Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!

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Betaine

Humectant, Skin Conditioning

Betaine is a humectant. Like hyaluronic acid, it helps attract and retain moisture in the skin. It’s known for being gentle and for helping the skin maintain balanced hydration.

Betaine is mainly used to improve hydration and support calmer skin. It helps skin cells regulate water balance because it functions as an osmolyte.

Some studies suggest betaine may support making skin tone more even.

Fun fact: Betaine naturally exists in the skin and the body. In cosmetic products, it can be either plant-derived (most commonly from sugar beets) or synthetically produced for consistency and stability.

Betaine is also known as trimethylglycine.

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Trehalose

Humectant, Moisturising

Trehalose is a disaccharide made of two glucose molecules (glucose is sugar!). Trehalose is used to help moisturize skin. It also has antioxidant properties.

As a humectant, trehalose helps draw moisture from the air to your skin. This helps keep your skin hydrated.

Due to its antioxidant properties, trehalose may help with signs of aging. Antioxidants help fight free-radical molecules, unstable molecules that may damage your skin.

In medicine, trehalose and hyaluronic acid are used to help treat dry eyes.

Some animals, plants, and bacteria create trehalose as a source of energy to survive freeze or lack of water.

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Glucose

Humectant

Glucose is a simple sugar (a monosaccharide). In skincare, it is mostly a humectant and skin conditioning agent.

Mechanistically, it has multiple hydroxyl groups that hydrogen-bond to water. This pulls moisture into the upper layers of skin to keep the surface soft and hydrated.

It's worth knowing sugars are already a natural component of the skin's NMF (natural moisturizing factor) so it's a molecule that your stratum corneum is well-acquainted with.

Just so you know, glucose is hydrophilic (water-loving) and the stratum corneum is a strong barrier to hydrophilic compounds. This just means penetration is slow and most of the action is happening on the surface.

Gram-to-gram, glucose is not as efficient as a humectant as glycerin. This is why you'll likely see glycose paired with stronger humectants for a bigger hydration payoff.

In skincare, glucose is typically derived from corn or other starch sources.

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Mannitol

Humectant, Masking, Moisturising

Mannitol is a sugar alcohol. It is a humectant and moisturizes the skin. In vitro (not tested on a living organism), mannitol displays antioxidant properties.

When found in aqueous solutions, mannitol tends to become acidic. This is because it loses a hydrogen ion. This is why mannitol can often be found with pH adjusting ingredients, such as sodium bicarbonate.

Fun fact: Mannitol can be found in foods as a sweetener. It can be naturally found in mushrooms, algae, fruits, and veggies.

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Maltitol

Humectant, Masking, Moisturising

We don't have a description for Maltitol yet.

Cellulose Gum

Emulsion Stabilising, Masking

Cellulose Gum is a water-soluble polymer that comes from cellulose. It is used to change the texture of a product and to help stabilize emulsions.

As an emulsifier, cellulose gum specifically thicken the texture of water-based products.

This ingredient is considered hypoallergenic and non-toxic. Cellulose Gum can be found in cosmetics, food, and other household goods such as paper products.

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Glycosyl Trehalose

Emulsion Stabilising

We don't have a description for Glycosyl Trehalose yet.

Hydrogenated Starch Hydrolysate

Humectant

Hydrogenated Starch Hydrolysate is a made up of a mixture of sugar alcohols (like sorbitol) and is created by hydrogenating corn, wheat, or potato starch.

It acts as a humectant and draws water to the skin to keep it hydrated. Generally, this is a well-tolerated and non-irritating ingredient.

Dextrin

Absorbent

Dextrin is used to thicken a product and helps bind ingredients together. It is created from starch and glycogen.

As an emulsifier, dextrin prevents ingredients from separating. This helps elongate a product's shelf life.

Studies show coating UV filters with dextrin prevents these ingredients from being absorbed. This helps UV ingredients last longer on the skin.

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Glycine

Buffering, Skin Conditioning

Glycine is the smallest amino acid and a key building block of collagen. It's part if your skin's Natural Moisturizing Factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.

A study from 2022 found that an amino acid complex featuring taurine, arginine, and glycine significantly reduced skin irritation, improved redness, and accelerated the skin repair process.

Pullulan

Pullulan is a low viscosity polysaccharide (a long chain carbohydrate) with binding and film forming properties when dissolved in water. It is used to create a "silicone-like" or silky feel in cosmetics without adding viscosity.

According to a manufacturer, this ingredient's ability to easily dissolves makes it a great carrier for active ingredients.

Due to it being edible and tasteless, you'll likely find this ingredient in breath freshener strips. This ingredient is produced from the starch of the fungus, Aureobasidium pullulans.

Pullulan is stable over a broad-range of pH.

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Dextran

Dextran is a sugar (polysaccharide) with skin hydrating properties.

Fun fact: Louis Pasteur first discovered this ingredient as a microbial product in wine.

Alanine

Masking, Skin Conditioning

Alanine is an amino acid and is already found in the human body. Our skin uses alanine to build collagen, elastin, and keratin.

Serine

Masking, Skin Conditioning

Serine is a non-essential amino acid (your body makes it on its own!). It is a major player in your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.

Serine is one of your NMF's most abundant components that works as a skin-identical humectant. Its hydroxyl group grabs onto water molecules to boost hydration without any heaviness or occlusion.

Research on a hydrogel with serine confirmed this serine got delivered to your stratum corneum and demonstrated enhanced skin moisturization.

Interestingly serine also helps your skin produce filaggrin, a protein that keeps your skin barrier strong and used to create collagen.

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Valine

Masking, Skin Conditioning

Valine is an essential amino acid. It is used by our bodies for tissue repair and muscle growth.

An essential amino acid is one in which our bodies cannot naturally produce so we must get them through diet. Foods such as eggs, dairy, red meat, and fish contain valine.

This ingredient can either be derived from an animal product or be synthetically created.

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