The benefits of AHAs for your skin are extraordinary, especially if you are looking to visibly improve your skin appearance. These alpha-hydroxy acids have become essential in our beauty routines, and it's not without reason.
Found naturally in fruits like grapes and lemon, AHAs or fruit acids offer remarkable benefits for the skin. Thanks to their exfoliating properties, they effectively eliminate dead cells and considerably improve skin texture. In addition, these active ingredients stimulate cell renewal and skin regeneration, particularly beneficial when our natural ability to renew cells slows down with age. This is also why AHAs are widely used in anti-aging care protocols.
Glycolic acid, in particular, helped popularize AHA treatments after being the subject of in-depth studies throughout the 20th century. Unlike BHAs, which work both on the upper part of the skin and inside the pores, AHAs work primarily on the surface to smooth the skin and reduce the appearance of fine lines and wrinkles.
In this comprehensive guide, we will explore together all aspects of AHAs: their origin, how they work, the different types available and how to effectively integrate them into your daily beauty routine to transform your skin.
Understanding AHAs: origin and functioning
AHAs are the talk of the beauty world, but what exactly are they and how do they work? Let's discover together these fascinating active ingredients that transform our skin.
What is an AHA?
AHAs, or alpha hydroxy acids, are carboxylic acids that have a hydroxyl group on the carbon located immediately after that of the carboxylic acid group. In simpler terms, it is a family of natural acids with a specific molecular structure that gives them remarkable exfoliating properties.
Among the best-known AHAs, we find:
- Glycolic acid (extracted from sugar cane)
- Lactic acid (from milk or fruits like tomatoes)
- Mandelic acid (derived from bitter almonds)
- Citric acid (from citrus fruits)
- Malic acid (found in apples and grapes)
These acids are often called "fruit acids" because they are found naturally in various fruits and plants. Glycolic acid and lactic acid are particularly prized in cosmetics for their exceptional ability to penetrate the skin.
Where do AHAs come from?
AHAs are of natural origin, although some can be reproduced synthetically for cosmetic use. They mainly come from sugars from fruits, plants or fermented milk.
Besides, the use of AHAs is not new! Cleopatra, known for her milk baths, already benefited from the virtues of lactic acid, long before the rest of humanity. This queen of Egypt intuitively understood the benefits of these acids on the beauty of the skin.
How do they act on the skin?
The mechanism of action of AHA is particularly effective. First, they work by exfoliating the upper layer of the epidermis, where the dead cells are found that give the skin an uneven appearance. Concretely, AHAs break down the intercellular “glue” that holds dead cells together.
Consequently, this action accelerates cell renewal by weakening the cohesion of the lower cells of the epidermis. This process, called desquamation, promotes the emergence of new cells on the surface.
In addition, AHAs have a hydrating action thanks to their ability to absorb water. They also stimulate intercellular communication as well as the production of collagen, which explains their effectiveness against the signs of skin aging.
Thus, AHAs function as a chemical exfoliant (as opposed to mechanical grain exfoliants) that gently renews the skin's surface, providing an immediate glow.
The different types of AHA and their specificities
Each type of AHA has unique characteristics that make it particularly effective for certain skin problems. Let's discover together these acids and their specific properties to choose the one that best suits your skin.
Glycolic acid: deep exfoliation
Glycolic acid is distinguished by its very small molecule, which allows it to penetrate deep into the skin. Extracted from sugar cane, it is considered the most powerful and versatile AHA. Its exfoliating action is remarkable for improving skin texture and reducing fine lines. Particularly effective against hyperpigmentation, it is also the champion for stimulating the production of collagen and elastin. However, its potency can cause irritation on sensitive skin.
Lactic acid: softness and hydration
Coming from fermented milk, lactic acid offers a perfect balance between effectiveness and gentleness. Less irritating than glycolic acid, it intensely hydrates the skin while exfoliating it. Moreover, its ability to retain water in the epidermis makes it a valuable ally against skin dryness. It is particularly recommended for mature skin that needs hydration and radiance without aggression.
Mandelic acid: ideal for sensitive skin
Derived from bitter almonds, mandelic acid has the largest molecule among AHAs, which slows its penetration and makes it particularly suitable for sensitive or reactive skin. Additionally, its natural antibacterial properties make it a great choice for treating acne and blemish issues. It is also effective against pigment spots without irritating skin prone to inflammation.
Citric acid: radiance and uniformity of complexion
Found in citrus fruits, citric acid is a powerful antioxidant that protects the skin against free radicals. It is therefore excellent for lightening the complexion and evening out pigmentation. Less exfoliating than its cousins, it is generally used in combination with other AHAs to potentiate their effects or to adjust the pH of cosmetic formulations.
Malic acid: stimulation of collagen
Extracted from apples and grapes, malic acid is known for its ability to stimulate collagen production. Furthermore, it helps maintain skin hydration while providing gentle exfoliation. Less irritating than glycolic acid, it represents an interesting alternative for skin that does not tolerate more aggressive AHAs.
The benefits of AHAs for the skin
Regular application of AHAs provides a multitude of skin benefits that go far beyond simple exfoliation. These fruit acids act at different levels to completely transform the appearance and health of your epidermis.
Elimination of dead cells
Above all, AHAs are powerful chemical exfoliants that dissolve the bonds holding dead cells to the surface of the skin. Unlike mechanical (grain) exfoliants, they provide gentle and uniform exfoliation. This keratolytic process promotes the elimination of surface impurities and naturally accelerates cell renewal. In fact, these acids trigger controlled desquamation for a real “new skin” effect.
Improved complexion radiance
Thanks to their exfoliating action, AHAs eliminate dead cells responsible for a dull complexion. This elimination gives an immediate boost of radiance and provides an instant healthy glow effect. Moreover, the skin becomes visibly brighter from the first applications, as evidenced by 90% of patients who report having softer skin after use. As a result, the complexion appears fresh and radiant, especially when waking up after nightly application.
Reduction of fine lines and wrinkles
AHAs significantly contribute to reducing the signs of skin aging. By stimulating the synthesis of collagen and elastin in the dermis, they improve the appearance of fine lines and wrinkles. In particular, malic acid is known for its ability to stimulate collagen production. Thus, the skin gains tone and facial features appear younger.
Hydration and elasticity
Contrary to popular belief, AHAs don't just exfoliate. They also have hygroscopic properties which allow them to attract and retain water in the epidermis. Glycolic acid, in particular, has proven beneficial effects on hydration. As for lactic acid, it is naturally present in the skin's natural hydration factor, which enhances its hydrating benefits.
Treatment of blemishes and clogged pores
AHAs are also effective in treating various skin problems. They limit sebum retention and prevent the appearance of microcysts, while unclogging pores. Glycolic acid, through its action on keratin, specifically helps eliminate blackheads. The results are impressive: up to 40% reduction in spots after 3 days of use, which explains why 78% of users notice smoother and refined skin.
How to incorporate AHAs into your beauty routine
Using AHAs requires a methodical approach to maximize their benefits while minimizing the risk of irritation. Here's how to effectively integrate these acids into your beauty routine.
Choosing the right AHA according to your skin type
The choice of AHA essentially depends on your skin type. For sensitive or reactive skin, lactic acid provides gentle exfoliation without causing major irritation, while maintaining good hydration. Very dry skin will also benefit from lactic or mandelic acid, both known for their hydrating properties. On the other hand, for oily, acne-prone skin, glycolic acid in a higher concentration will be more effective in regulating sebum and unclogging pores. Mature skin will find citric acid an ally against the signs of aging.
Recommended frequency of use
To get started with AHAs, start with weekly application then gradually increase according to your skin's tolerance. Ideally, limit yourself to 2-3 uses per week to avoid irritation. Concentration also plays a crucial role: beginners should favor low-concentration formulas (around 5%). For products with a high concentration, one or two weekly applications are sufficient, while those with a low concentration can be used daily.
Order of application with other treatments
Apply your AHA products to clean, dry skin. In your routine, follow this order: cleanser, toner, AHA exfoliant, then serums and targeted treatments. This sequence optimizes the penetration of active ingredients because, once the skin is free of dead cells, its absorption capacity is increased. Additionally, avoid using products containing AHAs and retinol at the same time - instead alternate their use.
Importance of hydration after use
Despite their slight hydrating properties, AHAs are primarily exfoliants. Therefore, it is essential to apply a moisturizer after use to compensate for potential dryness and strengthen the skin barrier. Formulas enriched with hyaluronic acid are particularly recommended.
Essential sun protection
AHAs thin the stratum corneum, making the skin more vulnerable to UV rays. Therefore, applying a minimum SPF 30 sunscreen every morning becomes imperative. Prefer to use your AHA treatments in the evening, not only to avoid sun exposure but also because cell renewal is more effective during sleep.
Conclusion
AHAs therefore represent much more than just a passing beauty trend. These natural acids truly transform the skin on many levels. First, their exfoliating power effectively eliminates dead cells, revealing more luminous and uniform skin. Then, their stimulating action on collagen production helps fight the visible signs of aging. Unlike mechanical exfoliants, AHAs offer gentle and even exfoliation that respects the skin's balance.
Each type of AHA has its own strengths. Glycolic acid, for example, penetrates deeply for intense action, while lactic acid favors hydration. Mandelic acid is perfect for sensitive skin thanks to its larger molecule. These differences allow everyone to find the acid suited to their skin type and specific concerns.
However, their use requires some essential precautions. Sun protection becomes essential, as does enhanced hydration after application. You should also start gradually, respecting the recommended frequency depending on your skin sensitivity.
Ultimately, AHAs are a wise investment for your skin. They act simultaneously on several issues: lack of shine, signs of age, imperfections or texture irregularities. This versatility explains why they remain essential in modern beauty routines. Adopt them with method, patience and regularity, and your skin will thank you with its visible and lasting metamorphosis.
