There’s a (relatively) new chemical exfoliant in town – PHA (poly hydroxy acid) gluconolactone! It’s no secret that we love our AHAs (alpha hydroxy acid). These chemical exfoliants are tried and true ingredients, and we’re big proponents of them being used as staples in anyone’s routine to tackle anything from dry skin to wrinkles. That said, the gold standard AHA glycolic acid is not really made for everyone. For many people, glycolic acid may simply be too aggressive, leading to irritation, redness, and increased sensitivity. Enter PHA gluconolactone! Gluconolactone is claimed as the sensitive skin savior here to deliver all of glycolic acid’s benefits without the skin irritation. But does it work? In this guide, we dive into just what is gluconolactone, what benefits gluconolactone brings in skincare, if it’s really comparable to glycolic acid, and whether or not you should look for a gluconolactone toner on your next Sephora trip.
What is Gluconolactone?
Chemical exfoliants are an effective staple in many people’s routine. However, since these can also easily cause skin irritation, chemists and researchers have looked into potential alternative solutions. Enter poly hydroxy acid! This a much larger molecule in size that can potentially bring the same level of benefits without the irritation. In skincare, there are two main PHAs: gluconolactone and lactobionic acid. Between the two, gluconolactone is much easier to find in a variety of products and also has more clinical evidence.
Gluconolactone is a naturally occurring compound that is closely related to the simple sugar, glucose. In fact, it is a product of glucose oxidase, an antibacterial enzyme found in many species of fungi. Gluconolactone can also be found in many fruits, honey, and even wine. It’s such a prevalent molecule, it actually has many applications in food science such as enhancing flavor. But what does the clinical evidence say about gluconolactone’s skin benefits?
Gluconolactone Benefits in Skincare
In skincare, gluconolactone is touted as not just a gentle exfoliator, but also a hydrator and even antioxidant.
Gluconolactone as a Gentle Exfoliator
First and foremost, gluconolactone is a gentle chemical exfoliant that can speed over skin’s cell turnover rate. Remember, this is important in maintaining skin’s major cell functions and looking its absolute best. In one particular study, study participants stained their skin with a dye that would penetrate the deeper layers of skin. They then applied creams with various AHA- and PHA-containing creams to see if these products help expedite dye removal, signifying faster cell turnover. They found that the cream with 2% gluconolactone was successfully able to speed up cell turnover.
Unfortunately, there isn’t a study that directly compares gluconolactone to classic glycolic acid (yet). While we can’t say the two can give you comparable benefits, it is helpful to know that there is clinical evidence showing that gluconolactone does in fact work as an exfoliator despite its much bigger size.
Gluconolactone as a Hydrator
Both PHAs, gluconolactone and lactobionic acid, have also been looked at for “hydrating” benefits. In one small (n=16) study, researchers compared a 10% gluconolactone peel to a 30% gluconolactone peel over 4 weeks and found that both were effective in decreasing TEWL (transepidermal water loss) as well as reducing sebum level. Though this study is small, it does showcase gluconolactone’s potential as a great ingredient for those with oily skin to keep skin hydrated while keeping sebum production in check.
Gluconolactone vs. Acne
Though you won’t really see too many products directly talk about gluconolactone as an acne superstar, one of the most interesting gluconolactone clinical studies happens to be in the acne realm. In a study with 150 participants, a topical with a whopping 14% gluconolactone was tested against a placebo group and a group using 5% benzoyl peroxide for 12 weeks. By the end of 12 weeks, both the 5% benzoyl peroxide group and the 14% gluconolactone group significantly decreased the total number of lesions compared to the placebo. Interestingly, though overall performance with benzoyl peroxide was better, gluconolactone was on par with benzoyl peroxide in specifically decreasing the number of inflammatory lesions. This is actually fairly impressive & surprising since 5% BPO is an OTC acne drug that has been through countless large studies!
If you dive deeper into the rabbit hole, you might find that gluconolactone is also linked with other beneficial properties such as being an antioxidant or an anti-aging helper. However, the data there is too early for us to have any meaningful conclusions here.
In summary, gluconolactone has about… one to two interesting studies per claimed skin benefit, which feels a bit sparse. But! As chemists, we can tell you that fantastic data is difficult to come by. The amount of clinical testing available on gluconolactone makes this ingredient, in our humble opinion, worthy of a try, especially if you have oily, sensitive skin.
Shopping Guide: Do I Get the PHA Gluconolactone Toner, Serum, or Mask?
Ultimately, if you’re perfectly happy with your glycolic acid product, there isn’t a lot of reason to switch to gluconolactone. However, if you’ve been burned (hopefully not literally) by the chemical exfoliant category before, have oily/sensitive skin, or just looking for something more gentle to go with the other aggressive actives in your routine – gluconolactone may be the way to go.
Like AHAs, exfoliating toners that contain PHA gluconolactone may be a great place to start for the absolute beginner. However, given that most of gluconolactone clinicals are tested at fairly high percentages, you might want to look for something that gluconolactone at a much higher level.
Regardless of what product types you go for, this is where we would recommend products with transparent percentages. In a daily toner, 2% to 10% is ideal. For a more leveled up experience, consider a higher dose serum with >10%. Last but not least, you can get the most out gluconolactone with a high level weekly peel at >30%.
If you’re looking for a starting place, here are a few products to consider:
- For the most sensitive skin type: The Inkey List PHA Toner 3% Gluconolactone
- Basic daily maintenance: Innisfree Green Tea Enzyme 7% PHA Gentle Exoliating Toner
- Level up slightly: Ole Henriksen Dewtopia 20% Acid Night Treatment
- Max efficacy for even sensitive skin: Chemist Confessions Baby Steps 30% gluconolactone 15% lactic acid
Conclusion
Although compared to glycolic acid, the clinical data behind gluconolactone isn’t as abundant, there are still quite a few interesting, noteworthy clinical studies. It is a great gentle exfoliator with hydration and even potentially sebum-normalizing capabilities, making gluconolactone a great ingredient for those with an oily, sensitive skin type. This is a high use level active ingredient where you would want to target at least 2% to 7% daily, and 20%+ for more efficacious treatments.
References
Edison, B. L., Smith, H. A., Green, B. A., & Tierney, N. K. (2021). 27887 Skin exfoliation with low concentrations of alpha hydroxy acids and poly hydroxy acids when incorporated into wash-off or leave-on products using a novel abbreviated model to measure cell turnover rate. Journal of the American Academy of Dermatology, 85(3), AB165.
Hunt, M. J., & Barnetson, R. S. (1992). A comparative study of gluconolactone versus benzoyl peroxide in the treatment of acne. Australasian journal of dermatology, 33(3), 131-134.
Wulaningsih, T. I. (2023). Gluconolactone in Cosmetic. KESANS: International Journal of Health and Science, 2(9), 730-745.
Jarząbek‐Perz, Sylwia, Marta Dziedzic, Helena Rotsztejn, and Anna Kołodziejczak. "Evaluation of the effects of 10% and 30% gluconolactone chemical peel on sebum, pH, and TEWL." Journal of Cosmetic Dermatology 22, no. 12 (2023): 3305-3312.
