An occlusive is a moisturizing ingredient that forms a physical barrier on top of your skin to prevent water from evaporating. Unlike ingredients that add moisture, occlusives lock in the hydration already there. Petrolatum (the main ingredient in petroleum jelly) is the most effective occlusive available, capable of reducing water loss from the skin by up to 98%.
How Occlusives Work
Your skin constantly loses water to the air through a process called transepidermal water loss, or TEWL. This is normal, but when your skin barrier is compromised from dryness, harsh weather, or irritation, that water loss accelerates, leaving skin feeling tight, flaky, and dehydrated.
Occlusives work by sitting on the skin’s surface and creating a seal. Think of it like plastic wrap over a bowl of food: the moisture inside can’t escape. This is fundamentally different from how other moisturizing ingredients function. Occlusives don’t pull water into the skin or fill in rough texture. They simply trap what’s already there.
Occlusives vs. Humectants vs. Emollients
Moisturizing ingredients fall into three categories, and most products blend all three. Understanding the difference helps you choose what your skin actually needs.
- Humectants attract water. They pull moisture from the air (and from deeper layers of your skin) up to the surface. Glycerin and hyaluronic acid are common examples.
- Emollients smooth and soften. They fill in the tiny gaps between skin cells that make your skin feel rough or flaky. Fatty acids and ceramides work this way.
- Occlusives seal everything in. They form that physical barrier on top to prevent moisture from escaping.
These categories aren’t always separate. Some ingredients do double duty. Shea butter, for instance, acts as both an emollient and an occlusive. But the core distinction matters: humectants bring water in, emollients smooth the surface, and occlusives keep it all from leaving.
Common Occlusive Ingredients
Petrolatum is the gold standard. It’s the most effective occlusive ingredient studied, and it forms a nearly impenetrable moisture barrier. You’ll find it in products like Vaseline, Aquaphor, and many heavy-duty moisturizers. The downside is its thick, greasy texture, which makes it better suited for nighttime use.
Dimethicone, a type of silicone, is the second most widely used occlusive in moisturizers today. It’s popular because it’s lightweight, hypoallergenic, and won’t clog pores or cause acne. If you’ve ever used a moisturizer or primer that felt silky and smooth, dimethicone was likely doing the work. It doesn’t seal moisture as completely as petrolatum, but it’s far more comfortable to wear during the day.
Other occlusive ingredients include mineral oil, beeswax, lanolin, and various vegetable oils. Plant-based oils like those derived from seeds and nuts can provide meaningful occlusion, though they tend to take longer to build that barrier. Research comparing vegetable oils to petrolatum found that most reached comparable levels of occlusion over a six-hour period, but petrolatum provided a much stronger immediate seal within the first 15 minutes.
How to Layer Occlusives Into Your Routine
Because occlusives don’t add moisture on their own, they work best as the final step in your skincare routine. The idea is to apply your water-based products and humectants first, follow with any emollient-rich creams, and then seal everything with an occlusive on top. If you skip the earlier hydrating layers, you’re essentially locking a barrier over skin that hasn’t been given much moisture to hold onto.
Applying your occlusive while skin is still slightly damp, right after washing or misting, helps trap that extra surface moisture before it evaporates. This is especially useful in winter, when cold outdoor air and indoor heating both pull water from your skin. During warmer months, switching to a lighter silicone-based occlusive keeps you from feeling greasy while still providing protection.
Slugging: The Overnight Occlusive Trend
Slugging is the practice of coating your face with a thick layer of petroleum jelly before bed. The name comes from the shiny, slug-like appearance it gives your skin. It’s essentially occlusion taken to the extreme, and it works. The petroleum jelly seals in hydration overnight and also keeps environmental irritants from reaching the skin’s surface.
There’s one important caution with slugging. That same barrier that traps moisture also traps whatever you applied underneath. If you’ve used products with active ingredients like AHAs, BHAs, or retinoids, the occlusive layer can increase their penetration and cause redness or irritation. On slugging nights, keep your routine simple: cleanser, a basic hydrating product, then the petroleum jelly.
Occlusives and Acne-Prone Skin
The biggest concern with occlusives is pore clogging. Heavy occlusives like lanolin, coconut oil, and certain hydrogenated oils are comedogenic, meaning they can block pores and trigger breakouts. If you have oily or acne-prone skin, these are worth avoiding.
That doesn’t mean occlusives are off-limits for you. Dimethicone is both noncomedogenic and nonacnegenic, making it a reliable option for acne-prone skin that still needs moisture protection. Petrolatum, despite its heavy texture, is also generally considered noncomedogenic, though the thick feel can be uncomfortable for people who already produce excess oil. The key is choosing the right occlusive rather than avoiding the category entirely.
Occlusives Beyond Skincare
The occlusive principle extends well beyond face creams. In wound care, occlusive dressings use the same concept to speed healing. By maintaining a moist environment over a wound, these dressings increase the rate of skin regrowth by 30% to 45% and help acute wounds heal an average of three to four days faster than traditional dry dressings. The moisture barrier prevents the wound from drying out, reduces pain, lowers infection risk by blocking outside bacteria, and supports the body’s natural tissue repair processes.
This same logic applies to everyday situations. Lip balms with beeswax or petrolatum are occlusives. Diaper creams with zinc oxide create an occlusive barrier. Even the simple act of wearing shoes creates a natural occlusive effect on the soles of your feet, which is why that skin retains moisture despite having more sweat glands than almost anywhere else on the body.