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

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

From a regulatory standpoint, European legislation mandates that any cosmetic product intended for the eye contour area undergo specific tolerance tests before entering the market. These evaluations are designed to minimize the risks of ocular irritation and toxicity.

Nevertheless, depending on individual sensitivity, adverse effects remain possible. The cutaneous and ocular reactions related to products used near the eyes are well documented in the literature. One study assessed the irritant potential of several mascaras using occlusive tests in healthy volunteers. Two out of seven mascaras induced skin inflammation with redness, requiring 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 highly irritating and known to disrupt the skin barrier, such as sodium lauryl sulfate.

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

However, it is important to put this into perspective: many people use mascara or lash serums daily without developing complications, as is often the case with actresses or models exposed to repeated makeup. The onset of problems thus appears less related to frequency of use than to the quality of makeup removal. Inadequate cleansing can promote the gradual accumulation of cosmetic residues on the eyelids, the ocular surface, or the tear ducts, increasing the risk of irritation or infection. Careful makeup removal, performed each evening with a suitable product and without excessive rubbing, is therefore essential to preserve ocular health.

This study reminds us that cosmetics applied to the eyelashes and eyebrows are not harmless in the long term, especially when used without rigorous makeup removal.

The risks associated with eyelash and eyebrow serums also—and primarily—depend on the ingredients they contain. Certain active agents, while highly effective at stimulating the hair growth, can cause significant side effects, especially when used over extended periods in close proximity to the eye.

Prostaglandin and its derivatives: ingredients to avoid.

Prostaglandin analogs 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, notably in eye drops for the treatment of glaucoma, where they help reduce intraocular pressure. One of their well-documented side effects is a marked stimulation of eyelash growth, observed in treated patients.

On the basis of this clinical observation, 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: redness and edema of the eyelids, burning or tingling sensations, tearing, skin hyperpigmentation at the lash line, sustained iris darkening, decreased intraocular pressure, and unwanted hair growth in areas of product contact.

In regulatory terms, these substances are subject to heightened scrutiny. In the United States, their use in eye cosmetic products 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 concentrations used in cosmetics. Following a call for data launched in 2020, the European Scientific Committee on Consumer Safety (SCCS) concluded in 2022 that the use of these analogs in cosmetic products was not without risk 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 warrants caution.

Phenoxyethanol is a preservative synthetic compound used in cosmetics to limit microbial proliferation. Although authorized by European regulations within certain concentration limits, it is regularly flagged for its potential to cause ocular irritation.

Several health authorities, including the French National Agency for the Safety of Medicines and Health Products (ANSM), recognize that the phenoxyethanol can cause moderate to severe ocular irritation. Cases of burning, redness, and tearing sensations have been reported, raising concerns when it is used in treatments applied in close proximity to the eye. In an eyelash or eyebrow serum, where migration toward the ocular surface is a realistic risk, its presence can therefore be questioned.

Note : The list of ingredients mentioned above is not exhaustive. Other components may be problematic in eyelash and eyebrow serums. Among these, certain irritating or sensitizing preservatives can be cited, such as formaldehyde-releasing agents (DMDM Hydantoin, Imidazolidinyl Urea...) or the Benzalkonium Chloride, known for its irritant potential on the ocular surface. Fragrances and fragrance allergens, such as limonene, linalool, or geraniol, even at low levels, can also trigger reactions in sensitive individuals. Finally, certain denatured alcohols can cause stinging sensations 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).