Understanding Humectants in Skincare: How They Help Keep Skin Hydrated

Introduction

If you have ever wondered why ingredients such as glycerine and hyaluronic acid appear in so many skincare products, the answer is often hydration.

These ingredients belong to a group called humectants. Humectants are widely used in lotions, creams, serums, toners, cleansers and other water-based cosmetic formulations.

Understanding how humectants work can help you formulate products that leave the skin feeling softer, smoother and more hydrated.

Let’s take a closer look at these useful cosmetic ingredients.

What Is a Humectant?

A humectant is a cosmetic ingredient that helps attract and hold water.

Humectants are generally water-loving ingredients. They can help increase the water content of the skin’s outer layers, giving the skin a more hydrated and comfortable feel.

Common cosmetic humectants include:

• Glycerine
• Hyaluronic acid
• Propanediol
• Butylene glycol
• Sorbitol
• Sodium PCA
• Panthenol
• Urea

Different humectants have different properties, so they are not necessarily interchangeable.

Glycerine – The Classic Humectant

Glycerine, also called glycerol, is one of the most widely used humectants in cosmetic formulation.

It is useful in products such as:

• Face creams
• Body lotions
• Hand creams
• Facial cleansers
• Toners
• Serums
• Soaps and syndet products

Glycerine is effective, affordable and easy to incorporate into many water-based formulations.

However, more is not always better. High levels can make a product feel sticky or tacky.

Hyaluronic Acid

Hyaluronic acid is another popular humectant.

Despite the word “acid” in its name, hyaluronic acid is not an exfoliating acid like glycolic acid or salicylic acid.

It is a naturally occurring substance that has a strong ability to bind water.

In skincare products, hyaluronic acid is commonly used in:

• Hydrating serums
• Face creams
• Gel creams
• Moisturisers
• Eye-area products

Different molecular weights of hyaluronic acid can have different properties and sensory characteristics.

Panthenol

Panthenol, also known as provitamin B5, is another popular ingredient in moisturising and conditioning formulations.

It can be found in:

• Moisturisers
• Serums
• Hair conditioners
• Shampoos
• Body lotions
• After-sun products

Panthenol is valued not only for its moisturising properties but also for the pleasant skin and hair feel it can provide.

Can You Use More Than One Humectant?

Yes.

Formulators often combine different humectants to create a particular skin feel and hydration profile.

For example, a formulation might contain glycerine together with hyaluronic acid.

However, every ingredient should have a reason for being included. Adding more ingredients does not automatically create a better product.

The final formulation should be evaluated for:

• Skin feel
• Stickiness
• Stability
• Compatibility
• Preservation
• pH
• Overall performance

How Much Humectant Should You Use?

There is no single usage rate that applies to every humectant or every product.

The correct amount depends on:

• The specific humectant
• The supplier’s recommended usage rate
• The type of product
• The other ingredients in the formula
• The desired skin feel

Always check the technical documentation supplied by your ingredient manufacturer.

For beginners, it is particularly important not to simply increase the percentage because a product does not feel moisturising enough.

The entire formulation may need to be considered.

Humectants Need Water

Humectants are particularly useful in formulations containing water.

Examples include:

• Lotions
• Creams
• Toners
• Facial mists
• Serums
• Body washes
• Shampoos

An important point for beginner formulators is that adding a humectant does not eliminate the need for a suitable preservative in a water-containing product.

A water-based product still needs an appropriate preservation system.

Humectants vs Emollients vs Occlusives

These three terms are often confused.

Humectants

Help attract and retain water.

Examples:

Glycerine, hyaluronic acid and panthenol

Emollients

Help soften and smooth the skin.

Examples include:

Plant oils, esters and cosmetic butters

Occlusives

Help reduce water loss from the skin by forming a protective layer.

Examples include:

Petrolatum, certain waxes and some silicones

A well-designed moisturiser may contain ingredients from all three categories.

Why Does My Lotion Feel Sticky?

One common complaint when using humectants is a sticky or tacky after-feel.

This can happen when the humectant level is too high for the particular formulation or when several highly humectant ingredients are combined.

Other ingredients can also influence the final sensory experience.

If your lotion feels sticky, don’t immediately assume that the humectant is “bad”.

Instead, look at the complete formulation and consider:

• Humectant concentration
• Oil phase
• Emulsifier
• Thickener
• Water level
• Other active ingredients
• Application amount

Small formulation changes can make a significant difference to skin feel.

Does Glycerine Dry Out the Skin?

You may have heard the claim that glycerine can “pull moisture out of the skin.”

This is an oversimplification.

Glycerine is a well-established humectant used in moisturising formulations. The performance of a cosmetic product depends on the complete formulation and the conditions in which it is used, rather than one ingredient considered in isolation.

A properly formulated moisturiser can combine humectants with emollients and occlusive ingredients to provide a pleasant and effective moisturising product.

Formulation Tip: Balance Is Key

One of the most important lessons in cosmetic formulation is that ingredients work as part of a system.

For example:

Humectant + water + emollient + occlusive

can create a very different product from one containing a high level of humectant alone.

When developing a new formulation, change one thing at a time and keep detailed notes.

Record:

• Formula percentage
• Batch size
• Ingredient supplier
• Manufacturing date
• Mixing procedure
• pH
• Texture
• Appearance
• Skin feel
• Stability observations

This makes it much easier to understand what is happening in your formulation.

Final Thoughts

Humectants are some of the most useful ingredients in skincare formulation.

From classic glycerine to hyaluronic acid and panthenol, they can help create products designed to leave the skin feeling hydrated and comfortable.

The key is not simply adding as much humectant as possible. Good formulation is about balance.

Understand what each ingredient does, use appropriate percentages, follow your supplier’s technical recommendations and always evaluate the finished product as a complete formulation.

At Fun with Soap, we believe that understanding your ingredients is the first step towards becoming a confident cosmetic formulator.

Keep learning, keep experimenting and have fun with soap!