We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Pha4.0
Polyhydroxy Acids (PHA) Research
Mostly mechanism / observationalHigh safety
6 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most Polyhydroxy Acids (PHA) studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality randomised trials published 2004–2010 with a typical study size of 77 participants.
Based on 6 studies · 2 RCTs · 77 total participants
Confidence
Low
By outcome
Skin healthGentle exfoliation plus humectant/antioxidant support for smoother, healthier-looking skin, suited to sensitive skin (cosmetic, not a health outcome) · 4-12 weeks · Modest anti-aging/texture improvement comparable to AHAs, with better tolerability (cosmetic) · 8-12 weeks
Mostly mechanism / observational5 studies
Skin tone & pigmentation
Too few graded studies1 study
Older research base
Newest study from 2010
20042010
1RCT2004
Both regimens showed significant antiaging benefits to skin as measured by silicone replicas, clinical grading, and pinch recoil for skin resiliency.
12-week controlled facial trial comparing a gluconolactone (PHA) regimen with a glycolic acid (AHA) regimen for photoaging
Both produced significant anti-aging benefit; AHA modestly beat PHA on only 2 endpoints (sallowness, pinch recoil)
The PHA regimen was significantly better tolerated (less stinging, burning, sensitivity); industry (NeoStrata) authorship
2RCTn=77 · small study2010
LA-containing samples has produced better skin performance when compared with corresponding GA-containing ones, particularly the lack of both skin irritation and skin barrier impairment.
Tasic-Kostov M, Savic S, Lukic M, Tamburic S, Pavlovic M, Vuleta G. · J Cosmet Dermatol (2010)
Gluconolactone provided up to 50% protection against UV radiation, as measured in our in vitro system, and did not significantly increase sunburn cells in human skin.
Bernstein EF, Brown DB, Schwartz MD, Kaidbey K, Ksenzenko SM. · Dermatol Surg (2004)
In-vitro photoaging model testing the antioxidant/chelating mechanism of gluconolactone
Gluconolactone gave up to ~50% protection against UV-induced elastin-promoter activation in vitro
In human skin it did not significantly increase UV-induced sunburn cells — no photosensitization signal
We lowered the pH of mouse SC using two polyhydroxyl acids (PHA), lactobionic acid (LBA), or gluconolactone (GL).
Hachem JP, Roelandt T, Schürer N, Pu X, Fluhr J, Giddelo C, Man MQ, Crumrine D, Roseeuw D, Feingold KR, Mauro T, Elias PM. · J Invest Dermatol (2010)
Independent preclinical (mouse) study applying lactobionic acid and gluconolactone to the stratum corneum
Both PHAs acidified the stratum corneum and improved permeability-barrier homeostasis via increased ceramide-generating enzyme activity
PHA acidification produced 'supernormal' stratum-corneum integrity by reducing serine-protease degradation of corneodesmosomes — a barrier-strengthening mechanism
PHAs have been found to be compatible with clinically sensitive skin, including rosacea and atopic dermatitis, and can be used after cosmetic procedures.