Natural glycerin is derived from fats and oil such as coconut oil or palm oil. It can also be made from animal fat so if you are concerned about that you should look for “vegetable glycerin”. Synthetic glycerin is derived from petroleum. Most glycerin worldwide comes from natural sources.
Glycerine is hygroscopic, this means that it can attract and hold water molecules from the surrounding environment. This also means it is a humectant, it helps to retain moisture. The key benefits of glycerine for hair are:
Interestingly, did you know that if glycerin is left in an open unsealed jar or container it would continue too attract water molecules until it contained 20% water? I find that fascinating!
Glycerin can draw moisture out of hair so it is ideal to keep the volume of glycerin in any leave-on formulation under 10%, 5% and under is even better. If you are going to be rinsing the product off as with a shampoo or conditioner then you can add more if you wish.
You might also like:
The Disadvantages Of Glycerine For Natural Hair?
Ref. wisegeek, wikipedia, blackgirllonghair