Study the Product
This is the first step that you should take before you look to buy it. There are going to be many varieties of the product that are available in the market. See what are the specific qualities of each one of them and select the one that suits your particular needs more.
It is quite likely that you will find vegetable glycerin in a pharmacy or a store. Since pharmacies are related with all kinds of medications, they are generally the place that will likely stock such products. Even if they do not have them in stock, they can certainly point in the right direction.
Skin Care Stores
There are stores that specifically sell skin care products. They have all kinds of skin related products and you should be able to find a variety of glycerin there. They should also be able to enlighten you on the various options that you have in the vegetable glycerin and what benefits they offer you.
There are a number of online stores for anything that you need. You can go to one that offers skin care products and look for the vegetable glycerin. This should do the job for you. You may actually find it a little cheaper as well in comparison with the price in the market.
Sites such as eBay carry just about every imaginable product. You can probably get a dozen different varieties on these websites and prices generally are great as well. You can also get them in bulk to save even more.