Quick Comparison
| Gluconolactone (PHA) | Hyaluronic Acid | |
|---|---|---|
| Typical Concentration | Concentrations: 4-15%. Can often be used daily even by sensitive skin types. Apply morning or night. No sun sensitivity increase (unlike AHAs). pH range: 3.5-4.5. | Concentrations: 0.1-2%. Higher is not always better — concentrations above 2% can feel sticky and may actually pull moisture FROM skin in dry climates. Multi-molecular weight formulations are preferred. Apply to damp skin and seal with moisturizer. |
| Application | Topical (serum, toner, cream). Gentle enough for daily use on most skin types. | Topical (serum, cream, mask). Apply to damp skin and layer occlusive on top. Injectable HA fillers are a separate medical category. |
| Research Papers | 4 papers | 10 papers |
| Categories |
Mechanism of Action
Gluconolactone (PHA)
Gluconolactone hydrolyzes desmosomal proteins and glycosaminoglycan bonds between corneocytes in stratum corneum, promoting desquamation. Large molecular size (178 Da vs glycolic acid 76 Da) means slow, even penetration through lipid bilayer — no irritation-causing 'hot spots' of concentrated acid. Gentle, sustained exfoliation. Six hydroxyl groups per molecule make it a potent humectant, forming hydrogen bonds with water and drawing moisture into stratum corneum. Chelates iron and copper ions, reducing metal-catalyzed free radical formation. Has antioxidant properties. Unlike AHAs, does not increase UV sensitivity. Lactone ring hydrolyzes to gluconic acid at skin pH. Ideal for sensitive skin, rosacea, those intolerant of glycolic or salicylic acid.
Hyaluronic Acid
Hyaluronic acid is a glycosaminoglycan (GAG) composed of repeating D-glucuronic acid and N-acetyl-D-glucosamine disaccharides. Its hydroxyl and carboxyl groups create strong hydrogen bonding with water—each molecule binds up to 1000x its weight in water. High molecular weight HA (>1000 kDa) forms a viscoelastic film on the stratum corneum, reducing transepidermal water loss (TEWL). Medium weight (100-1000 kDa) penetrates the upper epidermis. Low molecular weight HA (<100 kDa) reaches the dermis and binds CD44 and RHAMM receptors on fibroblasts, triggering ERK and PI3K signaling that stimulates fibroblast proliferation, hyaluronan synthase (HAS2) expression, and collagen I/III synthesis. Sodium hyaluronate—the salt form—has improved stability and penetration. Multi-weight formulations provide surface hydration and deeper dermal stimulation.
Risks & Safety
Gluconolactone (PHA)
Common
Essentially none — one of the most tolerated exfoliants. Slight stickiness.
Serious
None.
Rare
Mild irritation in extremely reactive skin.
Hyaluronic Acid
Common
Stickiness at high concentrations. In very dry/arid climates, HA can draw moisture from deeper skin layers to the surface where it evaporates.
Serious
None.
Rare
Mild irritation from very low molecular weight HA penetrating too deeply.
Full Profiles
Gluconolactone (PHA) →
A polyhydroxy acid (PHA) — the gentlest class of chemical exfoliants. Gluconolactone has a very large molecular size, so it works extremely slowly on the skin surface without penetrating deeply. This makes it ideal for extremely sensitive skin, rosacea-prone skin, and those who cannot tolerate AHAs or BHAs. It also acts as a humectant, drawing moisture into the skin as it gently exfoliates.
Hyaluronic Acid →
The most popular hydrating ingredient in skincare. Hyaluronic acid (HA) is a glycosaminoglycan naturally produced by the body that can hold up to 1,000x its weight in water. In skincare, different molecular weights serve different functions: high molecular weight HA sits on the skin surface forming a moisture barrier, while low molecular weight HA penetrates deeper layers for plumping hydration.