What Is Willow Bark?
Willow bark is the bark from several types of willow tree. It has been used for centuries for medicinal purposes due to an active ingredient called salicin which has similar effects to aspirin, helping to relieve pain.
Willow bark has also been used in traditional skincare for hundreds of years, this is due to the same ingredient, salicin. Salicin not only may have pain-relieving abilities but it is also the compound that salicylic acid is derived from. Salicylic acid is widely used in skincare formulations to help exfoliate the skin, helping to remove dead skin cells, reduce the appearance of fine lines and may support acne treatment.
Willow bark extract can be derived from most willow species but generally, the white or black willow trees is used for willow bark extract. This is because the white and black willow bark trees have a high salicin content.
Willow Bark
the good: Helps to exfoliate the skin, removing dead skin cells, reducing the appearance of fine lines and supporting acne treatments.
the not so good: With any plant-derived ingredient, the extract or compound you are using isn’t just one ingredient, it is a mixture of many different plant compounds. This can increase the risk of irritation and sensitivity. If you have sensitive skin, natural identicals or synthetics are generally safer as they are less likely to cause irritation and are often more rigorously tested.
Who is it for? All skin types except those that have an identified allergy to it.
Synergetic ingredients: Works well with most ingredients
Keep an eye on: Make sure to use willow bark and salicylic acid products carefully as they can cause irritation and may reduce the integrity the skin’s natural protective barrier. A high concentration may not always be best.
Why Is Willow Bark Used?
Willow bark like most plant-derived ingredients is actually made up of a number of different compounds. It is not just one ingredient. It contains compounds such as salicin, tannins, flavonoids, minerals and polyphenols.
Salicin
Salicin is the main ingredient that is associated with willow bark extract. It is the ingredient that salicylic acid can be derived from. Whilst salicin itself is not well studied in the context of skincare. It is thought to help support skin cell turnover, exfoliation and may help to reduce the appearance of fine lines and overall complexion.
Polyphenols
Polyphenols are a class of compounds that have been linked to having antioxidant abilities. Antioxidants help to reduce the damage caused by sun exposure and environmental factors such as pollution. Antioxidants work by minimising the damage caused by free radicals. Polyphenols have also been linked to soothing and antibacteiral properties for the skin.
Tannins
Tannins are an astringent ingredient which means that they help to contrict the skin. This can temporarily improve the appearance of pores and make the skin look firmer. Atringent ingredients have traditionally been used in products such as toners to support a reduction in sebum produced by the skin. More recently astringent products have been phased out of use due to the temporary nature of the effects and the dryness that is often associated with the type of product they are used in.
Flavonoids
Flavonoids are a type of polyphenol that are high in antioxidant abilities. They are generally considered to help mitigate the effects of UV damage. However, it is important to remember that avoiding sun exposure and using sunscreen is the most effective way of protecting the skin against sun damage and the aging that is often associated with UV rays.
Is Willow Bark Safe?
As is the case with any plant-derived ingredient, it can be difficult to know the safety of the ingredient as there are so many compounds present in the ingredient itself. This is often compounded by the fact that much of the research into plant-derived ingredients does not focus on the topical use. However, willow bark extract does seem to be safe from the studies that have been completed with the main concern being that it may cause irritation and sensitivity in some people. The greatest concern is for those who have an allergy to salicylates, for those who do, willow bark should be avoided.
References:
Ishikado A, Sono Y, Matsumoto M, et al. Willow bark extract increases antioxidant enzymes and reduces oxidative stress through activation of Nrf2 in vascular endothelial cells and Caenorhabditis elegans. Free Radic Biol Med. 2013;65:1506-1515.
Shara M, Stohs SJ. Efficacy and Safety of White Willow Bark (Salix alba) Extracts. Phytother Res. 2015 Aug;29(8):1112-6
