Cosmetic acid: the right acids for the skin

We have known some of them for a long time. Others have recently appeared on the labels of our cosmetics. And for good reason, acids can give us beautiful skin. How do they act? What skin types are they aimed at? Do they have any contraindications? A specialist answers us.

Alpha Hydroxy Acids (AHA) for new skin

They are present in certain plants: apple (malic acid), citric (citrus), glycolic (sugar cane). They are used as keratolitics to remove dead cells at varying concentrations depending on the desired effect.

They reduce the visibility of spots by accelerating the exfoliation of the stratum corneum loaded with melanin. They stimulate “turn over” and this cellular renewal allows for better skin quality. If you have thin and sensitive skin, use them in the evening, choosing low concentrations and start, if necessary, by applying them every two or three days.

Beta Hydroxy Acids (BHA), anti gray complexion

Their main representative is salicylic acid, present in willow and in aspirin. They have the same functions, indications and precautions for use as AHAs.

Keto acids, for a gentle peel

These are organic acids found in certain flowers, such as hibiscus. They are an alternative to AHAs to be recommended if the skin is sensitive because they are less irritating.

18 Beta Glycyrretinic acid or Enoxolone, against spots

Present in licorice, it is a recognized anti-inflammatory. It also has interesting anti-stain properties. In subjects with atopic dermatitis it reduces redness, edema and itching.

More generally, it is an excellent protector and an effective local treatment which calms skin irritations.

Hyaluronic acid for hydrated and plumped skin

This universal moisturizer, formerly of animal origin, is now obtained by biotechnology. If hyaluronic acid is of high molecular weight, with large molecules it remains on the surface, and instantly smoothes my skin.

The most interesting are fractionated hyaluronic acids whose small molecules, by slipping between the cells, restore a plump and plump appearance to the face. This is a good plan if the skin tends to wrinkle and lose its softness.

Retinoic acid, anti-wrinkle and smoothing

This active derivative of vitamin A activates collagen synthesis and reduces fine lines. But be careful: it is very irritating and in any case is only available under medical prescription. It increases the photosensitivity of the skin and requires wearing effective sun protection at all times.

It is nevertheless possible to find Retinol (pure vitamin A) over the counter, part of which is naturally transformed into retinoic acid. But you shouldn't use it every night until the skin gets used to it. It may flake, tingle and redden during the first applications. If these side effects persist, you must stop the treatment for a few days.

Ascorbic acid or vitamin C, for radiant skin

It is present in many plants (acerola, strawberries, citrus fruits). It is the champion of anti-aging as its spectrum of activity is broad. It protects cells from oxidation, it boosts collagen, accelerates healing, and fights against spots.

Its fault: it is a very unstable molecule which cannot withstand water, light or heat. This is overcome by the use of stabilized vitamin C derivatives which have the same effectiveness. A word of advice: if the skin is hypersensitive, it is better to avoid formulas with acidic pH which can irritate. The dermatologist and pharmacist are there to advise me.

Folic acid, or Vitamin B9, to repair tired skin

It is found in green vegetables (spinach, salads, sorrel), animal livers, dried nuts. It has a restorative action on tired cells. Excellent for combating tight lines and without contraindication topically.

Azelaic acid, against excess sebum

Naturally present in certain cereals (wheat, barley), azelaic acid is an excellent anti-stain agent. It is particularly suitable if you have oily skin because, at the same time, it regulates and normalizes sebum.

Essential fatty acids or EFAs, for supple and nourished skin

These are omega-3 and omega-6 (linoleic, arachidonic acid) which are found in certain vegetable oils such as sunflower and rapeseed. They are not synthesized by the body and must therefore be provided through food or topically on the skin. They stimulate the metabolism of cells, contribute to good cohesion between them and provide the epidermis with beautiful elasticity. If you follow a low-fat diet, it is in your best interest to nourish your skin.

Thanks to Lionel de Benetti, cosmetologist engineer.

(File) Cosmetics: the best active ingredients for beautiful skin – 55 articles to consult