As an absorbent, alumina can give a mattifying effect. It is used in mineral sunscreens to help coat nano-sized filters, such as titanium dioxide. By increasing the size of the UV filters, these ingredients stay on the skin for a longer time. By coating small sized ingredients, alumina helps thicken a product.

Alumina may be used as an abrasive, or exfoliant.

Alumina is naturally occurring in the mineral corundum. Certain varieties of corundum create rubies and sapphires. Corundum is also the crystalline form of alumina.

Learn more about Alumina

Butylene Glycol

Humectant, Masking, Skin Conditioning

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Learn more about Butylene Glycol

Cyclopentasiloxane

Emollient, Skin Conditioning, Solvent

Cyclopentasiloxane, or D5, is a silicone used to improve texture of products and trap moisture.

D5 is considered lightweight and volatile. Volatile means it evaporates quickly after application. Once evaporated, D5 leaves a thin barrier that helps keep skin hydrated.

It is also an emollient. Emollients help soften the skin and prevent water loss. Silicones create a silky texture in products. D5 helps other ingredients become more spreadable.

Studies show D5 is safe to use in skincare products. We recommend speaking with a skincare professional if you have concerns.

Learn more about Cyclopentasiloxane

Dimethicone

Emollient, Skin Conditioning, Skin Protecting

Dimethicone is a type of synthetic silicone created from natural materials such as quartz.

What it does:

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

Learn more about Dimethicone

Disteardimonium Hectorite

Stabilising

Disteardimonium Hectorite comes from the clay mineral named hectorite. It is used to add thickness to a product.

It can also help stabilize a product by helping to disperse other ingredients.

Hectorite is a rare, white clay mineral.

Learn more about Disteardimonium Hectorite

Glycerin

Humectant, Skin Conditioning, Skin Protecting

Glycerin is already naturally found in your skin. It helps moisturize and protect your skin.

A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.

As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.

Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.

Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.

In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.

This ingredient is organic, colorless, odorless, and non-toxic.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

Learn more about Glycerin

PEG-10 Dimethicone

Skin Conditioning

Peg-10 Dimethicone is silicone with conditioner and emulsifier properties. It mostly acts as an emollient in skincare and and humectant in haircare.

According to the manufacturer, acidic formulations decrease the stability of this ingredient. It works best in neutral or near neutral formulations.

Phenoxyethanol

Preservative

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Phenyl Trimethicone

Skin Conditioning

Phenyl Trimethicone is a silicon-based polymer. It is derived from silica.

Phenyl Trimethicone is used as an emollient and prevents products from foaming.

As an emollient, it helps trap moisture in the skin. It is considered an occlusive.

Learn more about Phenyl Trimethicone

Polymethylsilsesquioxane

Polymethylsilsesquioxane is a silicone used as a film forming agent.

When applied to the skin, this ingredient creates an invisible film on the surface. This film still allows oxygen to pass through, but prevents moisture from escaping. This can help condition and hydrate the skin. It also leaves a silky feel when applied.

Polymethylsilsesquioxane has not been shown to clog pores. It has been deemed safe to use up to 55%, but most cosmetics use much less.

If you have concerns about using this ingredient, we recommend speaking with a professional.

Learn more about Polymethylsilsesquioxane

Titanium Dioxide

Cosmetic Colorant, UV Absorber, UV Filter

Titanium Dioxide is a mineral (or physical) sunscreen ingredient that provides broad-spectrum protection by blocking both UV-A and UV-B rays.

It sits on the skin’s surface and primarily reflects and scatters UV light and also absorbs some of it.

This makes the line between “mineral” and “chemical” sunscreens a bit blurry, but in skincare labeling, Titanium Dioxide and Zinc Oxide are the two ingredients officially classified as mineral filters.

Because it’s non-irritating, Titanium Dioxide is often recommended for sensitive or acne-prone skin.

Thanks to modern production methods, nano-scale or fine-grade Titanium Dioxide is now widely used in cosmetics to reduce white cast and improve texture.

Despite its small particle size, studies show that Titanium Dioxide, even in nanoparticle form, is not absorbed into the skin.

Learn more about Titanium Dioxide

Trimethylsiloxysilicate

Emollient, Skin Conditioning

This silicone is an emollient. Emollients create a thin film on the skin to prevent moisture from escaping.

It is not soluble in water and helps increase water-resistance in products.

According to a manufacturer, it can blend seamlessly with silicone oils, such as Cyclopentasiloxane.

Learn more about Trimethylsiloxysilicate

Water

Skin Conditioning, Solvent

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. Stay hydrated!

Learn more about Water

Iron Oxides

This ingredient is a combination of red, black, and yellow iron oxide pigments. This combination of colors is usually found in foundation, because it results in a "skin" color.