“Also called glycerol and glycerin, vegetable glycerin is a water-soluble sugar alcohol that comes from a variety of plant oils, including soy, palm, coconut, and corn,” says board-certified dermatologist at Marmur Medical, Rachel Maiman, M.D. “It’s made by heating triglyceride-rich vegetable fats under pressure or combined with a strong alkali.” Animal-derived glycerin, on the other hand, comes from animal fats.
This heating process causes the glycerin to separate from the fatty acids and, mixed with water, forms an odorless, syrup-like liquid. But before you think about adding this syrupy potion to your meals, you should know that vegetable glycerin is uber-hydrating for the skin. In fact, it’s commonly used in skin care products to give you that soft, supple, dewiness you’ve dreamed of (more on this later.)
While vegetable glycerin and animal-derived glycerin have similar benefits, the notable difference between the two is that vegetable glycerin is always plant-based. “Glycerin is a general term for a type of sugar alcohol compound, which can be derived from either animal fats or plant fats,” Maiman says. “It can also be artificially synthesized in the lab.” (You also have a natural supply of glycerin in your body, which decreases over time; this is why many brands incorporate it into their products.)
Even though glycerin and vegetable glycerin can be used interchangeably, a brand that uses the vegetable-derived ingredient will likely make it clear on the label. If you’re not sure, look for vegan formulas or feel free to ask the brand directly about how they source their glycerin.