Acide glycolique : bienfaits pour la peau, effets secondaires et plus encore

What is glycolic acid?

If you’re looking to upgrade from a skincare amateur to a skincare pro, glycolic acid should be on your need-to-know list.

Glycolic acid is an alpha hydroxy acid (AHA), a natural acid derived from plants - in this case, sugar cane. It's made up of tiny molecules that can easily penetrate your skin barrier, helping to make it a particularly effective anti-ageing ingredient that promotes good skin health.

Benefits: what does glycolic acid do?

So why exactly is glycolic acid good for your skin?

Dr Susan Mayou, consultant dermatologist at the Cadogan Clinic explains that glycolic acid works by dissolving the intercellular glue which holds your skin cells together.

"This results in the exfoliation of those cells - helping to remove dead skin and clear pores," she says.

Unlike mechanical exfoliants, such as face scrubs, glycolic acid is a gentler way to exfoliate your skin. This chemical exfoliant doesn’t require harsh scrubbing and instead removes skin cells while retaining moisture.

Mayou adds: "This helps brighten the skin's appearance, as light reflects better off a smooth skin surface, giving a more youthful and more radiant appearance."

Glycolic acid can benefit everyone's skin but people with the following skin issues may find it particularly helpful.

How to use glycolic acid in your skincare routine

These far-reaching skincare benefits may have you ready to dive head-first into a tub of glycolic acid. However, it's important to get your skin used to the product. Mayou advises first-timers to start with a gentle cleanser that contains a glycolic acid concentration of no more than 2% if you wish to use it every day.

Glycolic acid products come in many forms

How often should you use glycolic acid?

Low to medium concentrations
Mayou cautions: "If using glycolic acid products containing 1-2% concentration, your skin should be able to tolerate this ingredient daily. However, it's important to build up gradually to avoid intolerance and sensitivity."

Beginners may wish to start by applying glycolic acid just three times per week for the first one or two weeks. If your skin doesn’t feel irritated, you can increase to four times per week for the same period. Continue gradually building up the frequency until it is used as part of your daily skincare routine.

Medium to high concentrations
Mayou says: "Products containing 10% and more should only be used once or twice a week as they are harsher and may cause a reaction. Remember, the higher the concentration the greater the peeling action."

If you have a generous skincare budget, professional glycolic acid peels contain the highest concentration and are a good option if you're looking to treat a specific skin issue. However, this means they carry a greater chance of irritation. You should aim to leave at least two weeks in between peels.

You can also purchase at-home glycolic acid peels. These tend to be more affordable and contain lower concentrations. Always read the label and don't exceed the recommended frequency of use.

Side effects and risks

Irritation

So why do you need to be mindful of how much glycolic acid you use? In short, using too much can upset your skin. For some skin types, even small amounts can lead to side effects.

If you notice any of these symptoms, stop using your product. If you wish to try again, give your skin a chance to recover fully, and then choose a smaller concentration and limit how often you apply it.

Sun damage

While glycolic acid offers great anti-ageing benefits, it can leave you more vulnerable to harmful UV rays. One study found that glycolic acid led to DNA damage, sunburn, and erythema - a skin rash caused by inflamed blood vessels - in participants, whereas, another exfoliating and anti-inflammatory skin treatment did not.

When glycolic acid removes the top layer of dead skin cells, it exposes the cells underneath, leaving them more sensitive to sun damage. Therefore, Mayou advises wearing a sunscreen with sun protection factor (SPF) 50+ every day before going outside. You will need to do this for as long as you use glycolic acid and for one week afterwards.

Can you use glycolic acid when pregnant?

Glycolic acid is safe to use in la grossesse et l'allaitement. However, Mayou advises you use a low concentration and remember to apply SPF.

Pour en savoir plus

1. Campos, Pitassi, Gonçalves, Sant'Annhttps://pubmed.ncbi.nlm.nih.gov/33617668/am, and Correia "Clinical evaluation of the efficacy of a facial serum containing dioic acid, glycolic acid, salicylic acid, LHA, citric acid, and HEPES in treating post-inflammatory hyperchromia and controlling oily skin in patients with acne vulgaris".

2. Kornhauser, Wei, Yamaguchi, Coelho, Kaidbey, Barton, Takahashi, Beer, Miller, and Hearing "The effects of topically applied glycolic acid and salicylic acid on ultraviolet radiation-induced erythema, DNA damage and sunburn cell formation in human skin".