Eyelash serums and mascaras: what risks do these products pose when applied near the eyes?

The eyelash and eyebrow serums are applied to very sensitive areas in immediate proximity to the eye. When a cosmetic product is placed at the lash base, it can gradually migrate towards the ocular surface under the combined effect of blinking, perspiration and skin warmth. This phenomenon of "migration" typically occurs within minutes and explains why certain treatments can cause burning sensations, stinging, redness or ocular discomfort. In some cases, this repeated exposure may promote the onset of conjunctivitis, blepharitis or, more rarely, eye infections.

From a regulatory standpoint, European legislation requires that any cosmetic product intended for the eye‐contour area undergo specific tolerance tests before being placed on the market. These assessments aim to minimise the risk of irritation and ocular toxicity.

That said, depending on individual sensitivity, adverse effects remain possible. The cutaneous and ocular reactions associated with products used near the eyes are also well documented in the literature. One study assessed the irritant potential of several mascaras using occlusive patch tests in healthy volunteers. Two out of seven mascaras induced skin inflammation with redness, necessitating premature termination of the tests. These products were distinguished by their formulation based on solvents derived from petroleum distillates, unlike the other mascaras formulated as conventional emulsions. Some also contained surfactants that are strongly irritating, known to impair the skin barrier, such as sodium lauryl sulfate.

Beyond acute irritations, the prolonged and repeated use of products applied to the eyelashes can also be associated with more insidious ocular damage. Several clinical case reports have described complications related to chronic mascara use, including conjunctival lesions, eyelid dermatitis, infectious keratitis and even obstructions of the lacrimal drainage pathways. In one case series, two patients presented with non-melanocytic conjunctival pigment deposits after years of intensive mascara application, while another patient developed an obstruction of the nasolacrimal duct caused by a conglomerate of product residues. These observations suggest that pigments and particles from eye products can accumulate progressively on the ocular surface or within the tear drainage pathways.

However, it is important to qualify this: many people apply mascara or eyelash serums daily without developing complications, as is often observed in actresses or models subjected to repeated make-up. The occurrence of problems thus appears less related to frequency of use than to the quality of make-up removal. Inadequate cleansing can promote the progressive accumulation of cosmetic residues on the eyelids, the ocular surface or within the tear ducts, thereby increasing the risk of irritation or infection. Careful make-up removal each evening using a suitable product and without excessive rubbing is therefore essential to preserve ocular health.

This study emphasises that cosmetics applied to the eyelashes and eyebrows are not innocuous in the long term, particularly when used without meticulous make-up removal.

The risks associated with eyelash and eyebrow serums also and above all depend on the ingredients they contain. Certain active compounds, although highly effective at stimulating the hair growth, can cause significant adverse effects, particularly when used over prolonged periods in close proximity to the eye.

Prostaglandin and its derivatives: ingredients to avoid.

Prostaglandin analogues are arguably the most controversial ingredients in eyelash and eyebrow serums. Originally, prostaglandins are hormones involved in numerous physiological processes. Some of their derivatives are also used in ophthalmology, particularly in eye drops for the treatment of glaucoma, where they serve to reduce intraocular pressure. One of their well-documented side effects is a marked stimulation of eyelash growth, observed in treated patients.

It was on the basis of this clinical observation that these molecules were repurposed for cosmetic use to promote the lengthening and thickening of eyelashes and eyebrows. While their efficacy is undeniable, their tolerance profile is problematic. Numerous adverse effects have been reported: eyelid redness and oedema, burning or tingling sensations, tearing, skin hyperpigmentation along the lash line, persistent iris darkening, reduced intraocular pressure and even unwanted hair growth in the areas in contact with the product.

From a regulatory standpoint, these substances are subject to increased monitoring. In the United States, their use in cosmetic products for the eyes is strictly regulated by the FDA. In Europe, the German Federal Institute for Risk Assessment determined as early as 2018 that prostaglandin derivatives used to stimulate eyelash growth could pose a health risk, even at the concentrations employed in cosmetics. Following a call for data launched in 2020, the European Scientific Committee on Consumer Safety (CSSC) concluded in 2022 that the use of these analogues in cosmetic products was not without risks for the consumer.

Good to know : In INCI lists, prostaglandin analogues are often identifiable by the presence of the segment "prost", for example: Isopropyl Cloprostenate, Ethyl Tafluprostamide, Dehydrolatanoprost, Bimatoprost or Cyclopropyl Bimatoprost.

Phenoxyethanol, a suspected ocular irritant that should be approached with caution.

Phenoxyethanol is a preservative synthetic compound used in cosmetics to limit microbial proliferation. Although authorised by European regulations within certain concentration limits, it is frequently singled out for its potential to cause eye irritation.

Several health authorities, including the National Agency for the Safety of Medicines and Health Products (ANSM), recognise that the phenoxyethanol can cause moderate to severe eye irritation. Instances of burning sensations, redness and tearing have been reported, raising concerns when it is used in products applied in the immediate vicinity of the eye. In an eyelash or eyebrow serum, where the risk of migration onto the ocular surface is real, its presence may therefore be questionable.

Note : The list of ingredients mentioned above is not exhaustive. Other components may be problematic in serums intended for eyelashes and eyebrows. Among these are certain irritating or sensitising preservatives, such as formaldehyde-releasing agents (DMDM Hydantoin, Imidazolidinyl Urea...) or the Benzalkonium Chloride, known for its potential to irritate the ocular surface. Fragrances and perfume allergens, for example limonene, linalool or geraniol, even at low concentrations, can also trigger reactions in sensitive individuals. Finally, certain denatured alcohols may cause a tingling sensation around the eyes.

• WESSMAN C. & al. Mascaras may cause irritant contact dermatitis. International Journal of Cosmetic Science (2002).

• MEYER D. & al. Ocular manifestations of long-term mascara use. Ophthalmic Plastic & Reconstructive Surgery (2009).

• Comité scientifique spécialisé temporaire. Utilisation du phénoxyéthanol dans les produits cosmétique. ANSM (2017).

• Scientific Committee on Consumer Safety (SCCS). Opinion on prostaglandins and prostaglandin-analogues used in cosmetic products (2022).

• DIMRI A. G. Microbial contamination of eye make up product: Herbal mascara a concern. Universities Journal of Phytochemistry and Ayurvedic Heights (2022).

• KUNDER R. & al. Microbiological contamination linked to the usage of mascara among waterproof and non-waterproof brands and tear film assessment. AJ Journal of Medical Sciences (2024).