Glycolic Acid: Origins, Benefits, Properties, and Uses

A versatile, naturally derived active ingredient

Glycolic acid (INCI: Glycolic Acid) belongs to the family of alpha-hydroxy acids (A.H.A.). This active ingredient is mainly derived from plant extracts such as sugar cane, beetroot and grapes. Thanks to its particularly low molecular weight, it is absorbed exceptionally well into the upper layers of the epidermis, thereby optimising its effectiveness on the skin.

How does it work on the skin?

The action of glycolic acid on the skin is based on several key biological mechanisms:

1. Exfoliation and regeneration of the epidermis: By gently removing dead cells that have accumulated on the surface of the epidermis, it stimulates cell renewal. Regenerated skin is visibly smoother, the skin texture is refined and irregularities in pigmentation or texture are reduced

2. Optimised hydration: Application of this active ingredient leads to a significant increase in hyaluronic acid and glycosaminoglycan levels, in both the epidermis and the dermis

3. Improved skin thickness: These various processes of extracellular matrix remodelling lead to a measurable increase in skin thickness.

What are the different types of AHAs?

AHAs, or fruit acids, are natural organic acids that are essential for radiant skin. Each has unique properties that enable them to target specific skin needs:

Glycolic acid has established itself as a key active ingredient for addressing skin concerns such as uneven texture, dullness or signs of ageing. Thanks to its targeted exfoliating action, it helps to precisely address several major skin concerns:

• Dull complexion and lack of radiance: By gently removing dead skin cells accumulated on the surface of the epidermis, this active ingredient reveals the face’s natural radiance. The skin appears fresher, the complexion is evened out and signs of skin fatigue are visibly reduced [4]

• Blemishes, enlarged pores and skin marks: By promoting the removal of dead skin cells, it helps to unblock clogged pores and refine the skin’s texture. This gentle exfoliating effect helps to fade residual skin marks, thereby improving the visual evenness of the skin [4]

• Signs of ageing, fine lines and loss of firmness: Glycolic acid helps to stimulate collagen production and may also promote improved quality of elastic fibres and an increase in hyaluronic acid levels in the epidermis and dermis. These processes help to firm the skin and reduce the appearance of fine lines [1, 2, 3]

• Pigment spots and uneven skin tone: By accelerating cell renewal in the epidermis, it helps to regulate pigmentation contrasts. Regular application therefore helps to gradually reduce brown spots caused by sun exposure or skin ageing. [3, 4]

Serums generally contain a higher concentration of glycolic acid and are therefore more effective at tackling specific skin problems such as acne scars or hyperpigmentation. Thanks to its exfoliating effect, this serum removes dead skin cells and stimulates skin renewal for a radiant, even complexion. Particularly suitable for skin affected by sun damage, smoking or premature ageing, it reduces acne scars and smooths out uneven texture. It also tightens the skin’s pores, combats blackheads and reduces wrinkles and dark spots. Apply the serum after cleansing and toning your skin, then allow it to absorb before applying your moisturising night cream.

Discover our 10% Glycolic Acid & AHA Serum

Glycolic acid is suitable for many different skin types. The table below outlines its beneficial effects according to the specific needs of each skin type: 

Glycolic acid is best used in the evening, on clean and completely dry skin. To reap its benefits whilst minimising the risk of irritation, it is important to follow a few simple steps and allow your skin time to adapt gradually: 

1. Thoroughly remove any make-up: if you are wearing make-up or sun cream, start by removing these to prevent impurities from reducing the product’s effectiveness.

2. Gently cleanse your face: then use a gentle cleanser suited to your skin type to remove any remaining residue without compromising the skin’s barrier.

3. Dry your skin thoroughly: wait until your face is completely dry before applying the product. Damp skin can increase the absorption of glycolic acid and exacerbate feelings of discomfort or tightness in sensitive skin.

4. Apply glycolic acid in the evening: A small amount is sufficient. A few drops or a thin layer of the product will do. Spread it evenly over your face, avoiding the eye area and any irritated areas.

5. Moisturise your skin after application: Applying a moisturiser after using glycolic acid helps to maintain skin comfort and support the skin’s natural barrier following exfoliation.

6. Apply sun protection the following day: even when used the night before, glycolic acid makes the skin more sensitive to external aggressors. Sun protection is therefore essential during the day, the day after application.

7. Start gently: limit yourself to 2 to 3 applications a week to begin with, whilst your skin gets used to it.

Glycolic acid should be introduced into your skincare routine gradually and carefully. This powerful active ingredient requires a period of adjustment to allow the skin to get used to its exfoliating action without causing any discomfort.

For a gentle introduction (first use)

When introducing this active ingredient for the very first time, it is recommended to start with very infrequent applications, at a rate of once or twice a week for the first two weeks. This cautious approach allows you to assess your skin’s tolerance and prevent any temporary tingling or slight redness. If the skin shows excellent tolerance, it is then possible to increase the frequency very gradually.

For blemish-prone skin

To effectively target blocked pores and help smooth out superficial skin imperfections, regularity is essential. Once the introductory phase has been successfully completed, application can be considered every two to three days, preferably in the evening. 

For mature skin or skin lacking radiance

To support the skin’s natural cell renewal process and visibly reduce the appearance of fine lines, a frequency of two to three applications per week is generally ideal. For more concentrated exfoliating treatments, such as superficial peels to be carried out at home, applications should be spaced further apart – ideally every two to five weeks as part of a course of treatment – in order to allow the skin’s natural regeneration cycle to take place.

Immediate effects

From the very first applications of a skincare product containing glycolic acid, the skin’s texture begins to change visibly. By removing dead skin cells that have built up on the surface of the epidermis, this active ingredient reveals smoother, softer skin and a radiant complexion. Although the initial effects of superficial exfoliation are subtle, they gradually intensify with regular use. This is the ultimate ‘instant radiance’ effect, ideal for temporarily evening out skin texture and revitalising a tired complexion.

Long-term results

Regular use over several months leads to a genuine remodelling of the extracellular matrix in both the epidermis and dermis. The benefits become firmly established over the long term:

• Skin densification: Continuous use for six months promotes a measurable thickening of the skin. Indeed, in a study involving a 25 per cent AHA lotion applied for approximately six months, an increase of around 25 per cent in skin thickness was observed. [2]

• Firmness and elasticity: This active ingredient stimulates collagen production and hyaluronic acid synthesis. Collagen density and the quality of elastic fibres are improved, helping to visibly reduce fine lines [3]

• Overall harmonisation: By accelerating cell renewal, glycolic acid provides long-lasting smoothing of the skin’s texture, reduces the appearance of skin imperfections and evens out pigmentation.

The best combinations to use with glycolic acid

To complete your skincare routine alongside glycolic acid, do take a look at our favourite skincare products:

Plum & Oat Cleansing Oil

This make-up remover oil effectively removes make-up, even waterproof varieties, as well as excess sebum and impurities that have built up throughout the day. Its gentle, comfortable texture transforms into a milk upon contact with water, making it easy to rinse off whilst leaving the skin supple and free from tightness. Its minimalist, fragrance-free formula is suitable for all skin types and is an ideal way to gently remove make-up before using an active ingredient such as glycolic acid. To use, dispense 1 to 2 pumps into the palms of your hands and warm the product slightly. Then massage onto dry skin (face, lips and eyes) using gentle circular movements. Add a little water to emulsify the oil, which will turn into a milk, then rinse thoroughly with clean water. Please note that this product is for external use only. In case of contact with the eyes, rinse immediately with clean water.

Discover the Plum & Oat Cleansing Oil

Gentle Prebiotic, Zinc & Cucumber Cleansing Gel

This facial cleansing gel gently purifies the skin whilst removing impurities and make-up residue, whilst respecting the skin’s pH balance, making it ideal as part of a skincare routine involving the use of an AHA. Its naturally derived formula, enriched with organic cucumber, inulin and zinc PCA, helps to soothe the skin. It is suitable for all skin types, including sensitive skin, and leaves no tightness after rinsing. Simply apply to damp skin on the face and neck after using your make-up remover oil, work into a light lather by massaging gently, then rinse thoroughly with clean water. Take care to avoid contact with the eyes. In case of contact, rinse immediately and thoroughly with clean water.

Discover the gentle Prebiotic, Zinc & Cucumber Cleansing Gel

10% Glycolic Acid & AHA Concentrated Serum

This is the stage at which you apply your glycolic acid treatment. This exfoliating serum helps to remove dead skin cells, stimulate cell renewal and visibly improve the radiance of your complexion. It also targets uneven skin texture, enlarged pores, blackheads, as well as pigmentation marks and spots, for smoother, more even-toned skin. Its light, non-greasy and fragrance-free gel texture is enriched with hyaluronic acid to maintain the skin’s moisture levels. Apply in the evening only, to clean and completely dry skin, after cleansing. Dispense a few drops onto the face, then spread evenly, avoiding the eye area. Allow it to absorb before applying your moisturiser. Warning: if irritation occurs, discontinue use. Keep out of reach of children and avoid the eye area.

Discover the 10% Glycolic Acid & AHA Concentrated Serum

All-purpose cream

This multi-purpose cream intensely nourishes the skin whilst providing comfort and suppleness. Its certified organic formula, enriched with aloe vera, jojoba oil, calendula and cocoa butter, helps to support the skin’s barrier and keep the skin soft and soothed, which is beneficial after using an AHA. Its melt-in-the-skin yet non-greasy texture makes it a pleasure to use on the face, particularly in the evening after applying active ingredients. After applying your glycolic acid, apply the cream to clean, dry skin. Massage gently until absorbed, paying particular attention to areas that feel tight or are sensitive. 

Discover the all-purpose cream

Organic Mineral Sunscreen Stick SPF 50

This certified organic sun stick offers high SPF 50 protection against UVA and UVB rays, and is particularly suitable for sensitive areas of the face. Its 100% natural, vegan and water-resistant formula combines zinc oxide and pongamol to effectively protect the skin, whilst helping to prevent skin ageing thanks to organic passion fruit oil. It is recommended that you always use effective sun protection the day after applying AHA active ingredients, as these can make the skin more sensitive to external aggressors. Therefore, ensure you apply it every morning following your skincare routine containing glycolic acid. Apply the stick evenly to the areas requiring protection (nose, cheekbones, forehead, ears, lips, etc.). Reapply every two hours during prolonged exposure, as well as after swimming or sweating. Please note: always avoid exposure to the sun during the hottest hours of the day (12 noon–4 pm).

Discover our SPF 50 mineral sun stick

Combinations to avoid with glycolic acid

As the 10% Glycolic Acid & AHA Concentrated Face Serum, is highly concentrated in very potent active ingredients, it is advisable to avoid using it in combination with other serums. However, it is perfectly possible to use them at different times of the day: for example, apply the Hyaluronic Acid Serum in the morning, and use the 10% Glycolic Acid & AHA Serum in the evening.

Avoid combining AHA-based exfoliating treatments with other overly abrasive exfoliating or purifying products, such as certain cleansing powders or exfoliating cleansers. Combining several keratolytic active ingredients can weaken the skin barrier and increase the risk of irritation, redness or sensitivity. Instead, opt for a gentle cleanser on days when you use AHA, to maintain the skin’s balance and comfort.

Glycolic acid is a powerful exfoliating active ingredient that works by refining the skin’s outermost layer. This mechanism can temporarily make the epidermis more reactive to external aggressors, particularly UV rays, although it is not phototoxic. Consequently, after application, the skin may become more sensitive and prone to redness or a stinging sensation, especially if used too frequently or on a compromised skin barrier. It is therefore best to introduce it gradually and avoid sensitive areas such as the eye contour, which is particularly reactive to the addition of active ingredients that are too potent or introduced too quickly. As a precaution, it is recommended that you carry out a patch test on the inside of your elbow at least 48 hours before using the glycolic acid serum for the first time, to ensure there is no skin irritation. Even when applied in the evening, it is essential to use sun protection the following day to protect skin that has been sensitised by exfoliation. Finally, for very sensitive or reactive skin, it is best to space out applications and allow the skin to build up a tolerance gradually, rather than using the product intensively from the outset. 

When you start using an active ingredient such as glycolic acid, it’s easy to fall into the habit of wanting to use it every evening. In reality, your skin responds best when it has time to adapt gradually. Alternate with proper ‘off’ evenings where you simply let your skin rest, without any acids or exfoliation. On these evenings, a simple moisturiser is more than enough to support the skin barrier and maintain the skin’s balance. You can then gradually increase how often you use glycolic acid, whilst paying close attention to how your skin reacts.

Charlie holds a Master’s degree in cosmetic formulation. Passionate about cosmetology and a lover of words, she decided in 2020 to become a web editor specialising in cosmetics and beauty. Her desire for a career change inspired her to go freelance, giving her the freedom to work from anywhere in the world.