Hi - I hadn't ever heard of this, and after doing some internet research I still can't find much. It does seem to be a fat soluble vitamin C compound, available in vitamin supplements and also skin creams. I'm not even sure if it's man-made or naturally occurring. I've always heard of vitamin C as water soluble, so you cannot overdose. I'd imagine that it would be possible to overdose on a fat soluble version, but that might require some high doses of the supplements that contain it.I'd be careful with anything containing vitamin C. In high doses (even the water soluble version) it can cause diarrhea, gas, and cramping. Make sure you don't use a supplement with much more than 100% of the USRDA for vitamin C if you have IBS.Best,Heather