Quick Comparison
| Ceramides | Gluconolactone (PHA) | |
|---|---|---|
| Typical Concentration | Look for products containing ceramide NP (ceramide 3), ceramide AP (ceramide 6-II), and ceramide EOP (ceramide 1) — these are the most abundant in human skin. Often combined with cholesterol and fatty acids in the optimal 3:1:1 ratio. Apply as moisturizer morning and night. | 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. |
| Application | Topical (cream, lotion, serum). Best in emollient/occlusve formulations rather than water-based serums. | Topical (serum, toner, cream). Gentle enough for daily use on most skin types. |
| Research Papers | 10 papers | 4 papers |
| Categories |
Mechanism of Action
Ceramides
Ceramides are sphingolipids comprising a sphingoid base (sphingosine or phytosphingosine) amide-linked to a fatty acid—comprising ~50% of stratum corneum lipids. They integrate into the intercellular lipid matrix between corneocytes, forming the lamellar bilayer structure with cholesterol and free fatty acids that limits transepidermal water loss (TEWL). Optimal molar ratio is ~3:1:1 (ceramides:cholesterol:fatty acids). Topical ceramides (NP/3, AP/6-II, EOP/1) fill gaps from barrier damage by surfactants, retinoids, or inflammation. Cholesterol enables lamellar phase formation; fatty acids provide acidic pH for ceramide packing. Products restoring the complete ratio upregulate barrier repair genes (involucrin, filaggrin, transglutaminase) more effectively. Synthesis occurs via serine palmitoyltransferase and ceramide synthase in keratinocytes.
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.
Risks & Safety
Ceramides
Common
Essentially none — ceramides are bioidentical to skin components.
Serious
None. Safe for all skin types including sensitive, eczema-prone, and rosacea.
Rare
Virtually no risk.
Gluconolactone (PHA)
Common
Essentially none — one of the most tolerated exfoliants. Slight stickiness.
Serious
None.
Rare
Mild irritation in extremely reactive skin.
Full Profiles
Ceramides →
Lipids that make up approximately 50% of the skin barrier by weight. Ceramides form the 'mortar' between skin cells (the 'bricks'), creating a waterproof barrier that prevents water loss and keeps irritants out. When the skin barrier is damaged — from over-exfoliation, harsh cleansers, retinoid use, or conditions like eczema — ceramide levels are depleted, and replenishing them is essential for recovery.
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.