Les ingrédients cosmétiques à fuir pour éviter les rougeurs d'hypersensibilité.

Cosmetic ingredients to avoid to prevent hypersensitivity redness.

Some compounds found in skin or hair care products are recognized allergens. Exposure to these molecules can lead to hypersensitivity redness or even contact eczema, even in the absence of a genetic atopic predisposition.

Summary
Published August 11, 2022, updated on February 21, 2024, by Maylis, Chemical Engineer — 9 min read

Glycolic Acid.

Often used in chemical peels, glycolic acid is a fruit acid known for its exfoliating properties. Indeed, it has the ability to shed dead skin cells on the surface, thereby stimulating the renewal of the epidermal cells. Glycolic acid is present in many cosmetic product formulas at a concentration between 4 and 10%: serum, cream, tonic lotion, shower gel, etc... However, although it is suitable for almost all skin types (normal, combination to oily, and mature), glycolic acid can sometimes be poorly tolerated. The effects of this active ingredient vary greatly and depend on the concentration of glycolic acid, the pH of the product, and the application time. That's why it's important to always thoroughly read the instructions before any application.

Thus, it is likely and normal to experience slight tingling and a mild warming sensation, and to see redness appear following the application of cosmetics containing glycolic acid. However, depending on your skin's tolerance level, these symptoms may intensify and may even be accompanied by erythema, burning sensations, tightness, itching, and facial swelling, and hyperpigmentation. In rare cases, hypopigmentation, persistent erythema, and acne flare-ups have been reported. As soon as such side effects appear, immediately stop using the product and consider rinsing your face thoroughly with water. However, at Typology, we advise against its use onsensitive and reactive skin, as well as for individuals suffering from an inflammatory skin condition (eczema, rosacea, herpes, etc…). It is also advisable to avoid using it in pregnant women. Indeed, it is the cause of vascular disorders related to hormonal impregnation, resulting in congestive flare-ups on the face: the skin reddens more easily and becomes more sensitive.

Retinol.

Retinol belongs to the family of retinoids, which are derivatives of vitamin A, such as retinoic acid and retinal. Retinol is permitted at a concentration of 0.3% in a non-rinse cosmetic product. In practical terms, this active ingredient exfoliates the surface of the epidermis and removes dead cells. It also stimulates cell renewal and regulates the activity of melanocytes responsible for hyperpigmentation. Moreover, it boosts the production of collagen and elastin. No wonder it's recommended for smoothing skin texture and plumping wrinkles!

The most common adverse effect following the use of a retinol-based skincare product is an irritated skin characterized by the onset of redness, itching, and even mild burns. This is why this active ingredient is not recommended for sensitive and/or atopic skin. However, it is important to note that retinol requires a period of skin adaptation; if mild, tolerable redness appears, it does not necessarily require discontinuation of its use.

What precautions should be taken?

  • Before applying a retinol treatment to your face, we recommend performing askin tolerance test. In other words, apply a few drops of the product in question behind the ear, on the wrist, or in the crook of the arm and observe what happens. If a significant skin reaction occurs, do not apply the retinol treatment to your face.

  • We advise you to allow your skin time to adapt to retinol to prevent it from reacting too intensely. You can thus start by using a retinol treatment every two or three days, then gradually increase the frequency of application, but always in the evening.

  • It may also be relevant to pair this active ingredient with a product containing a highly moisturizing ingredient, such as hyaluronic acid, to counteract the potential drying effect of retinol. For example, for a smoothed and hydrated skin upon waking, you can apply a few drops of our plumping serum with hyaluronic acid, followed by a dab of firming cream with retinol, during your evening beauty routine.

Alcohol.

These ingredients can appear in various forms in a cosmetic product: Alcohol Denat, SD Alcohol 40-B,SD Alcohol 40-A,SD Alcohol 40,SD Alcohol 39-B,SD Alcohol 38-B,SD Alcohol 3-B,Polyvinyl Alcohol or isopropyl alcohol.These compounds disrupt the skin's natural hydrolipidic film, leading to dryness, cracks, irritation, tightness, and vulnerability to external aggressions. Moreover, they can exacerbate certain skin conditions such as eczema, psoriasis, or rosacea.

Take note! Benzyl alcohol (INCI: Benzyl Alcohol), which can also be referred to as phenylmethyl alcohol, is an effective ingredient for inhibiting the proliferation of bacteria within the product. Introduced in small doses (< 1%), its drying effect is minimal. Moreover, itis on the list of 26 allergens regulated by Europe and it is approved for use in organic products. For this reason, it is present in several of our serums at a concentration of less than 1%.

The Sodium Lauryl Sulfate (SLS).

Sodium lauryl sulfate (SLS), also known as sodium lauryl sulfate (LSS) or sodium dodecyl sulfate (SDS), is a powerful detergent and a surfactant. It is found in household products for its excellent degreasing power , but also in hygiene products such as toothpastes, shampoos, shaving foams, soaps, etc... This foaming agent is now criticized for two main reasons:

  1. Its irritating effect:

    Its detergent properties can be too strong for some sensitive skin types, to the point of causing dryness. The SLS destroys the hydrolipidic film, which results in a feeling of tightness after cleansing. It also alters the proteins of the membranes of skin and eye cells, which can lead to irritation and redness. For this reason, shower gel and bath product manufacturers are using it less and less, and prefer the ethoxylated version (SLES = sodium laureth sulfate), which is less abrasive, but its manufacturing process is highly polluting. It's worth noting that SLS is still allowed in organic products, while SLES is not.

  2. Its polluting nature:
    SLS is also identified as a pollutant to the environment, animals, aquatic habitats, and even plants. REACH (European Regulation for securing the manufacture and use of chemical substances) classifies this substance as ecotoxic.

As a precautionary principle, Typology does not incorporate sulfates into its cleansing products for the face and hair. Find here our blacklist of ingredients.

Some antimicrobial preservatives.

To prevent the growth and colonization of bacteria, synthetic preservatives are often added to cosmetic formulas. In the event of an allergic reaction to a cosmetic product, these are often the culprits.

For instance, one might find phenoxyethanol. This compound can cause skin allergies, neurological disorders, as well as effects on reproduction. Moreover, the National Agency for the Safety of Medicines and Health Products attributes to this preservative side effects such as a moderate to severe eye irritation.

Furthermore, certain treatments contain parabens due to their antimicrobial properties. However, these compounds are recognized endocrine disruptors (= which disrupt hormonal balance). In addition, they are potential skin irritants. Therefore, avoid choosing cosmetic products that contain, for example, Butylparaben or Propylparaben on their INCI list.

It's worth noting, manufacturers have replaced these preservatives with other ingredients such as MCIT (methylchloroisothiazolinone) or MIT (methylisothiazolinone). However, with continuous exposure to the same substances, the skin can sometimes develop sensitivities to these compounds.

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