What Are Occlusives?
How occlusive ingredients work, which ones to use, and how they fit into a formula
Occlusives are ingredients that form a physical barrier on the skin surface, slowing the evaporation of water through the skin — a process called transepidermal water loss (TEWL). Unlike humectants, which attract water, occlusives work by physically blocking water from leaving. They are one of the three core functional categories in moisturizer formulation, alongside humectants and emollients.
How occlusives work
The outer layer of skin (stratum corneum) naturally limits water loss, but it is imperfect — water constantly evaporates through it. Dry skin, damaged skin barrier, or low-humidity environments increase TEWL. Occlusives sit on top of the skin and reduce the rate of that evaporation, keeping moisture in.
The three moisturizer mechanisms
Humectant — attracts water molecules to the skin surface (glycerin, hyaluronic acid)
Emollient — fills gaps between skin cells; smooths and softens the surface (oils, esters)
Occlusive — forms a physical film to slow water evaporation (petrolatum, beeswax, dimethicone)
The most effective moisturizers use all three. Humectants attract water; occlusives keep it there. Without occlusion, humectants can draw moisture to the surface where it evaporates — leaving skin no better (or worse) than before.
Common occlusives compared
| Occlusive | Occlusion strength | Product type | Notes |
|---|---|---|---|
| Petrolatum (petroleum jelly) | Very high | Balms, ointments, creams | Most effective; refined grades are safe; not vegan |
| Mineral oil (white mineral oil) | High | Creams, lotions, baby products | Highly refined; lightweight; non-comedogenic in refined form |
| Dimethicone | Moderate–High | Lotions, serums, primers | Silicone; silky feel; non-comedogenic; excellent skin tolerance |
| Beeswax | High | Lip balms, balms, sticks | Natural; not vegan; firms and thickens; good for anhydrous |
| Carnauba wax | High | Balms, sticks | Plant-derived; harder than beeswax; high melt point |
| Candelilla wax | Moderate–High | Vegan lip balms, balms | Harder than beeswax; vegan alternative |
| Shea butter | Moderate | Creams, butters, balms | Also emollient; natural; popular; moderate TEWL reduction |
| Cocoa butter | Moderate | Creams, lotions, balms | Good occlusion; characteristic scent unless deodorized |
| Lanolin | High | Lip balms, nipple creams, ointments | Very effective; not vegan; some sensitization in prone individuals |
| Cetyl/cetearyl alcohol | Low–Moderate | Creams, lotions | Fatty alcohols; more emollient than occlusive; contribute texture |
Occlusives in anhydrous formulas (balms and sticks)
In anhydrous products — lip balms, body balms, salves, lotion bars — occlusives are the primary functional ingredients. The formula is essentially a blend of occlusives and emollients with no water phase:
- Waxes (beeswax, carnauba, candelilla) — provide structure, firmness, and occlusivity
- Butters (shea, cocoa, mango) — emollient + moderate occlusion
- Oils (castor, jojoba, sweet almond) — emolliency and slip
- Petrolatum or mineral oil — when maximum TEWL reduction is the goal
Pro Tip
Occlusives in emulsions
In O/W lotions and creams, occlusives contribute to the formula's ability to retain moisture after application. They go in the oil phase:
- Beeswax, cetyl alcohol, and cetearyl alcohol thicken the oil phase and contribute to the cream's texture and occlusion.
- Dimethicone (0.5–5%) can be added to the oil phase; it contributes slip, occlusion, and a silky after-feel.
- Shea butter and cocoa butter added at 2–10% improve occlusion and richness.
- Mineral oil or petrolatum at 2–5% significantly boosts TEWL reduction without making the emulsion feel heavy if properly emulsified.
Occlusion is not the same as greasiness