How Effective is Allantoin?
The name is Toin. Alan Toin. Awful opener. Today I am rambling on about another cosmetic ingredient called Allantoin, no relation to Alan Toin. Allantoin can be found primarily in skincare products which aim to soothe the skin, things like after sun lotions and topical eczema treatments. It’s not quite as common as ingredients like Glycerine or Panthenol but it's certainly up there as a true ‘tried and tested’ staple in the skincare space and with very good reason.
What is Allantoin?
Allantoin has a long history being isolated in 1800 by an Italian physician. A few decades later a French chemist identified what he would later dub ‘l’acide allantoique’ present in the fluid of the ‘allantois’ which is a sac like structure involved in embryonic growth. A couple of German chemists then decided that was a stupid name and after synthesising the compound from uric acid, dubbed it ‘allantoin’.
Allantoin is a diureide of glyoxylic acid and as it is an intermediary in numerous biological processes, it is present in most organisms including plants, animals and bacteria.
Although Allantoin is found in extracts of the comfrey plant, almost all commercially used Allantoin is lab synthesised. For formulators, it presents as a white, crystalline, odourless, mid-weight powder. It is water soluble but typically requires warm water to increase solubility and even at 75 °C has a fairly low solubility of 4g/100ml.
Benefits & Function
The official INCI functions of allantoin are:
Skin conditioning : Maintains skin in good condition.
Skin protecting: Helps to avoid the harmful effects of various external factors on the skin.
Soothing: Helps to reduce general skin discomfort.
Is Allantoin Safe for the skin?
Allantoin is considered a very safe cosmetic ingredient based on numerous assays and studies with most data prior to 2010 summarised by the CIR (Cosmetic Ingredient Review) Expert Panel in this paper. One of the key indicators of its safety is not only a lack of irritation, genotoxicity and carcinogenicity in general but that it is regularly applied topically as high as 4% concentration on wounds and broken skin in a therapeutic setting and classic makers of adverse reactions such as inflammation, itching and redness do not occur.
Allantoin is typically used in the 0.1-2% concentration for general personal care and cosmetic products but in experimental treatment settings can often be seen in formulas in the 4-6% range.
How effective is it?
Numerous studies have shown the wide therapeutic value of allantoin:
Anti-Aging Potential: An interesting 2021 study showed that intra-peritoneal (i.p) injection of allantoin resulted in reduced markers of oxidative stress, an increase in lipogenesis and also interactions with age-related cellular pathways as a reduction in the activity of collagenase was observed; collagenase is responsible for the breakdown of collagen, which is a normal part of advancing age. It should be noted that this study measured the impact of injected, not dermal, allantoin application but the observation of a reduction in collagenase activity is especially relevant to skincare as a reduction in collagen production is one of the key factors contributing to the appearance of ‘old’ skin as it is a key structural protein. It would be worth taking a look at this from a purely dermal perspective.
Anti-Inflammatory: An investigation into the mechanism of action of allantoin in the context of wound repair and healing that looked at 30 individual studies summarised that allantoin ultimately helps wound repair by increasing the speed at which damaged tissue switches from an inflammatory state to a proliferative state. As the inflammatory state prevents remodelling of damaged epithelial tissue, triggering this switch to a ‘repair’ state at a faster pace leads to faster healing times. Allantoin appears to have inherent anti-inflammatory, anti-microbial, antioxidant and keratolytic activity, all of which are incredibly useful in the context of stimulating skin repair.
Scarring/Healing: A decent sized study from 2018 showed that when allantoin is applied alongside an onion extract in the form of a dermal patch following surgery, resultant scars were ultimately less noticeable compared to untreated participants. There were also no identified safety concerns to report. Additionally, a smaller 2020 rodent study showed that a combination application of pectin-allantoin film to the skin sped up wound healing by 25% in the treated cohort. Similar observations have been reported previously. The authors advise this could hold therapeutic promise in human trials.
An Interesting Side Note: Maggots (Lucilia Sericata) have been used for countless years to clean wounds as they consume dead tissue but leave healthy tissue completely alone. While the removal of dead tissue is an important first step in gearing up the wound for repair, this species of maggot also excretes allantoin as 10% of their nitrogenous waste which is truly remarkable. So while the little flesh-hoovers are roaming around and cleaning up, they are popping out a known tissue reparative agent. Fascinating!
What does Allantoin pair well with?
Allantoin is a superb repairing and protective agent so naturally pairs well with other ingredients that have similar roles. However, allantoin can be included in a wide variety of formulations and plays well with a multitude of other common cosmetic ingredients.
It combines particularly well with:
Panthenol – soothing, humectant
Aloe Vera – soothing, cooling
Kaolin – absorbing, cleansing, soothing
Silicones - emollient
Summary
Allantoin is an in expensive, therapeutically potent and skin-safe active that is particularly well suited to formulations where skin repairing, anti-inflammatory or soothing action is required.
Key Benefits:
· Very gentle so can be used multiple times a day
· Supports wound healing
· Is an effective anti-irritant
· Anti-aging potential
· Appropriate for all skin types
This post was written by our Chief Scientist, Dr. Edward Jones
