Meet the Ingredients: A Closer Look at the Key Hydrating Ingredients

•  Hyaluronic acid is one of the skin's most powerful natural water-attracting molecules and is suitable for all skin types and can be sealed in with occlusive ingredients to work effectively.
• Glycerin is an extensively researched moisturizing ingredient in dermatology and is recommended by many dermatologists as a reliable, low-irritation option for all skin types.¹
• Ceramides make up approximately 50% of the skin's outer surface layer and are clinically linked to barrier function. All CeraVe products contain three skin-identical ceramides.²
• Urea, petrolatum, and dimethicone each perform specialized roles across different skin types and conditions, from intensive repair to breathable everyday protection.

Understanding the three categories of moisturizing ingredients (humectants, emollients, and occlusives) is important. But the next question most people ask is a practical one: which specific ingredients should I be looking for on the label, and what are they actually doing to my skin?

CeraVe's hydrating cleansers and moisturizers use varying combinations and concentrations of these ingredients to address different skin types and concerns. This article takes a closer look at some key ingredients and what they do.

Hyaluronic Acid, The Water Magnet

What it is: Hyaluronic acid (also known as hyaluronan or sodium hyaluronate) is a naturally occurring humectant found in the skin. Its primary biological job is to hold onto water.⁴ It is one of the most powerful water-attracting substances known, capable of holding up to 1000x its own weight in water.⁵

What it does in your skin: Hyaluronic acid draws water into the skin's surface layer, making skin look and feel more plump, hydrated, and comfortable. As we age, the skin's natural supply of hyaluronic acid decreases, which is one of the reasons mature skin tends to lose that bouncy, well-hydrated quality over time.⁶

Derm's Tip: Hyaluronic acid performs best when applied to slightly damp skin then followed immediately by a moisturizer. Used alone on dry skin, especially in low-humidity environments, it can pull moisture from deeper skin layers to the surface where it then evaporates, leaving skin feeling tighter than before.

Glycerin, A Fundamental Moisturizer in Dermatology

What it is: Glycerin (also known as glycerol) is an extensively studied moisturizing ingredient in dermatology. It is a clear, odourless liquid that occurs naturally in the skin as part of the body's own hydration system.⁸ Glycerin is recommended by dermatologists as an effective ingredient for relieving dry skin.¹

What it does in your skin: Like hyaluronic acid, glycerin is a humectant. It draws water into the skin and has additionally been shown to support the skin's natural recovery of barrier function.⁹

Ceramides, The Mortar That Holds Your Barrier Together

What they are: Ceramides are natural fats (lipids) that the skin produces on its own. They make up approximately 50% of the skin's outer surface layer (a.k.a the stratum corneum), making them the single most structurally important component of the skin barrier.^1,10

What they do in your skin: Ceramides are the mortar in the skin's brick wall. When ceramide levels decline due to ageing, harsh cleansing, environmental exposure, or skin conditions like eczema, the wall develops gaps. When that happens, the skin loses moisture more rapidly, becomes sensitive to products it previously tolerated, and reacts more easily to environmental stressors like cold air, wind, and pollution. The clinical link between low ceramide levels and skin conditions including atopic dermatitis is well documented.¹¹

Urea, The Intensive Repair Molecule

What it is: Urea is a naturally occurring molecule that forms part of the skin's own Natural Moisturizing Factors (NMF), the network of compounds that maintain water content within the skin’s protective barrier. In skincare, it is used at varying concentrations for different purposes.¹²

What it does in your skin: At lower concentrations (typically up to 10%), urea functions as a humectant: it draws water into the skin, softens roughness, and helps restore moisture balance. It is particularly effective for very dry, rough, or flaky skin that requires more intensive hydration than standard everyday moisturizers provide.¹²

Good for: Very dry, rough, or flaky skin. Suitable for dry skin on the body, hands, feet, and elbows.

Petrolatum, The Gold Standard Occlusive

What it is: Petrolatum (also known as petroleum jelly) is widely regarded as the gold standard of occlusive ingredients in dermatology. It is often integrated into cosmetic use and has a comprehensive safety and efficacy track record.¹³

What it does in your skin: Petrolatum creates a protective physical layer on top of the skin that dramatically slows the evaporation of moisture (TEWL). It does not add water to your skin. Its role is to keep the moisture already present from escaping.¹⁴ This is why it works best as the final step in your routine, applied after humectants like glycerin and hyaluronic acid that have already drawn water into the skin.

Good for: Very dry skin, cracked or chapped skin, significantly weakened skin barrier, targeted overnight repair on dry patches.

Dimethicone, The Breathable Everyday Shield

What it is: Dimethicone is a type of silicone used in skincare as a lightweight ingredient that functions as both an occlusive and an emollient. It has a well-established safety profile and is classified as non-comedogenic and hypoallergenic.¹⁵

What it does in your skin: Like petrolatum, dimethicone forms a protective layer on the skin that slows moisture loss. Its key advantage for daily use is that it is permeable to water vapour¹⁶, meaning the skin can still breathe, sweat, and function normally beneath it. This makes it particularly comfortable for all-day wear, especially under makeup or sunscreen. Its lightweight, non-greasy texture also makes it better suited to oily and combination skin types than heavier occlusives.

If petrolatum is a sealed lid, dimethicone is a breathable mesh cover. It still slows moisture loss significantly, but lets your skin breathe underneath it.

Good for: Oily or combination skin. Ideal as part of everyday facial moisturizers and products worn under makeup.

Squalane Oil, The Skin-Compatible Oil

What it is: Squalane is a lightweight, stable oil derived from squalene, a lipid the skin naturally produces as part of its own sebum.³ Because raw squalene oxidises rapidly on exposure to air, it is converted through a process called hydrogenation into squalane: a stable form that retains all the skin-compatibility benefits without the oxidative instability.¹⁷

What it does in your skin: Because squalane so closely mirrors the skin's own natural lipids, the skin barrier recognises and absorbs it readily, without the greasy or heavy feel associated with richer oils. As an emollient, it fills microscopic gaps between skin cells, restoring smoothness and flexibility to the skin's surface. It also forms a lightweight film that reduces moisture loss, providing gentle occlusive support appropriate for everyday use.³

Squalane has a very low comedogenic rating of 0-1¹⁸, meaning it will not clog pores. This makes it one of the very few oils considered appropriate for all skin types, including sensitive or oily and acne-prone skin.¹⁷

Think of squalane as giving your skin back something it already makes but produces less of as you age. It is a familiar, lightweight lipid that slots naturally into the barrier without disrupting it.

Good for: Particularly beneficial for dry, mature, and sensitive skin that needs lightweight yet effective hydrating support.

Understanding individual ingredients allows you to read a product label with purpose. Here are some practical tips on matching ingredients to your skin's needs.

For Dry or Very Dry Skin

Prioritize products that combine all three categories in richer formulations. Look for glycerin and hyaluronic acid as humectants, ceramides and squalane as emollients, and petrolatum or dimethicone as occlusives. At night, consider adding a targeted healing ointment over particularly dry or cracked areas to accelerate barrier repair while you sleep.

For Oily or Acne-Prone Skin

Lightweight and breathable are the keywords. Gel-textured moisturizers with glycerin or hyaluronic acid as the primary humectant, squalane as a non-comedogenic emollient, and dimethicone as a breathable occlusive provide complete hydration without congesting pores. Skipping moisturizer when skin feels oily can actually worsen oil production over time, as a dehydrated skin barrier triggers increased sebum production to compensate.

For Sensitive or Barrier-Compromised Skin

Focus on ingredients with strong biocompatibility and low irritation risk. Glycerin, ceramides, and squalane are all well-tolerated. It is best to avoid high concentrations of fragrance, alcohol, or active exfoliants in skincare products.

For Mature Skin

As skin ages, both natural ceramide levels and hyaluronic acid levels decline. Formulas that replenish both, alongside supportive occlusives, is key to maintaining the skin's resilience and hydrated appearance. You might want to look at more intensive formula with hydro-urea.

The above guidance is general in nature. If you have a diagnosed skin condition such as atopic dermatitis, rosacea, or psoriasis, consult a dermatologist before making significant changes to your moisturizing routine. Individual skin responses can vary, and a specialist can recommend specific formulations suited to your skin's needs.