Are there any dangers associated with the use of a lip serum?

Lip serums are relatively recent formulations in the beauty universe. However, they are becoming increasingly prevalent due to their benefits, namely hydration, protection, and plumping effect. The compositions, and therefore the I.N.C.I. lists, vary depending on the brand.

Some may thus contain compounds deemed undesirable for health once ingested, even if they are seemingly harmless when applied topically. This raises concerns for a product used daily, and even more so for pregnant women, given the fact that the product applied to the lips ends up being largely ingested. Studies have estimated that we ingest between 20 to 50 mg of lip care products per day. However, some lip serums may contain ingredients implicated for their potential health risks through oral exposure:

• Some serums contain mineral oils derived from petrochemicals. The most common ones are listed under the INCI names "
  Hydrogenated polyisobutene" and "Polybutene".These synthetic oils generally act as lubricants, they have the ability to strengthen the moisture barrier. However, these are derived from chemical reactions harmful to the environment. Moreover, they can accumulate in the liver and create inflammatory reactions, the exact repercussions of which are still unknown. Vaseline (INCI name: "Petrolatum") is also a petroleum derivative that often tops the list in certain lipsticks and serums.This ingredient is banned in cosmetics in Europe, except "if the complete refining history is known and it can be demonstrated that the substance from which it is produced is not carcinogenic."

• Some lip serums also containcolourants in the form of nanoparticles such as titanium dioxide(INCI name: CI 77891). In 2006, the International Agency for Research on Cancer (IARC) classified titanium dioxide (TiO2) in the group of substances "possibly carcinogenic to humans" (group 2B): when inhaled, regardless of the particle size (nano or not).

• It is also advisable to avoid a lip serum containing phenoxyethanol. This synthetic preservative, known by the acronym EGPhE, is increasingly controversial. Indeed, this compound can cause skin allergies, neurological disorders as well as effects on reproduction.

• The BHA (butylated hydroxyanisole) and the BHT (butylated hydroxytoluene) can also be present in lip serums as preservatives, for their antioxidant properties. To identify them, they are usually at the end of the INCI list. They prevent oxidation and rancidity of formulas. However, these two substances are suspected of being endocrine disruptors. In a nutshell, endocrine disruptors are molecules capable of deregulating the hormonal system. Moreover, the A.R.T.A.C. (French Association for Anti-Cancer Therapeutic Research) classifies them among potentially carcinogenic substances. Finally, both molecules are also known to be sensitising, thus being a source of allergies.

• Silicones are sometimes present in lip serums. Although not all silicones have harmful effects on health and some are completely safe to use, cyclotetrasiloxane (D4) and cyclopentasiloxane (D5) are both suspected of being endocrine disruptors . Therefore, these two ingredients should be avoided when choosing a lip serum.

Our plumping lip serum is vegan and formulated without mineral oils, beeswax, and pigments. It is suitable for both normal and dry to very dry lips. It provides a comprehensive plumping and smoothing action on the lips and lip contour. The lips are hydrated and softened, and the lip contour is smoother and better defined. It contains low molecular weighthyaluronic acid (200 to 400 kDa) that penetrates deeply and instantly hydrates the skin. It also contains atripeptide (INCI name: Palmitoyl Tripeptide-38) that activates the synthesis of elastin and collagen.

• EFSA (European Food Safety Authority). Scientific opinion on mineral oil hydrocarbons in food. EFSA Journal (2012).

• GROB K. & al. Mineral oil and synthetic hydrocarbons in cosmetic lip products. International Journal of Cosmetic Science (2016).

• FLORES E. M. M. & al. Toxic and potentially toxic elements determination in cosmetics used for make-up: A critical review. Analytica Chimica Acta (2020).