Is glycerin vegan? Why the honest answer is often "not sure

Glycerin (also written Glycerol or Glycerine) is one of the most common ingredients in skincare. It pulls water into the upper layer of the skin, keeps creams from drying out, and costs very little. It is also the single ingredient that most often stops us from calling a product vegan.

Where glycerin comes from

Glycerin is a by-product of splitting fats into fatty acids, which is how soap and many surfactants are made. The fat can be vegetable oil (palm, coconut, soybean, rapeseed), or it can be animal fat, mostly tallow. Glycerin can also be made synthetically from petroleum. All three give the same molecule, and the ingredient list uses the same word for all of them.

Most cosmetic glycerin today is plant-derived, especially in Europe, because vegetable oils are cheaper and more available. But most is not all, and a label that says Glycerin tells you nothing about the source.

Why we say not sure

Our vegan check reads the ingredient list. When every ingredient is plant, mineral or synthetic, we say yes. When we find an animal-derived ingredient such as beeswax, lanolin, carmine or milk protein, we say no. Glycerin belongs to a third group: ingredients that can be either. So do stearic acid, cetearyl alcohol, glyceryl stearate, lecithin and squalane.

For those, the only honest answer from the list alone is not sure, and we say exactly which ingredient caused it. If the brand marks the product as vegan on the pack, that settles it, and the answer becomes yes.

How to find out for a specific product

• Look for a vegan mark on the pack or the brand's website. The Vegan Society sunflower and PETA's vegan logo are the common ones.
• Check the brand's ingredient sourcing page or ask them. Most brands answer this question quickly.
• Some labels spell it out: Glycerin (vegetable derived) or Vegetable Glycerin. When we see that, we count it as plant-derived.

The bigger picture

A not sure on glycerin is not a hidden no. It is a gap in the information on the label, and it is the same gap for almost every cream on the shelf. If you are strict about sourcing, treat a vegan claim from the brand as the real answer, and treat the ingredient list as the place to rule out the clear animal ingredients.