The active ingredient of Comfrey, allantoin, can also be of animal or synthetic origin. First discovered in 1800, this ingredient is often favored in skincare for its numerous benefits. This article provides an overview of this active component.
Allantoin: What should you know about this active ingredient?
- What is Allantoin?
- What are the benefits of allantoin?
- Are there any documented dangers and contraindications following the topical use of allantoin?
What is Allantoin?
In 1800, the Italian physician Michele Francesco Buniva and the French chemist Louis Nicolas Vauquelin first isolated allantoin. They believed it was present in the amniotic fluid. Later, in 1821, the French chemist Jean Louis Lassaigne discovered it in the fluid of the allantois and named it "allantoic acid". It was then renamed "allantoin" in 1837, when the German chemists Justus Liebig and Friedrich Wöhler synthesized it through uric acid.
Allantoin is a nitrogenous chemical compound found in many botanical extracts, particularly in the comfrey plant. It can be extracted from the leaves and roots of comfrey. The allantoin content in the root varies between 0.7% and 2.5%. Allantoin can also be found in mammalian amniotic fluid and urine or in the mucus of snails.
What are the benefits of allantoin?
Theallantoin is a highly favored ingredient in skincare for its numerous benefits.
Allantoin and its healing properties.
Healing is a natural skin repair phenomenon that can take several weeks. Allantoin is an active ingredient often known to boost the healing process. A 2010 study suggests that it plays a role in fibroblastic proliferation and the synthesis of macromolecules that make up the extracellular matrix.
Allantoin combats cellular aging.
Indeed, it has the ability to stimulate fibroblasts, cells responsible for the production of collagen. However, with age, the rate of collagen production decreases and tends to promote the appearance of wrinkles. Although this property is mentioned in scientific literature, its mechanism of action on fibroblasts is not detailed and remains unknown.
Allantoin to promote cellular regeneration.
Thanks to its keratolytic action, it would help soften the horny layer by promoting the removal of dead cells. Allantoin would eliminate corneocytes by loosening the intercellular cement or desmosomes (protein bridges), which maintain the adhesion of corneocytes to each other. By removing dead cells on the surface of the epidermis, allantoin helps to reduce pore obstruction and eliminate dandruff.
Allantoin and its anti-inflammatory activity.
In 2021, a study demonstrated that a fraction of snail mucus containing allantoin exhibited inhibitory activity against the thermal denaturation of human serum albumin, an anti-inflammatory compound. This property could be beneficial in reducing inflammation caused by theacne or an irritated scalp. However, additional research is needed to substantiate this anti-inflammatory activity.
The effect of allantoin on sebum.
Acne is often caused by an overproduction of sebum or the production of excessively thick sebum. Studies suggest that allantoin is capable of eliminating excess sebum. This property would be beneficial for acne-prone skin, but also for oily hair, which tends to produce more sebum (hyperseborrhea).
The moisturizing properties of allantoin.
Several studies have mentioned that allantoin possesses moisturizing properties, although its mode of action is not detailed. Its hydrating potential could be explained as it is a water-soluble humectant ingredient that helps increase the water content of cells by combating transepidermal water loss in the dermis. This property is beneficial in addressing skin and hair dehydration by creating a protective layer around the cuticle.
Are there any documented dangers and contraindications following the topical use of allantoin?
Due to its softening and hydrating properties, allantoin is considered safe for skin care. The United States Food and Drug Administration (FDA) has listed allantoin as an effective and safe agent for skin protection at concentrations of 0.1 to 2%. In Europe, this active ingredient is not regulated for its use in cosmetic care. It is non-toxic, non-allergenic, and non-irritating. As it regenerates skin tissues following injuries or lesions, hydrates the skin, and soothes irritations and itching associated with skin inflammation, allantoin is suitable for all skin types, even delicate and reactive skin.
Allantoin typically does not cause adverse effects when used according to the instructions on the label. However, it is not ruled out that topical treatments may cause irritation or an allergic reaction, especially if they contain other ingredients. As a precaution, it is recommended to perform a skin test in the crook of the arm to observe if a potential allergic reaction occurs. It is advisable to stop using a skincare product containing allantoin if one or more of the following reactions occur: inflammation, redness or discoloration of the skin, dryness, itching, or hives.
SILVA-BARCELLOS N. M. & al. Profile of wound healing process induced by allantoin. Acta Cirúrgica Brasileira (2010).
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).