The skin barrier: cleansing without damage and restoring it

The skin barrier: how to avoid damaging it when cleansing and support its repair

With targeted support, skin barrier function in most people shows measurable recovery within 2 to 4 weeks — the time needed to replenish the lipid matrix of the stratum corneum and achieve a sustained reduction in TEWL. Below, we explain what to use during this time, what to avoid and when to see a dermatologist. The most common cause of damage is something you do every day — washing your face.

What is the skin barrier and how does it become compromised?

The barrier is a quantifiable structure: thickness, lipid ratios, pH and TEWL have reference ranges against which disruption is measured.

The stratum corneum and lipid matrix: how the skin barrier is built. Ceramides and the skin barrier are inseparably linked. The stratum corneum is often described using the bricks and mortar metaphor (Elias, J Invest Dermatol, 2005). The bricks are corneocytes: flattened, terminally differentiated cells without a nucleus, filled with keratin and natural moisturising factor. The mortar is the intercellular lipid matrix, which accounts for only ~15% of the mass of the stratum corneum, yet is the layer that limits the rate of transport of water and xenobiotics.
The lipid matrix has three main components by weight: approximately 50% ceramides, 25% cholesterol and 15% free fatty acids. There are more than 12 molecular subtypes of ceramides (NS, NP, NH, AS, AP, AH, EOS, EOP, EOH and others), which differ in chain length and type of sphingoid base (Madison, J Invest Dermatol, 2003). These lipids arrange themselves into two coexisting lamellar phases: the short-periodicity phase (SPP, ~6 nm) and long-periodicity phase (LPP, ~13 nm). The LPP is unique to the mammalian stratum corneum and is the main site of the permeability barrier (Bouwstra & Ponec, Biochim Biophys Acta, 2006).
Model studies show that ceramides, cholesterol and free fatty acids must be present in an approximately equimolar ratio to form optimal orthorhombic lateral packing — the densest arrangement, capable of providing an effective barrier (Mojumdar et al., Langmuir, 2014). Deviations from this ratio, such as an excess of monounsaturated fatty acids or a shortage of ceramides, shift the arrangement towards a looser hexagonal phase, which is less effective at retaining water. Another important element is the corneocyte lipid envelope: ceramides covalently bound to the proteins involucrin and envoplakin surround each corneocyte (Proksch, Brandner & Jensen, Exp Dermatol, 2008). This covalent linkage provides mechanical and chemical reinforcement between the bricks and mortar. We will cover the individual types of ceramides and their roles in a separate guide.

Natural moisturising factor (NMF) and hydration

Inside corneocytes is a mixture of hygroscopic substances called natural moisturising factor (NMF), which accounts for approximately 20 to 30% of their dry weight (Verdier-Sévrain & Bonté, J Cosmet Dermatol, 2007).
NMF composition: free amino acids account for approximately 40%, pyrrolidone carboxylic acid (PCA) 12%, lactate 12%, urea 7% and inorganic salts the remainder. NMF is formed mainly through the proteolytic breakdown of filaggrin during keratinisation. Its role is to bind water from the surroundings, maintain the flexibility of the stratum corneum and provide the optimal pH for the enzymes responsible for desquamation — the shedding of dead corneocytes. This is precisely why urea, an endogenous component of NMF, is so effective in topical formulations. At a concentration of 3 to 10%, it acts as a humectant and NMF mimic, replenishes the endogenous urea pool and reduces TEWL; at concentrations above 10%, it also has a keratolytic effect (Celleno, Dermatol Ther, 2018).
Topical urea also upregulates aquaporin-3 and -9 (water–glycerol channels), keratinocyte differentiation genes (involucrin, loricrin, filaggrin) and the expression of antimicrobial peptides.

Transepidermal water loss (TEWL): how we measure the barrier

TEWL, or transepidermal water loss, is the primary objective indicator of barrier function. It is measured using a specialist instrument, a Tewameter, which records the diffusive flow of water through the skin in grams per square metre per hour (g/m²/h). A 2018 systematic review and meta-analysis covering more than 50 studies established reference TEWL values for healthy adult skin: forearm 7.36 g/m²/h (95% confidence interval 7.07 to 7.65), cheek 9.31 g/m²/h and forehead 13.59 g/m²/h (Akdeniz et al., Br J Dermatol, 2018). An increase in TEWL to more than twice the baseline value indicates clinically significant barrier disruption.
What this means for you: TEWL rises before visible redness or flaking appears. The barrier is compromised several hours before you notice the first symptoms. A feeling of tightness after washing or stinging when applying a serum are early subjective signs of what is already happening at a molecular level.

What compromises the skin barrier: cleansing, pH and the environment

The most common daily cause of barrier disruption is incorrect cleansing. Anionic surfactants such as sodium lauryl sulphate (SLS) directly wash lipids out of the stratum corneum. Korting and colleagues investigated pH-dependent skin irritation caused by SLS and found that an alkaline pH increases the surfactant's potential to damage the barrier, with elevated TEWL persisting for several hours after exposure (Korting et al., Acta Derm Venereol, 1990).
The second factor is the pH of the skin itself. Measurements on the forearms and foreheads of 330 healthy adults gave an average surface pH of 4.7, significantly below the historical textbook value of 5.5 (Lambers et al., Int J Cosmet Sci, 2006). This mildly acidic environment is necessary for ceramide-processing enzymes to function: β-glucocerebrosidase and acid sphingomyelinase have optimal pH ranges between 4.5 and 5.5 (Holleran, Takagi & Uchida, FEBS Lett, 2006).
An alkaline surface inhibits these enzymes, slowing lipid matrix repair; pH returns to normal within several hours after a single alkaline wash, but repeated daily exposure compounds the cumulative effect. These two factors are joined by over-exfoliation (combining AHA, BHA and retinoids at the same time), cold, wind and UV radiation, which increase TEWL through environmental exposure, and conditions associated with a compromised barrier (atopic dermatitis through filaggrin gene mutations, and rosacea and seborrhoeic dermatitis through inflammatory dysregulation).
Other factors include chronic stress, age and hormonal changes — their effects are supported by biochemical evidence, but the size of their clinical impact is less well quantified. If you notice significant inflammation, flaking or persistent redness, it may be eczema, rosacea or seborrhoeic dermatitis. In these cases, consulting a dermatologist is the right step.
This article is educational and covers cosmetic skincare, not medical treatment.

The skin barrier and face washing: why this is the most common question

Cleansing is the only step in your routine that challenges the barrier both mechanically and chemically every day — water, surfactants, friction and temperature, all in one routine.
The most common ways cleansing damages the barrier: traditional toilet soap typically has a pH of 9 to 10 — the saponification of fatty acids with alkalis produces an alkaline product, as illustrated by measurements of 32 retail soaps and shampoos (Tarun et al., Indian J Dermatol, 2014), excessive use of sulphate-based gels (SLS, SLES), hot water above 37 °C, mechanical friction from a terry towel and excessive frequency (more than 2× a day).
The answer is not to cleanse less, but to cleanse correctly: at a pH of around 5.5 using synthetic cleansers (syndets) or natural saponins, with lukewarm water below 37 °C, gentle patting and, ideally, without double cleansing every evening unless you wear heavy make-up or water-resistant SPF.
For dry and sensitive skin, a very gentle gel is enough in the morning; in the evening, use a gentle cleanser followed by a restorative formulation while the skin is still damp, to reduce TEWL during the first 15 minutes after washing. You can find a detailed comparison of cleanser types, pH measurements and practical surfactant selection in our guide to cleansing.

How to repair a weakened skin barrier: active ingredients and routine

Skin barrier repair rests on three pillars: replenishing lipids (ceramides, cholesterol and free fatty acids in an approximately equimolar ratio), retaining water (humectants such as glycerin, urea 3 to 10%, panthenol and NMF) and stimulating repair (niacinamide, panthenol).
With lipid-mimicking support, barrier function measurably improves within 2 to 4 weeks (Spada, Barnes & Greive, Clin Cosmet Investig Dermatol, 2018); complete corneocyte turnover takes approximately 40 to 56 days (Halprin, Br J Dermatol, 1972; Roberts & Marks, Arch Dermatol, 1980). Direct comparative studies of complete ceramide : cholesterol : fatty acid mimetic systems versus simple humectant or occlusive creams are rare and mostly manufacturer-funded, so the practical conclusion — replenish lipids and cleanse more gently — is better supported than any claim that a particular product category is superior. This is supportive care, not medical treatment.

Active ingredients that help repair the skin barrier

Four categories support barrier repair: lipids in an equimolar ratio (ceramides, cholesterol, free fatty acids), humectants (urea 3–10%, glycerin, panthenol), ceramide synthesis stimulators (niacinamide 2–5%) and gentle cleansing at pH 4.5–5.5.
Active ingredients provide building blocks; they cannot replace the skin's own biological processes. Lipid-mimicking formulations have the strongest supporting evidence.
A single-arm study with 30 participants (Spada 2018, without a placebo group) tested a cream containing ceramides, cholesterol, free fatty acids and glycerin in a ratio mimicking the natural lipid matrix, and recorded a short-term increase in hydration measured by corneometry of 49% after one hour and 47% after 24 hours; with twice-daily use for four weeks, TEWL fell by 17% (Spada, Barnes & Greive, Clin Cosmet Investig Dermatol, 2018).
Panthenol and the skin barrier: panthenol (provitamin B5) has a dual action. It works as a humectant and supports barrier repair. A randomised, vehicle-controlled study showed that, following SLS-induced barrier damage, a 5% dexpanthenol ointment led to a significantly faster reduction in TEWL and restoration of hydration compared with the vehicle over 7 days (n=25, p<0.05; Proksch et al., J Dermatolog Treat, 2017). Cosmetic concentrations of panthenol range from 0.5 to 10%.
Niacinamide (vitamin B3) has a particular role in barrier repair: rather than replenishing lipids directly, it stimulates their biosynthesis. Topical 2% niacinamide upregulates serine palmitoyltransferase, a key enzyme in ceramide biosynthesis, and increases ceramide production 4.1- to 5.5-fold in cultured keratinocytes (Tanno et al., Br J Dermatol, 2000). Caution is needed when extrapolating from keratinocyte cultures to in vivo TEWL — the effect size in human skin is less well quantified than in model data.
Urea acts in two ways depending on its concentration. At 3 to 10%, it is a humectant and NMF mimic; at 10 to 30%, it has a keratolytic action (Celleno 2018). Its mechanism at lower concentrations involves upregulation of aquaporin-3/9, keratinocyte differentiation and the antimicrobial peptides LL-37 and β-defensin-2.

Glycerin is a widely tolerated humectant and is often combined with ceramides and panthenol in barrier-supporting formulations.

What to avoid when your skin barrier is compromised

When the barrier is compromised, the rule is “less and gentler, not more and harsher”. Layering three exfoliants at once (AHA, BHA and retinoids together) increases TEWL and delays repair, so rather than stopping retinol completely when your barrier is compromised, reduce its frequency to 2 to 3× a week using the sandwich method (cream, retinol, cream). Hot water above 37 °C dissolves sebum faster and accelerates TEWL; lukewarm water is enough. Rough towels and mechanical friction cause microtrauma to the epidermis; the solution is to pat with a clean cotton towel or let the water evaporate. Scrubs containing plastic microbeads are no longer an option: Commission Regulation (EU) 2023/2055 banned intentionally added microplastics in rinse-off cosmetics from 17 October 2023 (EUR-Lex), so if you still have an old scrub at home, replace it. Frequent use of thick occlusive masks disrupts the microbiome over time; once a week is enough. If stinging, burning or redness persists for more than 2 weeks despite adjusting your routine, see a dermatologist.

At Dulcia: our approach to barrier repair

At Dulcia, we base barrier repair on Ceramide Complex CLR™ (0.1 to 1%) supplemented with panthenol (2 to 5%) and urea (3 to 10%), all within a routine with a pH close to that of the skin. For daily maintenance, choose our Moisturising Cream with Ceramides and, for an acutely compromised barrier, our Plus – First Aid for Hydration range.
For an acutely compromised barrier, we recommend a simple two-step repair routine — gentle cleansing followed immediately by a restorative formulation while the skin is still damp.

Frequently asked questions

How can I tell if my skin barrier is compromised?

The most common signs are tightness after washing, stinging when applying serums or active ingredients, flaking, redness in response to cold and wind, and an inability to retain hydration throughout the day. Subjective sensations only appear after several hours, during which TEWL rises without visible symptoms. If the feeling of tightness after washing persists even after applying moisturiser, the barrier is compromised and needs targeted repair.

How should I wash my face when my skin barrier is compromised?

Use lukewarm water (below 37 °C) and a cleanser with a pH of around 5.5 — a synthetic syndet or natural saponin-based gel — and avoid soaps with a pH of 9 or above. Pat your face with a clean cotton towel rather than rubbing it dry. Apply a restorative formulation while the skin is still damp, within 1 to 2 minutes of washing, when TEWL is temporarily at its highest. With a compromised barrier, single-step evening cleansing is enough unless you wear water-resistant SPF or heavy make-up.

How long does skin barrier repair take?

With targeted support from a lipid-mimicking formulation, improvements in barrier function are measured as increased hydration and reduced TEWL within 2 to 4 weeks (Spada 2018, single-arm measurement). Complete turnover of stratum corneum corneocytes takes approximately 40 to 56 days (Halprin 1972; Roberts & Marks 1980), but functional improvement precedes complete cell turnover. With repeated or severe disruption, recovery can take several months. Problems persisting for more than two months often involve eczema or another dermatological condition that requires a consultation with a dermatologist.

What pH should a cleanser have?

Between 4.5 and 5.5. The average pH of healthy skin is 4.7 (Lambers 2006). Soaps with a pH of 9 to 10 inhibit β-glucocerebrosidase and acid sphingomyelinase, the enzymes that process ceramides. After a single alkaline wash, pH returns to normal within hours. When choosing a cleanser, ask the manufacturer about its pH; if they do not disclose it, this is a warning sign.

Can I use retinol when my skin barrier is compromised?

Yes, but with adjustments. Reduce the frequency to 2 to 3× a week, apply using the sandwich method (cream, retinol, cream) and avoid combining it with AHA and BHA. In cases of acute irritation, stop for 2 to 3 weeks until TEWL returns to its baseline value. Retinol itself does not damage the barrier, but it increases cell turnover, worsening the lipid deficit in an already compromised barrier.

Do oil serums help repair the skin barrier?

Yes, as an additional occlusive layer. They do not replace lipid-mimicking formulations that replenish missing ceramides, cholesterol and free fatty acids in an equimolar ratio (Spada 2018). They work best in combination with humectants (panthenol, glycerin) and active ingredients that stimulate ceramide synthesis (niacinamide). Oil alone prevents water loss, but does not replenish what the barrier is missing.

Is dehydration the same as a compromised barrier?

No. Dehydration is a lack of water in the stratum corneum; a compromised barrier involves damage to the lipid matrix. Dehydration can exist without barrier damage (for example, during winter months when humidity is low). However, a compromised barrier almost always causes dehydration because TEWL increases and water escapes faster than the skin can replenish it. The approach therefore differs: dehydration calls for hydration, while a compromised barrier requires more comprehensive restoration using lipids, humectants and synthesis stimulators.

When should I see a dermatologist about a compromised skin barrier?

If redness, burning, flaking or inflammation persists for more than 2 weeks despite a gentle routine. These symptoms may indicate eczema, rosacea, seborrhoeic dermatitis or contact dermatitis — conditions that cosmetic skincare can support but not treat. A dermatologist can help distinguish between dysfunction that can be reversed with cosmetic care and a chronic condition requiring medication.

Conclusion

Skin regenerates itself when missing lipids are replenished and cleansing is gentler. Active ingredients support this process rather than replace it. If your barrier is acutely compromised and you would like to give it targeted support, try our Plus – First Aid for Hydration range.

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