PHA (Gluconolactone)
INCI · Gluconolactone · also PHA
How it works
Gluconolactone belongs to the polyhydroxy acid (PHA) family, and I think of it as the AHA family's gentler cousin. Its molecule is significantly larger than glycolic or lactic acid, which slows penetration into the skin and means it exfoliates the surface layer without diving as deep or as fast — this is the whole reason it's so much better tolerated.
Beyond loosening the bonds between dead skin cells, gluconolactone is also a humectant and antioxidant, drawing in moisture while helping to neutralize free radical damage, which makes it feel more like a hydrating treatment than a harsh peel. It also has chelating properties, binding metal ions that can otherwise catalyze oxidative damage in formulations and on skin.
The evidence
Clinical studies on PHAs, including gluconolactone specifically, show improvements in skin texture, tone, and hydration with significantly less stinging and erythema than reported with equivalent AHA concentrations. It's also been studied for its usefulness in rosacea and sensitive skin populations who typically cannot tolerate glycolic acid at all, and some formulations combine it with soothing agents to further reduce any residual risk of irritation.
Suitability
- Sensitive and rosacea-prone skin: often the only exfoliating acid these patients can tolerate
- Dry skin: the humectant properties add hydration while still exfoliating
- Acne-prone skin: gentle enough for regular use without over-stripping
- Anyone new to chemical exfoliation: a low-risk starting point
Concentration
Most formulas range from 4% to 10%; I don't hesitate to recommend nightly use even at the higher end for most patients, given its excellent tolerability. Those transitioning from no exfoliation at all should still start a few times a week before going daily, watching for any unexpected sensitivity.
Conflicts & combinations
- Pairs well with hyaluronic acid and panthenol for a hydrating exfoliation routine
- Can be layered with ceramide-containing moisturizers without concern
- Generally safe to combine with retinoids, though I still stagger nights for very reactive skin
- A good bridge ingredient for patients wanting to eventually tolerate stronger AHAs
- Effective from
- 5%
- Max safe
- 10%
What is gluconolactone used for?
It's a PHA exfoliant that smooths texture and brightens dullness while hydrating the skin, with minimal irritation.
Is PHA gentler than AHA?
Yes, its larger molecule size means slower, more surface-level penetration, making it much better tolerated than glycolic or lactic acid.
Can sensitive skin use gluconolactone?
Yes, it's often the exfoliating acid recommended specifically for sensitive, rosacea-prone, or reactive skin.
Can I use gluconolactone every day?
Most people tolerate daily use well, though starting a few times a week is reasonable if new to exfoliating acids.
Is gluconolactone safe during pregnancy?
Yes, PHAs like gluconolactone are generally considered a safe exfoliation option during pregnancy.