Evidence suggests the skin's natural surface pH is lower than commonly cited and everyday cleansing habits may be quietly disrupting this balance, making skin duller, inflamed and more prone to ageing.
This blog covers:
- Skin microbiome and the pH factor
- How to protect your skin's natural microbiome (expensive postbiotics are not the solution!)
- The worst cleansers for skin barrier health
- Skin pH and the link to skin diseases
- Simple ways to support skin barrier health (no expensive gimmicks)
Image: your skin's natural pH determines your glow.
Struggling with a damaged skin barrier, a disrupted microbiome or skin that just won't glow no matter what you apply? The answer may lie in something most skincare routines overlook entirely: your skin's pH.
The skin microbiome and the pH factor
Healthy skin has a naturally acidic pH around 4.5–5.0 when undisturbed by tap water or skincare (Lambers, 2006). Remember this pH: 4.5–5.0, as it's important for your skin.
This is known as the acid mantle, your skin's first line of defence, meaning it helps to keep bad bacteria, dust mites and other baddies out.
The acid mantle also supports the skin's natural microbiome, which is an important part of this defence system, offering antibacterial protection (Li, 2023; Lambers, 2006). Even a small rise in skin pH can disrupt the biome's defences, causing the biome to dislodge (Lambers, 2006). A pH range above 5.5 also adversely affects skin cell shedding and may trigger inflammation, which can leave skin looking dull, dry, irritated and even prematurely aged (Li, 2023; Hatano, 2009).
Diagram: The Acid Mantle and Skin Microbiome. A thin, naturally acidic film called the acid mantle sits on top of the skin barrier, helping beneficial bacteria adhere to the skin and protect skin against irritants, bacteria, dust mites and infection. Healthy skin typically sits at a pH of 4.5–5.0 when not adversely affected by tap water, cleansing and skincare.
Skin pH and the link to skin diseases
Increased skin pH is linked to inflammatory skin conditions, including eczema, dermatitis, ichthyosis, rosacea, acne and elderly, aged or dry skin (Proksch, 2018).
- Skin affected by eczema typically has an elevated pH of 5.5–6.5 (Rippke, 2004)
- The higher the pH, the worse eczema tends to present (Eberlein-König, 2000).
- Swallowing probiotics or adding postbiotics to a skin cream or cleanser will not fix a pH-damaged microbiome.
Diagram: The Missing Acid Mantle and Dislodged Skin Microbiome. Elevated skin pH (5.5 and above) is commonly seen in eczema-prone skin, acne, dermatitis and other skin rashes, as well as elderly and ageing skin. An elevated or alkaline pH can disrupt both the microbiome and the skin's protective barrier. Skin appears drier and cracks can appear. There is an increased risk of staph infections and dust mite allergy.
The worst cleansers for skin barrier health
Tap water, soap and many cleansing products have a higher (more alkaline) pH than healthy skin, and they can raise skin surface pH above 7.5 after washing (Lambers, 2006; Brooks, 2025).
Image: soap and regular cleansing habits could be your skin's worst enemy.
While skin pH typically returns to its natural baseline within a few hours, this recovery window matters (a lot!), as repeated daily exposure can disrupt the skin's barrier and microbiome before it has the chance to recover, which over time may affect skin's resilience, hydration and natural glow. The result is dryer, dull and more aged skin.
Image: Liquid soaps and foam cleansers can also have a high pH which can damage the skin barrier and biome. Always check the pH of your cleansing products, and ask the manufacturer for the exact pH if it's not listed on the bottle or product page.
How to protect your skin's natural microbiome
Healthy skin begins with protecting the natural pH (your acid mantle), and it's really simple.
Switching to low pH skincare can naturally reduce inflammation, support the acid mantle, promote skin cell turnover and boost collagen and ceramide production for smoother, younger-looking skin and radiance (Narda, 2021; Hatano, 2009).
Q: Do all skincare products have a pH?
No. A sufficient water content is required for pH to be measurable, so ointments, balms, oils and products containing small amounts of water do not have a pH. These can still support the skin in other ways — for example, by forming a protective layer over the skin — but they won't actively correct an elevated skin pH the way a properly formulated low-pH moisturiser can.
Q: Is 'pH balanced' skincare the same as low pH?
No. The term 'pH balanced' is not standardised in the skincare industry, and may reflect an outdated reference range of pH 5.5–6.0, which is the same pH seen in eczema and aged skin (Blaak, 2011).
In other words, a product labelled "pH balanced" could actually encourage an unhealthy skin pH. A study demonstrated that skincare with pH 5.5 and above, often called pH balanced, can elevate skin beyond 5.5 into a range seen in elderly and damaged skin and this may impair barrier function, reduce ceramide production and promote rashes and premature skin ageing (Blaak, 2011; Hatano, 2009).
Simple ways to support skin barrier health (no expensive gimmicks)
A simple switch to low-pH skincare with gentle biome-friendly ingredients may be one of the most effective ways to restore your skin barrier and promote a more youthful glow.
Low pH skincare within pH 4.0–5.0 may:
- Promote natural skin cell turnover → glow and radiance (Hatano, 2009; Danby, 2023)
- Increase lipids, hydration and ceramides naturally → smoother skin (Hatano, 2009)
- Reduce inflammation → more even skin tone and calmer skin (Hatano, 2009)
Our low pH skincare includes Eczema Friend, 24-Hour Rescue and Natural Gentle Cleanser. Formulated at a low pH between 4.5–4.7, mirroring the skin's natural acid mantle, they gently support biome and barrier health and promote skin radiance, naturally.
References: Lambers H, et al. Natural skin surface pH is on average below 5, which is beneficial for its resident flora. Int J Cosmet Sci. 2006. Li R, et al. Association between skin acid mantle, natural moisturizing factors, and antibacterial activity against S. aureus. Clin Cosmet Investig Dermatol. 2023. Hatano Y, et al. Maintenance of an acidic stratum corneum prevents emergence of murine atopic dermatitis. J Invest Dermatol. 2009. Proksch E. pH in nature, humans and skin. J Dermatol. 2018. Rippke F, et al. Stratum corneum pH in atopic dermatitis: impact on skin barrier function and colonization with Staphylococcus aureus. Am J Clin Dermatol. 2004. Eberlein-König B, et al. Skin surface pH, stratum corneum hydration, transepidermal water loss and skin roughness related to atopic eczema and skin dryness. Acta Derm Venereol. 2000. Narda M, et al. Glycolic acid adjusted to pH 4 stimulates collagen production and epidermal renewal. J Cosmet Dermatol. 2021. Brooks SG, et al. The skin acid mantle: an update on skin pH. J Invest Dermatol. 2025. Blaak J, et al. Treatment of aged skin with a pH 4 skin care product normalises increased skin surface pH and improves barrier function. J Cosmet Dermatol Sci Appl. 2011.
