What Are the Main Ingredients in a Skin Cream and How Do They Function in a Formula?

When developing a skin cream, selecting the right ingredients is more than just choosing what’s trending. Each component plays a specific role in the formula’s performance, from how it delivers hydration to how it feels on the skin and holds up over time.

For formulators, understanding the main ingredients in a skin cream means knowing how to balance function, stability, and sensory appeal. It’s about building a system where humectants, emollients, occlusives, and actives work together to deliver both immediate results and long-term benefits.

Humectants are essential to any well-balanced skin cream. They help maintain skin hydration by drawing water from the environment or deeper layers of the skin to the stratum corneum. Their ability to improve skin elasticity, plumpness, and overall comfort makes them a foundational component in moisturization strategies.

Some of the most widely used humectants include:

• Glycerin – Highly effective, cost-efficient, and compatible across pH ranges. Glycerin also helps improve skin barrier function.
• Hyaluronic acid (and its salts like sodium hyaluronate) – Known for its ability to hold up to 1,000 times its weight in water, it provides an immediate plumping effect and supports longer-term hydration.
• Panthenol – A provitamin of B5, panthenol is both a humectant and a soothing agent, often included for its calming properties in sensitive skin formulations.
• Sodium PCA – Naturally found in the skin’s natural moisturizing factors (NMF), it’s highly effective at binding moisture and enhancing skin softness.

Humectants function by attracting water molecules through hydrogen bonding. They can draw moisture from the atmosphere under high humidity conditions, or from deeper dermal layers when environmental humidity is low. This hydration helps temporarily increase skin volume, smooth out fine lines, and improve overall suppleness.

In emulsions, humectants often sit in the aqueous phase and are absorbed rapidly into the skin, making them ideal for delivering an initial hydration boost.

• Usage levels vary depending on the humectant. Glycerin is typically used at 2 to 10 percent, while sodium hyaluronate is often used at 0.1 to 1 percent depending on molecular weight.
• Compatibility is generally good with most emulsifiers and preservatives, but some humectants can interact with certain thickeners or actives.
• Stability is usually not a concern, although humectants with high water-binding capacity may affect viscosity over time or cause tackiness at high levels.
• Environmental conditions should be considered. In very dry climates, humectants without occlusive support may lead to transepidermal water loss (TEWL), pulling moisture from deeper layers rather than the environment.

Emollients play a critical role in enhancing the sensorial profile of a skin cream while also supporting the skin’s barrier function. They work by filling in spaces between corneocytes in the stratum corneum, helping to smooth the skin surface and improve softness. Emollients also contribute to the overall spreadability and richness of the formula, making them essential in both feel and function.

Formulators have access to a wide range of emollients, each offering different sensory, functional, and stability benefits. Common examples include:

• Shea butter – A rich, semi-solid natural butter known for its nourishing, occlusive, and anti-inflammatory properties. Ideal for dry and compromised skin.
• Caprylic/capric triglyceride – A lightweight ester derived from coconut oil and glycerin. Offers excellent spreadability and a silky afterfeel without greasiness.
• Esters (e.g., isopropyl myristate, cetearyl ethylhexanoate) – Provide various textures ranging from dry to oily. Esters are often used to fine-tune the skin feel.
• Silicones (e.g., dimethicone, cyclopentasiloxane) – Known for their smooth glide, barrier-enhancing properties, and ability to reduce tackiness from other ingredients.

Selecting the right emollient involves balancing functional performance with consumer preferences. Key considerations include:

• Skin type – Richer emollients like butters and heavier esters are better suited for dry or mature skin. Lightweight esters and silicones are often preferred for oily or combination skin.
• Sensory goals – Emollients can shift the final skin feel from dewy to matte, depending on their volatility, absorption rate, and finish.
• Formula format – Creams, lotions, and balms require different emollient blends to achieve the desired viscosity and application profile.
• Compatibility – Some natural emollients can affect emulsion stability or alter color and scent. Testing is essential for optimal performance and shelf life.

Occlusives are vital in skin cream formulations where moisture retention is a key goal. These ingredients create a physical barrier on the skin's surface, helping to prevent transepidermal water loss (TEWL). While humectants draw moisture into the skin and emollients help smooth the surface, occlusives ensure that hydration stays locked in. They are especially important in products designed for dry, sensitive, or compromised skin.

Occlusives vary in origin, feel, and functionality. Common examples include:

• Dimethicone – A silicone-based occlusive that forms a breathable barrier while providing a silky, non-greasy feel. Often used to reduce tackiness from other ingredients.
• Petrolatum – One of the most effective occlusives available. It provides near-complete occlusion but has a heavier, greasier finish. Common in ointments and therapeutic creams.
• Lanolin – A natural, waxy material derived from wool. Provides occlusion and emolliency, but may cause sensitivity in some users.
• Waxes (e.g., beeswax, candelilla wax) – Often used in combination with oils or butters to create semi-solid textures with added occlusive benefits.

Occlusives work by creating a hydrophobic layer over the skin. This layer acts as a shield, reducing the evaporation of water from the stratum corneum. The effectiveness of this barrier depends on the molecular structure and film-forming ability of the occlusive agent. While heavier occlusives like petrolatum provide near-total occlusion, lighter ones like dimethicone allow for some breathability, which can improve sensory appeal.

Occlusives are best used in formulations where barrier protection and long-lasting hydration are needed. They are especially relevant in:

• Cold weather products – Environmental exposure increases TEWL, making occlusives a key addition to winter skincare.
• Barrier repair treatments – Occlusives help restore the skin’s protective layer and support healing in dry, cracked, or irritated skin.
• Overnight creams and balms – These formulas benefit from slow absorption and prolonged hydration, which occlusives help maintain throughout the night.

When formulating with occlusives, balance is key. Too much can lead to a greasy feel or interfere with absorption, while too little may not provide the desired hydration benefits.

While base ingredients like humectants, emollients, and occlusives form the structure of a skin cream, it’s the active ingredients that deliver targeted results. These compounds address specific skin concerns such as hyperpigmentation, fine lines, inflammation, or dullness. Selecting and formulating with the right actives requires a deep understanding of their mechanisms and stability profiles.

Several high-performance actives are widely used in creams across product categories. Some of the most popular include:

• Niacinamide – A multifunctional ingredient known for brightening, reducing inflammation, and improving skin barrier function. It is typically used at 2 to 5 percent and is highly stable across pH ranges.
• Retinol – A vitamin A derivative that promotes cell turnover and smooths fine lines. Effective but unstable, requiring specific formulation techniques.
• Peptides – Short chains of amino acids that signal the skin to produce more collagen, improve firmness, or calm sensitivity. Peptides vary in structure and performance and are often used in anti-aging formulations.
• Vitamin C derivatives – Including ascorbyl glucoside, magnesium ascorbyl phosphate, and tetrahexyldecyl ascorbate. These provide antioxidant protection and skin-brightening effects with improved stability over pure ascorbic acid.

Active ingredients work at a cellular level, interacting with receptors or enzymes in the skin to trigger specific responses. For example:

• Brightening – Niacinamide inhibits melanosome transfer, while vitamin C reduces melanin synthesis.
• Firming – Peptides may stimulate collagen production or prevent its degradation.
• Calming – Some actives reduce inflammatory markers or reinforce the skin barrier.
• Smoothing – Retinol increases cellular turnover, reducing the appearance of fine lines and uneven texture.

Because these ingredients are biologically active, even small concentrations can have a noticeable effect on the skin, which is why they must be selected and dosed with care.

Stability and efficacy are top priorities when working with actives. Consider the following formulation approaches:

• Encapsulation – Helps protect sensitive ingredients (like retinol or vitamin C) from oxidation and enables controlled release.
• Read more: 7 Key Benefits of Encapsulation in Skincare
• pH compatibility – Each active has an optimal pH range. For example, ascorbic acid requires a low pH, while peptides and niacinamide prefer neutral to slightly acidic conditions.
• Delivery systems – Liposomes, microspheres, and nanoemulsions can improve penetration and reduce irritation.
• Preservation and packaging – Actives prone to degradation should be protected with antioxidants and stored in airless or UV-blocking containers when possible.

A successful formula depends not only on the actives themselves, but on how they’re integrated into the full system. Interactions with other ingredients, processing conditions, and packaging all play a role in performance and shelf life.

Preservatives are essential for protecting skin creams from microbial contamination, especially those containing water. Without an effective preservation system, a formulation is at risk for bacterial, yeast, and mold growth, which can compromise product safety, stability, and shelf life. Choosing the right preservative requires balancing efficacy, regulatory compliance, and compatibility with the overall formula.

Most emulsions require broad-spectrum protection, and these are some of the most commonly used preservatives in modern skin creams:

• Phenoxyethanol – A globally approved preservative effective against bacteria and yeast. Often used in combination with other preservatives to broaden efficacy.
• Ethylhexylglycerin – A multifunctional preservative booster with mild antimicrobial activity. Often paired with phenoxyethanol to improve performance and reduce irritation.
• Sodium benzoate – More commonly used in natural formulations. Effective primarily against fungi and requires a low pH to perform optimally.

These ingredients are typically used at low concentrations but must be validated through microbial challenge testing to ensure effectiveness in the final product.

Preservative efficacy depends on the unique characteristics of the formulation. Key factors to consider include:

• Water activity (aw) – The more free water in a product, the more susceptible it is to microbial growth. Emulsions and gels generally require stronger preservation than anhydrous or solid formulations.
• pH – Some preservatives only function within specific pH ranges. For example, sodium benzoate is effective below pH 5.5, while phenoxyethanol works across a broader pH range.
• Ingredient interactions – Certain ingredients, such as clays, ionic emulsifiers, or plant extracts, can reduce preservative effectiveness by binding to them or introducing microbial load. Formulators must evaluate interactions during compatibility testing.

A well-designed preservative system often involves synergistic combinations that provide coverage against a wide range of microorganisms while minimizing potential for irritation.

Texture and stability enhancers are the unsung heroes that shape the feel, appearance, and long-term integrity of a skin cream. While these ingredients may not have visible benefits for the skin, they are essential for ensuring a pleasant user experience and maintaining product consistency over time. From viscosity control to emulsion stabilization, these materials help bring the formula together and keep it performing as intended.

These are some of the most common ingredients used to enhance texture and stability:

• Carbomer – A synthetic polymer used to create clear gels and thicken emulsions. It provides excellent suspension properties and a smooth, elegant texture, especially when neutralized.
• Xanthan gum – A natural polysaccharide derived from fermentation. Commonly used in natural formulations to add viscosity and prevent phase separation.
• Cetearyl alcohol – A fatty alcohol that acts as both an emollient and a co-emulsifier. It contributes to the creamy texture of emulsions and enhances product stability.

Each of these ingredients has a different sensory impact and requires specific processing techniques for optimal performance.

Read more: How to Choose the Right Rheology Modifier for Your Cosmetic Formulation

Texture enhancers influence how a cream feels during application and how it transitions during rub-in. For example:

• Thickeners like carbomer and xanthan gum increase viscosity, which can make a formula feel richer or more cushiony on the skin.
• Fatty alcohols like cetearyl alcohol contribute to slip and structure, supporting both the cream’s body and glide.

These elements are often used to tailor the sensorial profile based on brand positioning, climate, or end-user preference.

In emulsions, texture and stability enhancers play a critical role in maintaining uniformity. They help:

• Stabilize the emulsion by increasing viscosity and reducing the mobility of oil and water phases, which minimizes the risk of separation or creaming.
• Suspend particles such as pigments or exfoliants evenly throughout the formula.
• Improve shelf life by enhancing formula integrity over time, especially under varying temperature conditions.

Proper selection and concentration of these ingredients are essential to ensure compatibility with actives, preserve product performance, and support consumer expectations for consistency and quality.

Fragrance is one of the most polarizing elements in a skin cream. For many consumers, it creates an emotional connection to the product and enhances the overall experience. For others, especially those with sensitive skin or fragrance allergies, it can be a source of irritation or concern. As a formulator, it’s important to weigh both sensory appeal and skin compatibility when deciding whether or not to include fragrance or essential oils.

Fragrance is often used to:

• Enhance the user experience by adding a signature scent or masking the natural odor of raw materials
• Support brand identity by maintaining a consistent olfactory profile across product lines
• Drive product perception since consumers often associate scent with product quality or efficacy

However, fragrances—both synthetic and natural—are among the most common cosmetic allergens. Even at low levels, they may cause skin reactions, especially in products used on the face, damaged skin, or by individuals with conditions like eczema or rosacea. Essential oils, though perceived as natural and gentle, can also contain allergenic compounds such as limonene, linalool, or eugenol.

Formulators must balance sensory goals with safety, especially when targeting sensitive skin or global regulatory compliance.

Read more: Essential Oils for Skincare

These two terms are often misunderstood by consumers and misused in marketing, so clarity is essential:

• Fragrance-free means the product contains no added fragrance ingredients, whether synthetic or natural. The product may still have a scent due to the natural odor of the raw materials.
• Unscented means the product may contain masking agents to neutralize or hide odors but is not intended to have a noticeable scent. Unscented products may still contain small amounts of fragrance components.

Understanding the difference is important when labeling your product or responding to consumer questions about formulation transparency.

If a product is designed for sensitive skin or compromised barriers, it is often best to avoid fragrance altogether. Consider the following formulation strategies:

• Use raw materials with minimal odor to reduce the need for masking agents
• Highlight fragrance-free claims for sensitive skin lines
• Patch test essential oils in early development stages if they are required for a natural positioning
• Check regulatory and allergen labeling requirements (such as the EU's list of 26 fragrance allergens)

When in doubt, a minimalist approach to scent can help ensure wider tolerance, especially in formulations designed for facial use, post-treatment skin, or pediatric applications.

As a formulator, building an effective skin cream means thinking beyond just hydration or hero ingredients. It’s about constructing a formula that works holistically, delivering the right sensory experience, meeting performance goals, and staying stable and safe over time.