New: A treatment designed for rosacea-prone skin

New: A treatment designed for rosacea-prone skin

By edit
Face care
By concern
Stage of skin aging
Body care
Skin diagnostic
All Topics
Les PHA contre les marques brunes laissées par l'acné.

How To Reduce of Post-Acne Hyperpigmentation With PHAs.

PHAs (polyhydroxy acids) are part of the family of hydroxy acids along with AHAs (alpha-hydroxy acids) and BHAs (beta-hydroxy acids). Considered the new generation of AHAs, they are known for their keratolytic effects, i.e., they eliminate dead cells (desquamation process), which increases cell renewal and restores the skin's radiance. How do they work on acne marks?

Why Does Post-Inflammatory Hyperpigmentation Appear After Acne Outbreaks?

Even after the blemish is gone, acne can leave marks on the skin, called post-inflammatory hyperpigmentation. These persistent flat brown or dark spots are generated as a result of increased melanin production in response to an inflammatory reaction. Indeed, the appearance of these darker areas on the skin is based on the production of inflammatory cytokines, with pro-pigmentation properties, by the surrounding cells. These cytokines activate the melanocytes (melanin-producing cells), leading to a significant release of melanosomes (pigment granules) and thus to a surplus of melanin. Although this phenomenon can affect all skin types, it is generally more frequent in people with mixed to dark skin (phototypes IV to VI). 

Unlike the scars, these post-acne marks are temporary and usually disappear spontaneously without leaving scars after several months (between 3 and 24 months). Sometimes it takes several years. However, the speed of their disappearance depends on your relationship with the sun, which can lengthen the healing time, but also on the difference in skin tone between the color of the skin and the shade of the spot.

PHAs To Reduce the Appearance of Post-Acne Marks.

PHAs are keratolytic agents suitable for all skin types, even sensitive ones, unlike AHAs and BHAs. Indeed, because of their high molecular weight, they remain on the surface of the epidermis. This explains their good skin tolerance compared to other acids, which penetrate deeper into the epidermis.

There are many PHAs, here are two particularly common in cosmetic formulas:

  • Gluconolactone: This is a PHA naturally present in skin cells. This antioxidant effectively fights free radicals.

  • Lactobionic acid: This is a lactose derivative that has a moisturizing and soothing effect.

To fade post-acne hyperpigmentation, these peeling agents act by destroying the links between the most superficial cells of the skin to reorganize the epidermis. They accelerate desquamation and induce the rapid dispersion of melanin grains within the keratinocytes.

In other words, the application of PHA triggers a controlled desquamation of the epidermis, and with it the melanocytes and the marks left by the pimples.

Thus, cosmetic treatments based on acids (AHA, BHA and PHA) in low concentrations (up to 20%) can be used to reduce the appearance of post-inflammatory hyperpigmentation marks. However, several applications on a regular basis will be necessary to obtain visible results. In this sense, you can use our anti-mark serum. It specifically targets acne marks and is applied locally. It contains the gluconolactone presented above and Centella asiatica extract, an active ingredient known to help remodel the relief of marked skin.

How To Avoid Getting Post-Acne Hyperpigmentation?

In order to prevent the appearance of post-acne marks, it is important to avoid inflammation. To do so, we recommend that you consult a dermatologist to treat your acne as soon as possible with an appropriate follow-up. Also remember to moisturize your skin with a suitable face cream. This will promote healing. In addition, in order not to increase the inflammation and spread the infection, avoid popping or scratching your pimples. Finally, the sun reinforces the marks, thus lengthening the time needed for them to fade. Therefore, make sure to protect yourself on a daily basis with the application of a broad spectrum SPF sunscreen and also limit your exposure to the sun.


  • VAN SCOTT E. J. & al. Clinical and cosmeceutical uses of hydroxyacids. Clinics in Dermatology (2009).

  • PLATSIDAKI E. & al. Chemical peels in active acne and acne scars. Clinics in Dermatology (2017).


Understand your skin
and its complex needs.

Go further: