Alcohol in skincare: What you need to know

If you don't want your facial care products to start moulding after just a week... I once mixed an oil-in-water lotion myself. Despite storing it in the fridge and adding tocopherol (a natural mild preservative), the lotion had gone bad after just two weeks. Without alcohol or other effective preservatives, it was simply impossible to stop the growth of bacteria. 

Problems usually arise with high concentrations or unsuitable skin types:

So-called 'bad alcohols' such as ethanol can dry out the skin in higher concentrations. They remove important fats from both the sebum (sebum lipids) and the uppermost layer of skin (epidermal lipids). This weakens the skin barrier and makes it more susceptible to irritation.

In the case of oily or acne-prone skin, such alcohols do reduce shine in the short term because they remove excess sebum. In the long term, however, the effect is reversed: denatured alcohol in particular actually stimulates sebum production even more – the skin shines more than before.

Irritating alcohols can disrupt the balance of the skin flora and kill healthy bacteria. They remove lipids from the skin layer, which allows active ingredients such as vitamin C or retinol to penetrate better, but at the same time also allows pollutants such as fine dust or microorganisms to pass through more easily.

Once the barrier is weakened and the moisture balance is disturbed, alcohol can promote oxidative stress in the long term – a factor that contributes to premature skin aging.

Alcohol fulfils several functions in cosmetics. One of the most important reasons for its use is preservation: it has antimicrobial and antibacterial properties, inhibiting the growth of bacteria, yeasts and moulds.

In concentrations of up to around 20%, alcohol is considered to be well tolerated and non-drying. Small amounts of around 5% or less evaporate very quickly when applied – they are effective in the product but hardly remain on the skin.

Alcohol takes on additional tasks, particularly in natural cosmetics: it extracts plant-based active ingredients that are not water-soluble from natural materials, making them usable in the first place. It also replaces controversial preservatives such as parabens, which is why natural cosmetic products sometimes contain surprisingly high levels of alcohol.

Fatty alcohols, on the other hand, have a different function: they act as emulsifiers and ensure that water and oil combine to form a creamy, stable texture.

In addition, alcohol facilitates the penetration of certain active ingredients into the skin and ensures light, quickly absorbed formulations. In cleansing products, alcohol has a fat-dissolving effect. In facial toners, for example, it removes excess sebum as well as water-soluble residues – leaving the skin feeling clean and looking mattified.

Alcohol describes a whole range of chemical compounds. In cosmetics, they are simplified into two groups: so-called ‘good alcohols’ and so-called ‘bad alcohols’.

 Both conventional and natural cosmetics manufacturers often use ethanol (ethyl alcohol) when they use ‘bad alcohols’ or ‘simple alcohols’. It is almost always denatured – i.e. modified with bitter substances or chemicals to make it undrinkable. The reason for this is purely tax-related: without denaturation, it would be subject to high taxation like drinking alcohol. This has almost no effect on the cosmetics themselves. Its desired properties – as a solvent, preservative and disinfectant – remain completely intact.

So-called ‘bad alcohols’ are used because they have some very good and desirable properties:

For example, denatured alcohol, i.e. ‘SD alcohol’, ‘ethyl alcohol’ or ethanol, is an excellent solvent for plant-based active ingredients. It distributes ingredients evenly, has a disinfecting effect, promotes the absorption of active ingredients, has an astringent effect – which visually reduces the appearance of pores – and evaporates quickly.

Isopropyl alcohol (isopropanol) has a strong disinfecting effect and is used, for example, in the medical treatment of acne. It has a fat-dissolving and cooling effect and preserves products.

In cosmetics, including natural cosmetics, benzyl alcohol is often used as a preservative due to its antimicrobial properties. It is popular because of its pleasant, slightly floral scent, which is also used as a fragrance component, and improves the texture of formulations.

Typical concentrations in care products range between 5-10%. These are generally considered unproblematic, as the substances evaporate quickly and leave hardly any residue. It becomes critical at higher concentrations of around 20% or more, or for sensitive skin types (very dry, sensitive, acne-prone) with already impaired barrier function and skin flora. In these cases, alcohol can have a drying, irritating or even damaging effect. The skin may feel tight, burning or itchy. It can become more sensitive and produce more sebum.

In cosmetics, certain fatty, sugar and wax alcohols are considered 'good' or 'nourishing' alcohols because they have a moisturising and hydrating effect. Fatty and sugar alcohols usually come from plant sources such as coconut, palm, corn or sugar cane. Wax alcohols are produced synthetically or obtained from animal raw materials such as lanolin (sheep's wool) or beeswax. In their raw form, they have a thicker, waxy consistency. 

'Good alcohols' act as emulsifiers and thickeners in skin care products: they stabilise emulsions, improve texture and make creams or lotions smooth and easy to apply. They form a protective layer on the skin that binds moisture, strengthens the skin barrier and prevents dryness. The result is a softer, smoother complexion – fine lines can appear less visible.

Their strengths lie in their good compatibility with almost all skin types. Dry and sensitive skin benefits from hydration and soothing. For oily or acne-prone skin, they are non-comedogenic and do not overstimulate sebum production, as long as balanced formulations are used. Overall, they promote a stable skin barrier and support the absorption of other active ingredients.

1. Dry skin

Dry skin already suffers from a lack of oil and moisture. Simple alcohols such as ethanol can further weaken the skin barrier, increase water loss and exacerbate dryness. They should therefore be avoided. Fatty alcohols (e.g. cetyl alcohol), on the other hand, are beneficial as they bind moisture and keep the skin supple.

2. Oily skin

Oily skin has very active sebaceous glands and produces a relatively large amount of oil. In small quantities, for example in toners, simple alcohols such as ethanol can be helpful in removing excess sebum and clearing pores.  

However, caution is advised with higher concentrations: they can dry out the skin and stimulate sebum production to overcompensate. Fatty alcohols are safe for oily skin and do not affect its balance.

3. Mature & aging skin

As we age, our skin inevitably loses elasticity, smoothness and tone. Age-related lipid loss makes the skin barrier less resistant. The aging process begins with a slowdown in cell renewal, often starting as early as around the age of 25. From around the age of 40, signs of skin aging become clearly visible and we refer to this as mature skin. However, factors such as genetics, UV radiation, environmental pollution and stress can cause the skin to age earlier. In this context, drying alcohols in high concentrations are unsuitable for aging and mature skin, as they can further impair the already reduced barrier function. Moisturising and nourishing fatty alcohols are more suitable at this stage of life, as they protect the skin and keep it supple.

4. Sensitive skin

Sensitive skin reacts particularly sensitively to environmental stimuli. Short-chain, i.e. ‘bad alcohols’ such as ethanol, should therefore be avoided at all costs, as they can cause irritation and redness. Instead, sensitive skin should opt for minimalist products containing fatty alcohols and soothing ingredients such as shell ginger or white rose cells. 

5. Acne-prone skin

Drying alcohols have a short-term disinfecting and degreasing effect. However, studies show that ethanol, for example, can actually increase production in the sebaceous glands, which aggravates acne. Acne-prone skin therefore benefits more from products containing fatty alcohols, which moisturise, strengthen the skin barrier and are generally non-comedogenic.

One exception is Malassezia folliculitis or fungal acne, which is often confused with classic acne. Its trigger, the yeast Malassezia, is a normal part of the human skin flora. In the case of fungal acne, there is excessive growth of this yeast fungus. Its growth is further promoted by fatty alcohols such as cetearyl alcohol, which create a moist environment, thus aggravating the condition.

6. Normal & combination skin

Normal and combination skin usually tolerate moderate amounts of denatured alcohol such as ethanol well. In commercially available skincare products, typical concentrations range between 0.5% and 20%. While studies and recommendations show that concentrations of up to about 10% are usually unproblematic, higher proportions can dry out the skin.

Fatty alcohols are generally not a problem for normal and combination skin and are non-comedogenic. In cosmetic products, they are usually found in concentrations of 1 – 10% and are often combined with other nourishing lipids such as ceramides.

Rich creams with higher proportions of fatty alcohols (above 5 – 10%) can cause a slight greasy feeling or shine in the oily T-zone, i.e. the forehead, nose and chin. Lighter formulations with 2 – 5% fatty alcohols can help here.

A glance at the INCI list helps with the selection: for combination skin, products are recommended in which fatty alcohols such as cetyl alcohol appear third or later in the list – this indicates moderate amounts.

Basically, the effect of alcohol on the skin depends largely on the overall formulation and the amount of alcohol used. If the product contains sufficient moisturising ingredients in addition to alcohol, this can counteract the drying effect. Producers of natural Japanese skincare products attach great importance to ensuring good hydration at every step, even with facial cleansers and toners. The following table is therefore intended as a guide, but cannot make any statements about individual formulations or individual tolerances.