Why Mandelic Acid Is The Acne-Fighting Ingredient Your Skin Needs

mandelic acid for acne

There’s a skincare acid that you should be including in your skincare routine if you want to reduce breakouts (and fade acne scars): mandelic acid.

Read on to discover everything you need to know about how mandelic acid works to fight acne and how you can incorporate this skincare acid into your routine.

What Is Mandelic Acid?

First of all – what is mandelic acid?

In chemical terms, mandelic acid is classified as an alpha-hydroxy acid (AHA), which are a group of water-soluble chemical compounds that have the ability to exfoliate dead skin cells from the uppermost layers of the skin.

Mandelic acid is derived from bitter almonds and it differs from other types of alpha-hydroxy acids because of its large molecular size – making it less irritating as it cannot penetrate as deeply into the skin as glycolic acid and lactic acid (which have much smaller molecular sizes).

Although mandelic acid isn’t as widely used in skincare products as other AHAs (and there isn’t as much research focusing on this skincare ingredient), it’s larger molecular size makes it a fitting choice for people with sensitive skin.

As well as being able to exfoliate dead skin cells, mandelic acid also has anti-fungal, anti-inflammatory, anti-bacterial and skin-brightening properties – all of which are beneficial for acne-prone skin.

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What Does Mandelic Acid Do For Acne?

Acne is caused by sebum (oil), bacteria and dead skin cells clogging pores in the skin, as well as inflammation.

Using skincare products containing mandelic acid can help reduce acne breakouts by:

  1. Removing dead skin cells that may otherwise clog pores and lead to acne
  2. Increasing cell-turnover, which reduces the appearance of acne
  3. Keeping acne-causing bacteria at bay due to its antibacterial properties
  4. Minimizing skin inflammation (since inflammation is required for acne to form)
  5. Dissolving sebum (oil) build-up within pores

In general, AHAs are water-soluble, meaning that they cannot actually penetrate pores to clear away oil build-up.

However, mandelic acid is actually more oil-soluble compared to other AHAs (such as glycolic acid) as it contains an aromatic ring in its chemical structure. This property allows it to enter pores and unclog the sebum trapped within them.

This study from 2015 investigated the effectiveness of a 30% mandelic acid peel on acne vulgaris in 15 patients. Improvements in acne lesions were noted in all patients in the study over a course of 6 peeling sessions (with an average improvement of 53%).

What Skin Type is Mandelic Acid Best Suited For?

So we just learned that mandelic acid is a great choice for those with oily and acne-prone skin. But, mandelic acid is actually suitable for all skin types.

Even people with sensitive skin and rosacea can benefit from mandelic acid as it is much more gentle on the skin compared to other AHAs. In fact, people who experience irritation with other AHAs, can use mandelic acid without any problems.

This is likely due to mandelic acid being a much larger molecule compared to other AHAs, which means that it penetrates the skin at a slower rate.

Mandelic acid is also suitable for those wanting to fade hyperpigmentation (such as melasma and dark spots) due to its ability to increase cell turnover rate.

This study found that the most common side effects during 6 treatments of a 30% mandelic acid peel was burning and erythema (redness), which completely subsided over a few hours. Some of the patients also experienced dryness of the skin, however the mandelic acid peels were well tolerated overall, and no patients developed post-inflammatory hyperpigmentation, flare up of acne, photosensitivity, scarring or allergic reactions.

Does Mandelic Acid Cause Purging?

Mandelic acid and other active ingredients (mainly chemical exfoliants and retinoids) that trigger skin cell turnover rate can cause skin purging, which appears as various types of inflammatory acne.

The reason that purging happens is because as your skin is exfoliated, acne formation is sped up. As new cells are brought to the surface, all the build-up underneath the surface of your skin comes to the surface too and forms a head.

In fact, purging doesn’t involve new pimples forming as a result of using a new skincare ingredient. Instead, these pimples were already there, but a purge just speeds up their formation.

I know that acne is the last thing you want to experience when you’re actually wanting to get rid of the breakouts you’re already dealing with. But, there is some good news though: the acne that occurs during a purge doesn’t last as long as a regular breakout and purges don’t go on forever.

Purges typically don’t last longer than 4-6 weeks (as this is how long it takes the pimples underneath your skin to come to the surface as your skin is exfoliated).

Does Mandelic Acid Help Acne Scars?

Yes, mandelic acid can help to fade the dark marks left by pimples, which are otherwise known as post-inflammatory hyperpigmentation.

This study found that a chemical peel consisting of 10% mandelic acid and 20% salicylic acid resulted in visible improvements to post-acne hyperpigmentation (six peeling sessions were conducted every fortnight over a 10 week period).

In fact, the improvements in post-acne hyperpigmentation were found to be better than those observed with 35% glycolic acid peels conducted over the same time period in another group of patients.

The ability to fade post-acne hyperpigmentation (as well as other types of hyperpigmentation) is believed to be the result of the increased cell turnover and exfoliating properties of mandelic acid.

The same study above also found that the same peel consisting of mandelic acid and salicylic acid led to a subtle decrease in the number of icepick and boxcar scars.

This study from 2013 suggests that mandelic acid stimulates the dermal fibroblasts in the skin to deposit more collagen, elastin and glycosaminoglycans (through a mechanism that is yet to be determined) – thereby decreasing the appearance of icepick and boxcar scars caused by acne.

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How Long Does It Take For Mandelic Acid To Work?

You’ll notice some initial improvements in the texture of your skin within a few days of introducing mandelic acid to your skincare routine (your skin will look smoother).

When using mandelic acid for acne, some people notice improvements to their skin within 1-2 weeks of using mandelic acid. However, it’s likely to take up to 4-6 weeks to see substantial improvements to your acne.

This is because it does take some time for mandelic acid to clear out all the congested material from inside your pores. Plugs that are already forming underneath the skin will take about 3-4 weeks to come to a head as whiteheads or cysts.

It is once the plugs underneath the surface of the skin are cleared (and new ones prevented from forming) that your skin will become noticeably clearer.

Mandelic Acid vs Salicylic Acid For Acne

Salicylic acid is one of the most well-known acne fighting ingredients.

Unlike mandelic acid, which is an alpha-hydroxy acid, salicylic acid is a beta-hydroxy acid (BHA). It is the only true BHA and is naturally found in the bark of willow trees (although it is produced synthetically for commercial products).

Salicylic acid actually works in a similar way to mandelic acid to treat acne: it has anti-inflammatory and anti-bacterial properties which help to treat pimples that have already formed. Just like mandelic acid, salicylic acid can unclog pores by breaking down the bonds between dead skin cells, oil and other gunk that can otherwise go on to cause breakouts.

However, the main difference between mandelic acid and salicylic acid is that salicylic acid is an oil-soluble compound, which means that it can penetrate much deeper into the pores.

So which one of these skincare acids works better at treating acne?

Research has found that salicylic acid and mandelic acid have almost equal efficacy in improving mild-to-moderate acne. However, salicylic acid appears to be better at treating non-inflammatory acne (whiteheads and blackheads), while mandelic acid appears to be better at treating inflammatory acne (papules, pustules, nodules, and cysts).

Inflammatory acne tends to more severe than non-inflammatory acne and it also more likely to cause acne scars (such as post-inflammatory hyperpigmentation and pitting), so your skin might benefit from mandelic acid more if you tend to have inflammatory acne.

Although both acids may be equally powerful at treating acne, mandelic acid is much gentler than salicylic acid (owing to it’s larger molecular size which allows it to penetrate the skin at a slower rate). If you have dry or sensitive skin, you may experience irritation while using salicylic acid (although some products are carefully formulated with hydrating and soothing ingredients).

mandelic acid vs salicylic acid for acne

Can You Use Salicylic Acid And Mandelic Acid Together?

You should be careful not to over-exfoliate your skin when using exfoliating acids, as doing so can damage your skin barrier and cause redness and irritation, dryness and flakiness, increased oil production and acne.

However, unless you have very sensitive skin, you should be able to use salicylic acid and mandelic acid together in your skincare routine – plus doing so has been found to be an effective way to treat acne.

This study found that a 20% salicylic–10% mandelic acid peel was not only safe, but more effective than a 35% glycolic acid peel in the treatment of both noninflammatory and inflammatory lesions of facial acne vulgaris. After a 20 week salicylic acid-mandelic acid treatment program, patients reported significant improvements in:

  • comedones
  • papules
  • pustules
  • total acne scores
  • post-acne hyperpigmentation
  • icepick scars, and
  • boxcar scars

In terms of side effects, the study above reported that the salicylic acid-mandelic acid peel was tolerable to all patients. 20% of the patients that received the salicylic acid-mandelic acid peel reported a burning or stinging sensation and 15% of patients reported skin dryness.

What Mandelic Acid Products Can I Use?

There are two main options for anyone wanting to incorporate mandelic acid into their skincare routine:

  1. Visit a dermatologist to receive treatments with a high-strength mandelic acid peel, or
  2. Buy an over-the-counter skincare product containing mandelic acid that you will be able to use at home

Over-the-counter skincare products (usually serums and exfoliating toners) contain a lower concentration of mandelic acid than peels and are therefore much gentler on your skin – meaning they can typically be used on a daily basis.

#1 Choice: By Wishtrend Mandelic Acid 5% Skin Prep Water

By Wishtrend 5% Skin Prep Water How To Use

Where to buy it: Yesstyle and Stylevana

Why I love it: This is a hydrating and gentle exfoliator that can be used daily. It is formulated with 5% mandelic acid, which means that even those with sensitive skin can benefit from this product.

Ingredients I love: Aside from mandelic acid, this exfoliator also contains beta-glucan (hydrating and anti-aging), panthenol (AKA vitamin B5 – hydrating), licorice root extract (soothing), sodium hyaluronate (hydrating), and Centella asiatica extract (soothing).

Full ingredients list: Water, Mandelic Acid, Butylene Glycol, Beta-Glucan, Panthenol, Glycyrrhiza Glabra (Licorice) Root Extract, Prunus Amygdalus Dulcis (Sweet Almond) Fruit Extract, Sodium Hyaluronate, Sorbitan Sesquioleate, Centella Asiatica Extract, Houttuynia Cordata Extract, Sorbitol, Dimethyl Sulfone, Chlorphenesin, Sodium Citrate, Arginine, PEG-60 Hydrogenated Castor Oil, Ethylhexylglycerin, Natto Gum, Carbomer

How to use it: After cleansing, apply an adequate amount to your skin (avoiding contact to your eyes) and pat lightly for better absorption. If your skin requires more exfoliation, you can soak the exfoliator into a cotton pad and wipe your skin gently. Follow with hydrating toner and the rest of your skincare routine.

By Wishtrend recommend using this product 3-4 times weekly to start off with (2-3 times weekly if you have sensitive skin).

Be sure to always wear SPF while using this product. Any type of exfoliating acid that results in an increase in cell turnover will make your face become more susceptible to ultraviolet (UV) radiation (even on days you don’t use them).

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How to store this product: By Wishtrend recommends that this product is stored in the fridge and that it should be used within 6 months of opening.