Ask Corn Allergy Girl: Glycerin

The Question

Hi there,  I was just diagnosed with a corn allergy and your website is so helpful.  Thank you for all the time and care you have put into sharing your knowledge!!  Question — I know some glycerin can be corn derived.  I have a hand cream that has glycerin and I emailed the mfr…they said the product is corn free and the glycerin is a synthetic form.  Does this answer the question?  I am not educated enough to know if this guy is not educated enough to answer me properly!!
Thanks so much.

The Answer

Hi Valerie,

Your instinct to question the accuracy of that answer is totally correct. It’s not usually that manufacturers are trying to lie to you, it’s just that they don’t really know enough about chemistry to be able to answer your questions. When people say an ingredient is synthesized, always ask: “Synthesized using what?” You can’t just create something out of thin air, after all. There must have been some starting materials.  If they say something generalized like “citrus fruit” or “plant cellulose,” ask WHICH fruit, WHICH plants. And then still try carefully. 🙂 
As it turns out, it is actually possible to synthesize glycerin from a non-corn source. Here’s the big secret of how I figured that out: I looked it up on Wikipedia. Under the section about production, they mentioned that it can be from vegetable fats or indeed that it can be synthesized. If you click on the links for the materials they list as the building blocks for synthesis, you’ll see they are all petroleum sources. That’s interesting though. I have literally never seen anyone say they use glycerin from that source. It’s always vegetable. 
Best of luck with your new diagnosis. It’s a wild ride, but if you just take it one step at a time you’ll be fine.