Glycerin: Fall and Winter Hair Care
There is no scientific work that I can quote because no one as yet has directly studied that. However, glycerin is a humectant and as far as those go, glycerin is a very good one. This means it draws water to itself and is more stable with water present than without it.
If you did science in high school you may recall that in chemistry, the more stable a substance is, the less likely it is to change unless you inject in a large amount of energy. Therefore, glycerin bound to water is not easily going to give its water.
Therefore my conclusion is that glycerin is fine to use all year round. I do think that glycerin does have many stages depending on how much or little is on hair (it can feel good, sort of dry, sticky or mushy). It is definitely not the easiest product to use because results are variable so you may hate it one day and then love it the next.
I really highly recommend what I refer to as the Oyin method. Oyin makes a lot of products with glycerin and gave this helpful suggestion - try steaming your hair. This does not mean buy a streamer but rather do not cover your hair while you take your shower or bath and allow the steam to bind to the glycerin or glycerin product.
For more tips see this older post on how to get the most from glycerin - Troubleshooting with glycerin
Do you have issues with glycerin in the winter and have you tried the Oyin method?