If used properly when slugging before bed, it can do wonders for your skin!
Vaseline is all occlusive so it does provide any hydration or moisture but it does lock in all your products underneath it, so if you apply a moisturizer under vaseline, the vaseline will help you get the full benefits and as much hydration’s and moisture from your moisturizer as possible.
This can also backfire, for people who are acne prone/oily skin or use strong chemical exfoliants, trapping too much of the skins oils in the pots will results in breakouts, and trapping too much acids in the skin can result in irritation. The success of vaseline heavily relies of the individual and the products you use under it.