Cosmetic Ingredient Guide

Understanding the formulation of makeup products. This directory explains the commonly understood cosmetic purposes of various ingredients. Note: This information is for educational purposes and does not constitute medical advice or safety guarantees.

Glycerin

What it is:

A naturally occurring alcohol compound and a humectant.

Why it is used:

It is commonly used to attract and retain moisture in the skin, preventing formulas from drying out and helping makeup sit more comfortably on the surface.

Commonly found in:

Liquid foundations, primers, setting sprays, and cream blushes.

Mica

What it is:

A group of silicate minerals that naturally occur in various types of rock.

Why it is used:

When ground into a fine powder, mica reflects light. It is commonly used to provide a shimmering, luminous, or pearlescent finish to cosmetics.

Commonly found in:

Highlighters, eyeshadows, illuminating primers, and setting powders.

Iron Oxides

What it is:

Chemical compounds composed of iron and oxygen (often synthetically produced for cosmetic purity).

Why it is used:

They act as primary mineral pigments. By mixing red, yellow, and black iron oxides, formulators can create nearly any human skin tone shade.

Commonly found in:

Foundation, concealer, bronzer, and brown/black mascaras.

Titanium Dioxide

What it is:

An inert earth mineral.

Why it is used:

It is a brilliant white pigment that provides high opacity. It is commonly used to lighten the shades of other pigments and increase the coverage (opacity) of a formulation. It also reflects UV light, though cosmetic amounts do not replace dedicated sunscreen.

Commonly found in:

Full-coverage foundations, concealers, pressed powders, and sun protection products.

Silicones (e.g., Dimethicone)

What it is:

Synthetic polymers composed primarily of silicon, oxygen, and carbon.

Why it is used:

They provide a unique "slip" or smooth texture, allowing products to glide easily over the skin. They can help temporarily fill in fine lines and create a water-resistant, flexible barrier.

Commonly found in:

Pore-filling primers, liquid foundations, and long-wear lipsticks.

Waxes (e.g., Carnauba, Beeswax)

What it is:

Organic compounds that are solid at room temperature but pliable when warm.

Why it is used:

Waxes provide structure, stability, and adherence. They help products stay in solid stick forms and aid in coating and clinging to surfaces, like eyelashes or lips.

Commonly found in:

Lipsticks, lip liners, mascaras, and eyebrow pencils.