Ingredient
Propanediol
A humectant and solvent, frequently used as a plant-derived alternative to propylene glycol.
What it is there to do
Humectant
Draws water into the upper layers of the skin or hair.
Solvent
Dissolves and carries the other ingredients.
What we don't know
- Where it comes from — plant, mineral, synthetic — isn't recorded.
- No published rule in our reference names it. That is about the rules, not safety.
- How much of it is used in any particular product. We hold no concentrations at all.
This is information about an ingredient, not medical advice, and not a judgement about any product that contains it. Back to the reference.