We have all heard about AHA. In the 70s, the skincare benefits of AHA, such as exfoliation, skin smoothing, and antiaging properties, were discovered by Drs. Van Scott and Ruey Yu. Fast forward to 2026, the new beauty buzzword is PHA. PHA is a new generation of AHAs that has been clinically proven to deliver better skin benefits as compared to AHA, and without the side effects that are associated with AHA. In fact, PHAs have been found to be compatible with clinically sensitive skin, including rosacea and eczema, and can be used after medical aesthetic procedures.
Polyhydroxy acids (PHA) are increasingly recognised as a cornerstone in modern medical-grade skin treatments. From professional peel systems targeting acne, pigmentation, and fine lines, to advanced facials designed for sensitive skin, PHA offers a unique combination of controlled exfoliation, hydration, and barrier support.
What Is PHA?
PHA, or polyhydroxy acid, is a sugar-derived chemical exfoliant. It is structurally similar to alpha hydroxy acids (AHA) but features a larger molecular size. Common PHAs include lactobionic acid and gluconolactone, both of which have been used in professional skincare for their gentle yet effective properties.
Because of their larger molecular structure, PHAs penetrate the skin slowly and superficially. This results in controlled exfoliation with minimal irritation, making them ideal for sensitive or reactive skin. Unlike smaller-molecule acids, PHAs renew the skin without causing stinging, visible peeling, or compromising skin barrier protection.
Additionally, PHAs also act as humectants, attracting and binding water to the outer layers of the skin. This dual action of exfoliation and hydration enhances our skin’s stratum corneum barrier function, therefore increasing the skin's natural immunity. These significantly distinguish PHAs from other chemical exfoliants.
Where Do PHAs Come From?
PHAs are naturally derived from sugars. For example:
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Lactobionic acid comes from lactose, the sugar found in milk.
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Gluconolactone is derived from glucose.
These sugar-derived acids are processed into stable, skin-safe forms for professional use. Their natural origin contributes to their excellent tolerability and makes them suitable for sensitive or compromised skin.
Because of their humectant properties, PHAs also provide hydration while exfoliating. This is particularly valuable in medical-grade peel systems where maintaining barrier integrity is essential for optimal results.
PHA vs AHA vs BHA
Alpha hydroxy acids (AHAs), beta hydroxy acids (BHAs), and polyhydroxy acids (PHAs) are types of acids commonly found in chemical exfoliants. These acids help remove dead skin cells from the skin's surface, but they function in different ways and each has its own unique benefits.
Alpha Hydroxy Acids (AHA)
AHAs, such as glycolic acid and lactic acid, are water-soluble acids that primarily work on the surface layer of the skin. They improve texture, dullness, pigmentation, and fine lines by dissolving dead skin cells. Due to their small molecular size, AHAs penetrate quickly and deeply, which can increase the risk of irritation, especially in sensitive or reactive skin.
Beta Hydroxy Acid (BHA)
Salicylic acid is the most common form of BHA. It is oil-soluble, allowing it to penetrate into pores and dissolve excess sebum and debris. BHAs contain antibacterial properties, making it highly effective for acne-prone and congested skin, but can be drying if overused.
Polyhydroxy Acid (PHA)
PHA differs from both in several ways:
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Larger molecular structure for slower, controlled penetration
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Gentle exfoliation suitable for sensitive skin
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Humectant properties that enhance hydration
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Antioxidant activity to neutralise free radicals
While AHA addresses surface texture and BHA targets oil and congestion, PHA provides gentle exfoliation while simultaneously hydrating the skin and reinforcing the skin barrier.
How PHA Works in the Skin
PHA works by breaking down the adhesive protein complexes that acts like a glue to hold down dead skin onto the surface of our skin. This “controlled exfoliation” allows effective shedding of older cells to improve skin texture, even out skin tone and reduces fine lines and wrinkles.
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Texture improvement: Skin feels smoother and looks more refined.
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Tone enhancement: Uneven patches and dullness are gradually reduced.
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Fine line reduction: Surface irregularities are smoothed, softening the appearance of wrinkles.
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Acne support: PHA helps prevent clogged pores, reducing the risk of breakouts.
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Enhanced product absorption: Skincare ingredients penetrate more effectively.
PHA also works like a natural humectant to attract and retain moisture in the outer layers of the skin. This maintains hydration during exfoliation, preventing the dryness and irritation that can result from other acids. Additionally, lactobionic acid, a form of PHA, has antioxidant properties, protecting skin from oxidative stress caused by UV exposure and environmental factors, which are key contributors to ageing and hyperpigmentation.
PHA and the Skin Barrier
The skin barrier is the outermost layer of the epidermis that protects against water loss, environmental stress, and microbial invasion. Skin barrier or epidermal barrier refers to the ability of the epidermis, especially the stratum corneum (SC), to protect the skin from environmental stressors, hormonal imbalances, cellular metabolism and even genetic influences. It regulates and maintains Natural Moisturising Factors (NMF)and balance in order to sustain healthy skin elasticity and cellular metabolism. A strong barrier is essential for healthy, resilient skin.
When the barrier is compromised:
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Moisture retention decreases
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Inflammation increases
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Skin becomes more reactive and sensitive
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Acne and pigmentation are more likely to worsen
Many exfoliating treatments improve surface appearance but risk weakening the barrier. PHA is different. Its gentle penetration and hydrating properties preserve the barrier while allowing exfoliation and renewal.
For acne, pigmentation, and anti-ageing treatments, barrier preservation is crucial. It allows the skin to respond positively to treatment, reduces recovery time, and prevents the recurrence of inflammation.
Why Skin Barrier Health Is Important
One does not build a house before investigating the soil and creating a strong structural design in order to reinforce the ground with a strong foundation.
With the emergence of new treatment options and numerous claims on efficacy, many people are naturally more inclined to make their decisions for skin problems using the most recent beauty trends. The rapid expansion of skin care choices throughout time has made it possible to incorporate optimal skin care as a crucial part of post-procedural and a part of the treatment plan. However, many have forgotten the age-old adage that we must "learn how to walk before we run". Without healthy skin barrier functions, it is little wonder many found their anti-ageing, pigmentation and acne treatments ineffective.
Compromised skin barrier causes dysregulation of our skin barrier functions. Clinical studies have shown that these deficiencies are observed in a variety of skin conditions such as acne, hyperpigmentation, eczema and premature ageing. Maintaining healthy skin and effectively managing various skin conditions are much more challenging without a resilient skin barrier. The integrity of the skin barrier directly affects treatment outcomes. When the barrier is healthy:
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Moisture levels remain stable, reducing dryness and irritation
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Inflammatory responses are controlled, limiting pigmentation triggers
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Collagen synthesis and cellular repair occur more efficiently
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The skin is more resilient to environmental stressors
Compromised barriers lead to slower healing, increased sensitivity, and higher susceptibility to breakouts, hyperpigmentation, and accelerated ageing. Professional treatments that maintain barrier health — such as those using PHA — achieve results that are both visible and sustainable.
Why Choose PHA
PHAs improve the skin barrier functions, which is particularly beneficial for those who have problem skin. Furthermore, because of their polyhydroxy composition, they act as humectants and moisturisers while also neutralised harmful oxidative stress. PHAs contain free radical scavenging properties and do not cause photo-sensitivity. PHAs also have the added benefit of suppressing matrix metalloproteinase (MMP) enzymes, which are one of the major contributing factors of premature ageing.
Advanced skin therapies with PHA allow treatments to deliver noticeable improvements without causing excessive peeling or downtime. This makes it an ideal choice for those seeking professional-grade treatments with minimal disruption to their daily routine.
Who Is PHA Suitable For?
PHA is suitable for a wide range of individuals:
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Sensitive or reactive skin
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Acne-prone skin
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Pigmentation concerns such as melasma or post-inflammatory hyperpigmentation
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Early signs of ageing, including fine lines and loss of elasticity
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Dehydrated or dull skin
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Individuals new to chemical exfoliation
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Those undergoing combination acid treatments, where PHA helps buffer stronger acids and maintain tolerance
Its mild profile makes it an excellent option for maintenance treatments, as well as for professional peel systems designed to address acne, pigmentation, or ageing concerns.
Who Should Avoid PHA?
While generally well-tolerated, PHA may not be appropriate for:
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Individuals with active skin infections or open wounds
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Those who are currently on isotretinoin (Accutane) therapy
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Pregnant or breastfeeding women without medical clearance
Consultation with a trained professional is essential to ensure safety and optimal results.
Why PHA Is Included in Advanced Peel Systems
PHA aids in pore clarification and inflammation reduction in professional acne treatments while preserving barrier integrity and hydration. It ensures uniform cellular turnover and enhances the efficacy of skin brightening active ingredients in pigmentation treatments. It improves firmness and elasticity in anti-ageing therapies by retaining moisture, smoothing texture, and promoting collagen formation.
PHA represents a shift toward intelligent skin renewal. It supports exfoliation while maintaining barrier health, hydration, and resilience.