Quick Comparison
| Ceramides | Petrolatum (Vaseline) | |
|---|---|---|
| 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. | Apply thin layer over damp skin or over other skincare products. Can be used as 'slugging' (applying all over face at night). Safe for daily use. Especially effective over retinoids to buffer irritation. |
| Application | Topical (cream, lotion, serum). Best in emollient/occlusve formulations rather than water-based serums. | Topical (ointment, lip balm). Apply as final step to seal in moisture. Thin layer is sufficient. |
| Research Papers | 10 papers | 10 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.
Petrolatum (Vaseline)
Petrolatum is a mixture of long-chain saturated hydrocarbons (C16-C32) that forms a semi-occlusive film—reducing transepidermal water loss (TEWL) by up to 99%. It penetrates intercellular spaces of the stratum corneum, filling gaps in the lipid lamellae and creating a hydrophobic barrier. This occlusive environment raises stratum corneum water content, activating endogenous repair: upregulation of antimicrobial peptides (defensins, cathelicidin LL-37), lamellar body secretion, and barrier lipid synthesis. The stratum corneum obtains oxygen from dermal circulation, not the atmosphere. Studies demonstrate accelerated wound healing and barrier recovery, contradicting infection myths.
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.
Petrolatum (Vaseline)
Common
Greasy feel. May trap bacteria if applied over unwashed skin (cleanse first).
Serious
None when using cosmetic-grade/USP petrolatum.
Rare
Allergic reaction is extremely rare. Concerns about contamination (PAHs) apply only to industrial-grade, not cosmetic-grade petrolatum.
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.
Petrolatum (Vaseline) →
The most effective occlusive ingredient available — petrolatum reduces transepidermal water loss (TEWL) by 99%. Despite misconceptions, it does not clog pores and does not prevent skin from 'breathing.' Dermatologists recommend it universally for barrier repair, wound healing, and locking in moisture. It is the standard against which all other moisturizing ingredients are measured.