humectant

Propylene Glycol

INCI: PROPYLENE GLYCOL

What is it?

Propylene glycol is made by reacting propylene oxide with water under heat, an entirely petrochemical process. A smaller, newer bio-based supply also exists, made by chemically converting plant-derived glycerol (a biodiesel byproduct) rather than fermenting it. On skin, it works as a straightforward hygroscopic hume...

How is it used?

Add it to the water phase. It's not particularly heat-sensitive and is often used to pre-dissolve preservatives or actives before adding them to the main batch.

Forms

Available forms and grades affect how this ingredient behaves and how it should be selected for a formula.

Appearance

Color, texture, and physical characteristics can vary between suppliers and product grades.

Usage rate

Recommended incorporation levels depend on product type, supplier guidance, and the intended result.

Why we use it

Formulators choose this ingredient for specific performance, sensory, and stability benefits.

Strengths and limitations

Its advantages, compatibility considerations, and practical tradeoffs should be weighed during development.

Alternatives and substitutions

Possible replacements depend on the ingredient's role, desired skin feel, and formulation system.

Storage and shelf life

Appropriate storage conditions help protect quality and performance throughout the ingredient's usable life.

Propylene Glycol

What is it?

How is it used?

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