycolic acid. Moisturizing lactic acid can also negate some of the side effects associated with glycolic acid. For example, dryness, flaking, and peeling.

The tradeoff is that lactic acid works more slowly than glycolic acid. The former’s effectiveness is also targeted at the outermost skin layer. Still, it’s a potent chemical exfoliant on its own.

Can you use glycolic and lactic acid together?

We get it. You want to use glycolic acid and lactic acid together to get the best of both worlds. But the question is, can you — and should you?

The answer: Technically, yes. After all, there are countless products on the market that are a combination of the two acids. Case in point: ISNTREE Clear Skin 8% AHA Essence.

Keep in mind, though, that these products are carefully formulated at the right percentages of glycolic acid and lactic acid. The formulas also generally incorporate other skin-soothing ingredients. Think aloe vera and hyaluronic acid to minimize acid-induced skin irritation.

You should also know that using both acids at the same time may overwhelm your skin. This is especially so if you’re new to glycolic acid and lactic acid. Product formulations at higher acid concentrations can also easily lead to the side effects we’ve covered earlier.

If you want to layer glycolic acid and lactic acid together, it’s best to start at a low concentration range of 4-5%. You can also use it with other hydrating products like snail mucin and propolis extract. Such ingredients help tamp down the acids’ intensity as needed.

On top of that, play to the strength of your skin type. For example, normal, oily, and mature skin types may tolerate this combination well. Meanwhile, dry to sensitive skin types may find the blend a little too much. The same goes for those struggling with skin issues like rosacea and eczema.

So what should you not mix glycolic acid and lactic acid with? For starters, anything vitamin A-related — think retinol and retinoids. AHAs also never play well with vitamin C-infused products and acne treatments like benzoyl peroxide.

In case you forget, here’s your friendly reminder to apply sunscreen — something you should already be doing on the regular. This step applies even when you don’t have either acid on your face. The reason being, AHAs can cause sun sensitivity for up to a week afterward.

So, whether it’s rain or shine, indoors or outdoors, wear SPF 30 and above. Also, remember to reapply your sunscreen as regularly as needed, depending on your daily routine.

Which acid is best for my skin type?

Glycolic acid, with its penchant for skin sensitivity, is better tolerated by normal to oily skin types. Because glycolic acid can work deeper into the skin layer, it’s generally recommended for uneven skin texture. In which case, if you have acne scars and wrinkles, glycolic acid is for you.

On the other hand, lactic acid is a gentler exfoliant that’s suitable for dry to sensitive skin types. Its larger molecular weight and moisturizing properties translate to lower odds of skin irritation.

As always, do a patch test to see how your skin reacts to each acid. Then, apply it to your face. If all goes well, slowly increase the concentration as you would like. Or combine both acids together to level up your skincare routine. When in doubt, consult a licensed dermatologist.

Introduce glycolic acid and lactic acid to your routine

So, now you’re all caught up on the ins and outs of glycolic acid and lactic acid. In which case, there’s never been a better time to introduce either one (or both) to your routine.

Start with identifying your beauty concerns. Do you want to lessen the breakouts or tackle the age spots? Also, keep your skin type in mind when choosing your acid of choice.

Last but not least, gradually increase the acid concentration. This is to give your skin sufficient time to get used to it. Know which skincare ingredients go well with glycolic acid and lactic acid and which don’t. And never forget your sunscreen following a bout of chemical exfoliation.