Low pH Cleansers: Benefits and How to Choose One

• The acid mantle is a protective film on the outermost layer of skin, the stratum corneum
• This film is slightly acidic and can become dysfunctional if too alkaline or acidic  
• Low pH cleansers help maintain the balance of skin’s natural pH levels
• These cleansers can benefit all skin types, especially acne-prone and sensitive skin

Facial cleansers serve an important function in daily skin care routines by clearing away grime,  excess oils, debris and environmental impurities. Low pH cleansers offer an added benefit when  cleansing as they are formulated to restore and balance the stratum corneum, skin’s protective barrier.     

The stratum corneum, also known as the skin barrier, plays an important role in maintaining the health of skin; it keeps much-needed moisture in and harmful environmental elements out. When compromised, skin can develop uncomfortable symptoms such as inflammation, dryness, irritation and oversensitivity. 

What Is a Low pH Cleanser?

The pH scale refers to how basic or acid a substance is. It ranges from 0–14, with 0 being the most acidic and 14 the most alkaline.

The stratum corneum is the outermost layer of skin and as such, works to defend the inner layers of skin from harmful environmental bacteria and pathogens. Part of this layer includes the acid mantle, a thin protective film. 

As the name suggests, the acid mantle has a slightly acidic pH level, which creates an environment to prevent harmful bacteria and harmful microbes from proliferating.

At the same time, balanced acidity maintains the equilibrium of resident bacteria. This is the “good” bacteria that naturally exists on the skin’s surface and is part of the skin microbiome, an ecosystem that requires balance and stability to function properly and protect the body from pathogens. 

The microbiome, acid mantle and lipid barrier all work together to protect and maintain the balance of the skin barrier.

The general consensus is that skin’s pH is between 5.0 and 6.0. However, in a review of scientific data, one study determined that skin’s natural pH is below 5.0 and averages 4.7, so there are conflicting views on the specific number. 

A low pH cleanser is one that is formulated to be slightly acidic in order to be compatible with the skin’s natural pH level; under 5.5 and ideally between 4.0–5.0.

These cleansers effectively rid the skin of dirt, debris, dead skin cells and excess oils. They do so without causing an imbalance in the acid mantle and have a positive impact on how skin looks and feels.

Benefits of a Low pH Cleanser

A low pH cleanser plays an important role in maintaining the proper functioning of the skin barrier. Washing the skin with soap or just plain water can cause significant changes in skin’s acidity and damage the barrier function. Not only can this result in moisture loss, inflammation and irritation, it increases the risk of skin disorders.

Changes to the pH can contribute to the development of several inflammatory skin conditions such as contact dermatitis, atopic dermatitis and acne vulgaris; as well as Candida albicans fungal infections.

The skin’s surface is also home to skin flora, or microbiota which includes bacteria, fungi and viruses. These work in harmony with each other and the immune system to maintain skin health.

It has been demonstrated that an ideal environment for this bacterial flora is a pH of 4.0–4-4.5; an alkaline pH of 8.00–.9.00 will disperse this microbiota and instead encourage the proliferation of pathogenic bacteria, such as Staphylococcus aureus bacteria. 

A study examining pH levels in samples of soaps (including those for acne as well as other skin conditions), found that most had a pH level between 9.00 and 10.00 – well over the normal levels found in the acid mantle. 

Traditional soaps as well as other cleansers with a high pH can strip away the skin’s natural lipids which can disrupt the skin barrier, cause irritation and dryness, increase bacterial count and impact skin health; low pH cleansers maintain healthy skin by protecting from moisture loss and support the protective effects of the acid mantle and skin barrier.

How to Choose a Low pH Cleanser for Your Skin

While you will want to choose a cleanser that is as close as possible to your skin’s natural pH level, doing so can be challenging as not all products list the exact pH on their products. Most are labeled as low pH or pH balancing.

To ensure you are using an appropriate cleanser, one solution is to test your purchased product with pH testing strips. These are inexpensive, easily found in store and provide accurate results in seconds.  

All cleansers contain surfactants in order to effectively clear the skin of grime and debris, but  they also penetrate the skin barrier and can leave the skin feeling itchy, tight and red. 

To counteract these effects, it is vital to choose a cleanser that includes lipids, occlusives and humectants to replenish moisture and stabilize the skin barrier. 

Lastly, opt for a product that is free of fragrances, silicones, sodium-lauryl sulfate and dyes as these can all contribute to skin irritation. 

Dry skin

Dry skin requires a low ph cleanser that can provide an extra boost of moisture to keep skin healthy and comfortable. 

Hyaluronic acid is a humectant that is widely used in skin care products and is prized for its hydrating properties. It can attract and retain moisture which in turn plumps the skin and maintains elasticity. This acid is naturally present in the stratum corneum. 

Lipids are the skin’s natural fats; these strengthen the skin barrier and also protects the skin from absorbing harmful allergens and impurities. To preserve this function, look for a low pH cleanser that includes ceramides, a type of lipid that will reinforce the skin’s barrier and boost hydration.

Those with dry skin should avoid cleansers containing any antiseptic ingredients such as alcohol and witch hazel as these are not suitable for dry skin.

Oily skin

Oily skin would benefit from a low pH cleanser that contains exfoliative and oil-controlling properties. 

A cleanser containing niacinamide can target oiliness, and has been demonstrated to lower sebum (oil) production. This in turn can help tighten pores and improve texture – skin issues that are associated with oily skin.

Salicylic acid can loosen and break apart the bonds that hold skin cells together on the outer layer of skin to exfoliate debris and dead skin cells. It can also clear pores of excess oils and regulate oil production. 

Avoid cleansers with heavy formulations such as creams and lotions as these can block pores and cause the development of blackheads and whiteheads.  

Acne-prone skin

Acne-prone skin can be a sign of a compromised skin barrier, which can enable acne-causing bacteria to penetrate the skin. To help correct any imbalance, use a low pH cleanser to support your skin’s natural defenses and opt for one that has active ingredients to target acne. 

Acne-prone skin is typically characterized by blocked pores containing debris, excess oils and bacteria. Acne lesions may be noninflammatory (whiteheads and blackheads) or inflammatory papules, pustules or cysts.

As acne is notoriously difficult to treat, choosing a product with several active ingredients can often produce better results. 

Opt for a cleanser that contains a potent antibacterial agent such as benzoyl peroxide to clear blocked pores and kill bacteria. Salicylic acid is also a good choice, not only for its exfoliative properties but because it can effectively clear blackheads.

Glycolic acid can also clear blocked pores by sloughing off dead skin cells and eliminating excess oils. Like hyaluronic acid, it is also a humectant, and can draw in and retain moisture to the stratum corneum.    

Avoid any cleansers that contain coconut or mineral oil, which will likely block pores and worsen acne symptoms.

Sensitive skin

An imbalanced skin pH can cause red, sensitive skin that flakes, stings and itches, and is vulnerable to skin conditions such as atopic dermatitis. A gentle low pH cleanser can help balance pH levels and protect your skin from irritants.

Shea butter has potent anti-inflammatory and antioxidant properties to reduce inflammation and ease irritation. This is a gentle ingredient that is high in fatty acids to help soothe, soften and condition skin.

Glycerin is another effective option for sensitive skin. It is naturally found in the stratum corneum and acts as a humectant to moisturize skin. Glycerin also helps maintain elasticity, protects the skin barrier and can facilitate barrier repair.     

Those with sensitive skin should take special care to avoid additives such as fragrances, sodium-lauryl sulfates and dyes, as these can all contribute to exacerbating sensitivities. 

Should You Use a Low pH Cleanser?

Yes, you should. A low pH cleanser is ideal for all skin types as it maintains the integrity of the skin barrier. Doing so is especially important for those who experience acne, eczema or skin irritation in the form of itchy, dry red skin. This is an indication that the barrier is weakened or damaged and that pH levels are not optimal.

A low pH cleanser can remove dirt and debris, and refresh skin. It can help maintain skin’s natural pH level, strengthen the skin barrier and reduce or eliminate uncomfortable symptoms with continued use. 

Takeaway

The stratum corneum is composed of the microbiome, acid mantle and lipid barrier which all work in harmony to form a protective outer layer on the body.

The acid mantle is a film that is slightly acidic and can become dysfunctional if too alkaline or acidic. This imbalance can lead to a number of conditions including sensitivity and dryness; acne and atopic dermatitis.

Low pH cleansers can gently cleanse the skin, balance the skin’s natural pH level and strengthen the skin barrier function. 

For best results, opt for a product that is formulated for your skin type. Dry skin would benefit from hyaluronic acid and ceramides to boost moisture; for oily skin, salicylic acid and niacinamide to reduce oiliness and exfoliate; acne would benefit from antibacterial and oil-controlling ingredients; sensitive skin, shea butter and glycerine to soothe irritation and soften skin. 

For any skin type, it is important to choose a product that includes lipids, occlusives and humectants to counteract the drying effects of the cleanser and to stabilize the skin barrier.