source: essentialhealth.com

So glycerin is one of those skincare and beauty product ingredients I've been on the fence about. Is it really that bad for you, or is it just some people being overly cautious? It's sometimes used as a preservative and sweetener. It's also a fairly common ingredient in lotions and serums, even in homemade recipes, so I wanted to find out more.

Glycerin is a by-product from soap manufacturing and is technically an alcohol. I went straight to the source on its toxicity: the National Institute of Health, which states that "osmotic effect of glycerin may also produce tissue dehydration and decreases in cerebrospinal fluid pressure." Just as I'd thought. Like petroleum, glycerin softens the skin and acts as a barrier -- but in doing so, it "hydrates" by drawing moisture from beneath your skin's surface. So any products using glycerin that claim to hydrate or moisturize aren't actually moisturizing or hydrating at all.

There is such a thing as vegetable glycerin (glycerol), which is a liquid derived from a slew of vegetable oils. According to Livestrong.com, ingesting certain types of vegetable glycerin can be unhealthy:

While most forms of vegetable glycerin have a relatively low toxicity, some forms, especially propylene glycol, can have toxic effects when consumed in high quantities. According to the World Health Organization, too much propylene glycol can cause excess lactate to build up in the bloodstream and can lead to coma, convulsions and cardiovascular problems such as heart attack. However, the amount required to cause these reactions is high, making an overdose unlikely.

Applied to the skin, vegetable glycerin seems relatively non-toxic, causing allergic reactions in the worst cases -- though I would still avoid propylene glycol if possible. But natural or "organic" beauty products containing other forms of food-grade vegetable glycerin are probably fairly harmless.

Do you use any products containing vegetable glycerin? Is there a marked difference in texture or hydration?