If the word acid makes you think of stinging, peeling, or hiding indoors while your skin recovers—meet gluconolactone. This gentle exfoliating ingredient is proof that acids don’t have to be harsh to be effective.

Gluconolactone is a naturally occurring compound in the body, closely related to glucose (a simple sugar). It’s also found in nature in things like fruits and honey, and it’s commonly used in food science to enhance flavour and stability. In other words, it’s a molecule your body already knows well.

In skincare, gluconolactone has earned its reputation as one of the most skin-friendly exfoliating acids out there. It smooths, brightens, hydrates, and supports the skin barrier—all without the drama.

Other names: PHA/Polyhydroxy acid (one of a few acids under this umbrella term)

What it is: Exfoliating, humectant, barrier supporting

You can find it in: Hydratone

What makes gluconolactone (PHA) a great skincare ingredient?

Gluconolactone belongs to a family of exfoliating acids called polyhydroxy acids (PHAs). Like other hydroxy acids, PHAs help remove dead skin cells from the surface of the skin. What sets them apart is how they do it.

In skincare, exfoliating acids are generally grouped into three categories:

• AHAs (alpha hydroxy acids)
• BHAs (beta hydroxy acids)
• PHAs (polyhydroxy acids)

Alpha Hydroxy Acids

AHAs, such as glycolic and lactic acid, are water-soluble acids that work on the skin’s surface. They exfoliate by loosening the bonds between dead skin cells, revealing fresher skin underneath. While effective, AHAs—especially glycolic acid—can be quite strong, and depending on concentration, are often recommended for limited weekly use due to their potential to irritate the skin.

Beta Hydroxy Acids

BHAs, most notably salicylic acid, are oil-soluble. This allows them to penetrate into pores and break down oil and debris, which is why they’re often recommended for acne-prone skin or conditions like keratosis pilaris.

Polyhydroxy Acids

PHAs, like gluconolactone, are often described as the next generation of AHAs. Structurally, they are similar—but they have larger molecules and additional hydroxyl groups, which fundamentally change how they interact with skin. Instead of penetrating quickly and deeply—which is often the reason irritation occurs with chemical exfoliants—PHAs stay closer to the surface, exfoliating more slowly while simultaneously attracting water. This makes them particularly well suited for sensitive or reactive skin.

In short: PHAs deliver the benefits of exfoliation, with a much gentler touch.

Part of what makes gluconolactone in particular so well tolerated is that it doesn’t just exfoliate—it also has soothing and antioxidant properties, which help calm the skin during the exfoliation process. That said, it’s still an active exfoliant, and patch testing is always recommended.

Gluconolactone brightens and improves uneven tone and texture

Gluconolactone works by helping skin shed dead cells more efficiently. Like AHAs, it loosens the bonds that hold old skin cells together, encouraging them to release in a more uniform way. When dead cells don’t linger on the surface, skin appears smoother, more even, and brighter.

What makes gluconolactone different is its larger molecular size. Because it penetrates the skin more slowly, it delivers exfoliation without the sharp spike in irritation often associated with stronger acids like glycolic or lactic acid³. This means you get visible improvements in texture and tone, all while having a much lower chance of experiencing redness, burning, or barrier disruption.

Dullness often comes from retention hyperkeratosis, where old skin cells linger on the surface and scatter light unevenly. When light doesn’t reflect smoothly, skin can look flat or tired. Dull skin isn’t always as obvious as a pimple or a dark spot—a lot of people will get the sense that their skin doesn’t look as healthy overall but can’t quite put their finger on it. The usual culprit is dull skin.

By encouraging steady exfoliation, gluconolactone helps reveal newer skin cells underneath—cells that have a smoother surface and reflect light more evenly. This naturally enhances skin’s radiance and makes it look and feel brighter and healthier.

Gluconolactone refines pores and reduces rough patches

Pores tend to look larger when they’re clogged with excess sebum, dead skin cells, and keratin. When this buildup collects around the opening of the pore, it stretches the surrounding skin and makes pores more noticeable.

Gluconolactone helps by gently encouraging dead skin cells to shed more evenly. It weakens tiny protein structures in the outer layer of skin that hold dead cells together, allowing them to release before they accumulate around pores.

By keeping the surface of the skin clearer and more balanced, gluconolactone helps pores appear smaller and more refined over time—not by shrinking them (that technically isn’t even possible as pore size is genetic!) but by keeping them from becoming congested in the first place.

Rough or bumpy skin is often the result of similar culprits—excess sebum, dead skin cells, and keratin. It can be why your skin looks particularly textured after a long day as these natural parts of our skin accumulate over time.

Gluconolactone gently promotes a healthier shedding process by influencing how skin cells detach from one another. It binds to calcium ions in the epidermis—minerals that play a role in keeping skin cells tightly connected—and helps loosen those connections just enough to allow smoother turnover³.

Because gluconolactone penetrates slowly and stays near the surface, this exfoliation is controlled and gradual. The result is smoother skin without triggering irritation, sensitivity, or barrier damage.

With consistent use, gluconolactone helps refine pores, soften rough patches, and promote a clearer, more radiant complexion—without the peeling or flaking that can make exfoliation feel like a trade-off.

Gluconolactone helps your skin maintain its moisture level

Gluconolactone isn’t just an exfoliant—it’s also a humectant.

Humectants are ingredients that attract and bind water, helping increase the skin’s moisture content and improve softness and flexibility. 

Beyond hydration, gluconolactone has been shown to support the skin barrier. A strong barrier helps prevent excess moisture loss while defending against external stressors like pollution, irritants, and acne-causing bacteria. When the barrier is healthy, skin is more resilient, comfortable, and balanced overall.

P.S. The skin barrier is becoming a buzz word in skincare. You’ve probably heard products marketed as “barrier repair”—this isn’t just another way to grab your attention. Your skin barrier is a vital component to your skin’s health. Learn all about it here.

Gluconolactone supports healthy aging and defends your skin against collagen and elastin loss

Healthy-looking skin is less about “turning back the clock” and more about supporting the structures that keep skin strong, comfortable, and luminous over time. Gluconolactone plays a supportive role in this process by helping protect collagen and elastin—the proteins responsible for skin’s firmness and flexibility.

One natural process that can affect these proteins over time is glycation. In simple terms, glycation happens when sugars attach to proteins like collagen, making them stiffer and less flexible. As this process continues, skin can lose some of its natural bounce and radiance. Supporting skin against glycation is considered an important part of maintaining skin health as it matures.

Polyhydroxy acids like gluconolactone have been shown to help limit glycation-related damage, supporting collagen and elastin so skin can remain more resilient and supple over time. Rather than aggressively stimulating the skin, gluconolactone works in a gentle, skin-respecting way that aligns well with our emphasis on skin longevity.

Gluconolactone also supports healthy aging by encouraging steady skin renewal. In clinical research, a formulation containing 2% gluconolactone supported gentle surface cell turnover, without causing irritation.

Finally, gluconolactone offers antioxidant support, helping reduce the impact of oxidative stress—one of the key factors that can weaken collagen over time. Together, these benefits make gluconolactone a quiet but powerful ally for skin longevity, helping skin look vibrant, supported, and comfortable at every age and every stage.

Who is gluconolactone (PHA) good for?

Gluconolactone is a particularly good fit for:

• Sensitive skin: gentle, low-irritation exfoliation can make reactions less likely to occur
• Dry or dehydrated skin: offers strong moisture-binding and barrier-supporting properties
• Mature skin: support elasticity, brightness, and skin longevity
• Skincare beginners: offers the benefits of exfoliation without overwhelming their skin

It’s an ideal introduction to active skincare—effective, forgiving, and skin-friendly.

Gluconolactone (PHA) in Hydratone

Gluconolactone plays a central role in Hydratone, our hydrating, exfoliating essence designed to support smooth, comfortable, and balanced skin.

In this formula, gluconolactone was chosen for its ability to gently refine skin texture while remaining suitable for frequent use. It helps keep the skin surface clear and even, without the redness or tightness that can come with stronger exfoliating acids.

Because gluconolactone also supports hydration and skin comfort, it fits naturally into Hydratone’s 3-in-1 approach—toning, exfoliating, and hydrating in a single step. The result is skin that feels refreshed and refined, yet calm and well supported.

Shop Hydratone here.

Summary

Gluconolactone:

• Gently exfoliates to improve skin texture and tone
• Helps refine the look of pores by keeping the skin surface clear
• Smooths rough patches with less likelihood of irritation, peeling, or redness
• Attracts moisture to support hydration and skin comfort
• Helps maintain a strong skin barrier for healthier-looking skin
• Supports skin longevity and healthy aging
• Is well suited for sensitive skin and for regular use (depending on the concentration)
• Can be found in Hydratone, a 3-in-1 toning, exfoliating, and hydrating essence

At the end of the day, gluconolactone is the kind of ingredient that shows up, does its job gently, and leaves your skin feeling smooth, comfortable, and quietly happy—no drama required 💜

Want more ingredient insights? Read our longform articles here, or check out our ingredient database for short and sweet breakdowns.