Propylene Glycol is derived from vegetable glycerin or seaweed. The most common moisture carrying ingredient other than water used in cosmetics because it moisturizes better than glycerin. Is used as a wetting agent and surfactant which gives a product better absorption and helps provide superior glide of  your  product on the skin. Propylene Glycol is an emollient. A lot of people confus Propylene Glycol  with Ethyl Glycol which is used in anti-freeze and other chemical based products, but it is not. Propylene Glycol  penetrates the outermost layer of the skin cells and deliver other beneficial products deeper into the epidermis.

According to the AMA's committee on Cutaneous Health emollients do help make the skin feel softer and smoother, reduce roughness, cracking and irritation. And may possibly retard the fine wrinkles of aging and is used in more of your upscale products.