When should mandelic acid be used?

What is Mandelic Acid?

Mandelic Acid (INCI name: Mandelic Acid) is the largest of the AHAs (alpha-hydroxy acids), derived from the hydrolysis of bitter almonds. It is very gentle and non-irritating, and due to its high molecular weight, it penetrates less deeply into the epidermis than other AHAs, acting on the surface. This fruit acid, known for its keratolytic action, gently removes dead cells accumulated on the surface of the epidermis that dull the complexion, give an irregular appearance to the skin texture and are responsible for the appearance of blemishes.

The benefits of mandelic acid on the skin.

• Anti-blemish: Anti-microbial and anti-inflammatory, the use of mandelic acid skincare helps to control bacterial proliferation, unclog pores, and reduce inflammation. This, in turn, helps to smooth out irregularities and prevent future skin breakouts.

• Combating the signs of ageing: Regenerative in nature, mandelic acid promotes cellular renewal, which helps to address the signs of ageing, particularly by reducing the appearance of fine lines and improving skin elasticity.

• Radiance and complexion uniformity: with its exfoliating power, mandelic acid evens out the complexion, helps to restore radiance to the epidermis and reduces the appearance of pigmentation spots.

Photosensitising, potentially irritating, redness... the use of mandelic acid must be reasonable and controlled, even though it is considered mild and suitable for most skin types.

At what time of the day should mandelic acid be used?

Skincare products containing mandelic acid should be applied only in the evening to maximise effects and minimise the risks of irritation and photosensitisation. Indeed, AHAs, including mandelic acid, increase photosensitivity as they reduce the natural photoprotection provided by the stratum corneum, thereby promoting sunburn. It is therefore safer to apply skincare products containing AHAs at bedtime.

Furthermore, the night corresponds to the time when the skin initiates its natural regeneration process: this is when it will be most receptive to exfoliation and to the stimulation of cellular renewal induced by mandelic acid.

Nevertheless, cleansing treatments with a low concentration of mandelic acid (< 5%) can also be used in the morning. Additionally, the surfactants present in the product will eliminate the mandelic acid molecules.

In all instances, it is crucial not to forget to adequately protect oneself against UV rays by applying a product with a sun protection factor (SPF) at the end of one's morning routine.

How often should mandelic acid be used?

The frequency of use for a mandelic acid skincare product depends on the concentration of free acids. At a moderate concentration (> 8%), mandelic acid can be tolerated for a bi-weekly application. However, at a lower concentration (< 8%), it can be used daily, depending on your skin's tolerance level.

In all instances, it is advisable to start a skincare routine with mandelic acid progressively. Serum, lotion, night cream..., for treatments intended for daily use, start by applying them once or twice a week to acclimatise your skin.

Furthermore, treatments with a high concentration of mandelic acid are generally recommended for use in a course of several weeks or months until the desired results are achieved. It is possible to resume its use several months or years later if you wish.

For the initial use of a new mandelic acid skincare product, read and follow the manufacturer's instructions to ensure safe use and minimise the risk of irritation.