Mandelic Acid vs Lactic Acid

Mandelic Acid vs Lactic Acid

By Calum Torrington

26 September 2022

When looking to improve the appearance of your skin, the options out there can be truly daunting.

With the number of active ingredients promising younger, firmer, plumper, and more radiant skin- it’s hard to know where to start!

You might have noticed the active ingredients in many popular products often include the suffix ‘acid’.

If you’ve ever wondered why you should be putting acid on the delicate skin of your face, the simple answer is that acids lower the pH of your skin.

This dissolves those unwanted dead skin cells that cause all kinds of common issues we may experience.

Acids act like chemical exfoliators and are even used in skin peels. However, not all acids are the same, and they interact with the skin in very different ways.

With that very brief intro to acids, we are now going to break down two of the best that aid in giving the skin a smoother look: Mandelic acid and Lactic acid.

Their uses and benefits are practically identical, so unsurprisingly there is a lot of confusion surrounding what the differences actually are.

We’ll tell you all you need to know about each, as well as how to use them- and the best product recommendations!

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What is Mandelic Acid?

Mandelic acid is derived from bitter almonds and falls under the category of alpha hydroxy acid, or AHA.

These acids are water-soluble, and thought to improve the condition of the skin in a variety of ways.

Among AHAs, mandelic acid has a reputation for being more gentle on the skin.

This may be due to the fact that it is absorbed into the skin more slowly due to the size of the molecules, which are quite large.

This makes this active a good option for those with sensitive skin; however, keep in mind that irritation of the skin is still possible as with all acids.

People use mandelic acid for many of its benefits such as exfoliation, reduction of pigmentation and discoloration, treatment of acne-prone skin, and reduction of fine lines and wrinkles.

What is Lactic Acid?

Lactic acid is another type of AHA, one that is derived from the fermentation of lactose which is found in milk.

Like mandelic acid, it acts as a chemical exfoliant and is used for the same types of skin problems such as dark spots, aging, and acne.

At higher concentrations of more than 12%, lactic acid is able to penetrate into deeper layers of the skin. In this case, the skin can plump and firm, which helps to smooth it further.

However, lower concentrations such as 5% can also provide benefits by treating the surface layer of the skin.

Like mandelic acid, lactic acid is known for being one of the gentler AHAs and is commonly used in products for those with more sensitive skin.

Mandelic Acid vs Lactic Acid: What's the difference between the two?

These two actives are very similar (despite one being derived from willow bark and the other from lactose).

Both are AHAs, are used for the same benefits, and are gentler on the skin than their more aggressive counterparts. So what differentiates the two, and which should you try?

Well, even though both are known for their gentleness, when comparing the two, mandelic acid tends to still be the more gentle one.

So, if you have sensitive skin, that’s the one to go for! It’s also a good choice if you prefer ingredients that come from plants rather than animals.

The molecules of lactic acid are smaller than that of mandelic acid, so it is absorbed more rapidly by the skin.

Lactic acid contains sodium lactate- a salt- which means it will bind with water. This makes lactic acid more hydrating compared to mandelic acid, so if you have dry skin, maybe start with lactic acid and see how your skin reacts.

If you find it too harsh, you can always switch it out for mandelic acid.

Using both actives

As with most acids, using too much can be harmful to your skin.

For both of these ingredients, it is only recommended that you use them up to a maximum of three times per week.

These types of products should always be applied after washing your face with a mild cleanser and patting the skin dry.

As the products come in a variety of forms, you will need to follow the specific directions for that particular skincare product. You can then moisturize as normal after using it.

If skin sensitivity isn’t an issue for you, using both ingredients in your skincare routine is possible.

The golden rule is to apply the product with the thinner consistency first, followed by the thicker product.

However, you want to allow your skin to absorb the first ingredient before applying the next to reduce the risk of irritation.

Because layering products can be risky as overdoing it can lead to irritation, a safer option would be to alternate the days you use each product, or to find a product that contains both ingredients. This way, the concentrations are more likely to be balanced.

If you notice that your skin is burning, peeling, tingling, red, or feels waxy, then you’re most likely overdoing it.

Either scale back on the routine, go for only the gentlest option (in this case, mandelic acid) or stop treatment altogether and talk to your doctor about options better suited for your skin type.

Our Product Recommendations

Have you decided that mandelic acid is the treatment for you?

The Ordinary offers a serum with 10% mandelic acid that is combined with Tasmannia Lanceolata Fruit/Leaf Extract. Just apply a few drops to your freshly cleansed face and spread gently.

Does lactic acid sound like a better choice for your dry (or maybe sensitive) skin?

Good Genes boasts a lactic acid treatment that can plump out those fine lines and make skin more radiant in just three minutes.

It balances purified lactic acid with licorice, lemongrass, arnica, prickly pear extract, and aloe to help soothe, brighten, and moisturize the skin without greasiness.

Finally, is an effective blend of active ingredients what you’re after?

Pal’s Skin Lab has a 14% AHA resurfacing serum that contains multiple acids to make up a super exfoliating serum.

It blends a potent combo of AHA acids with aloe vera and licorice root extract to peel and smooth skin texture and tone.

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