Allantoin: What are its benefits for hair?

Allantoin serves a dual purpose of regulating the inflammatory process and soothing scalp irritations and redness. It plays a role in inhibiting COX-2, a cyclooxygenase that contributes to the production of prostaglandins, which in turn are responsible for some of the symptoms of inflammation.

Scientific studies have also shown that allantoin interferes with the activation of NF-κB, a protein involved in the immune response, at the level of p65 transactivation. Several studies have demonstrated that specific phosphorylation reactions lead to post-translational modifications that could influence the transactivation potential of p65.

This study suggested that allantoin could inhibit these phosphorylation reactions and be responsible for the inactivation of NF-kB. Thus, it could help reduce inflammation and soothe the scalp.

Allantoin helps to soften the stratum corneum by promoting the removal of dead cells. Allantoin eliminates corneocytes by loosening the intercellular cement or desmosomes (protein bridges) that maintain the adhesion of corneocytes to each other. It allows their renewal, which replaces the dead cells present on the surface of the scalp and prevents the clogging of pores. In this case, allantoin can be beneficial for individuals suffering from dandruff or even scalp crust.

Several studies have mentioned that allantoin possesses moisturizing properties and is often used in creams or lotions as a hydrating agent. However, its mode of action is not detailed in scientific literature. Its hydrating potential could be explained by the fact that it is a water-soluble humectant ingredient: it helps increase the water content of cells by combating transepidermal water loss in the dermis. Thus, it helps fight against a dry scalp and prevent inflammation. Allantoin is also effective in moisturizing hair by creating a protective layer on the surface of the cuticle, helping to maintain their shine.

An overproduction of sebum due to hyperactive sebaceous glands can cause scalp itchiness and make the hair oily. It is often read that allantoin could counter this problem, but is this really the case?

Allantoin is an active ingredient used in the formulation of deodorants. It has often been suggested that it is capable of regulating sebum secretion and eliminating excess in cases of hyperseborrhea. However, this property has never been verified in scientific studies, and therefore it is not possible to assert that allantoin possesses sebum-regulating properties.

To reap its hair benefits, one can adopt a routine composed of allantoin-based products. Notably, there are many soothing shampoos available for sensitive scalps that contain allantoin. They help to soothe and reduce scalp itchiness, caused by environmental factors such as pollution or stress.

Allantoin is also found in conditioners or hair masks to soften the hair and make it shine. Allantoin is an extremely beneficial ingredient for all hair types and is often used in children's hair products. To benefit from its advantages, it is recommended to favor treatments where the concentration of allantoin is at least 0.5% of the total weight.

• IGILE G. O. & al. Rapid method for the identification and quantification of allantoin in body creams and lotions for regulatory activities. International Journal of Current Microbiology and Applied Sciences (2014).

• SAVIĆ V. L. & al. Comparative study of the biological activity of allantoin and aqueous extract of the comfrey root. Phytotherapy Research (2015).

• DINICA R. M. & al. Allantoin from valuable romanian animal and plant sources with promising anti-inflammatory activity as a nutricosmetic ingredient. Sustainability (2021).