Un-petroleum jelly is the same as Vaseline except it isn't made with petroleum. So it's like a more natural Vaseline. But does the same thing.
Many think that petrolatum is harmful for your skin, but I kind of doubt that so many dermatologists would recommend it if it was harmful.
By the way I started just using Vaseline for the last 2 days mainly because I need to get my prescriptions filled. But my lips have looked and felt much better. I think because its much more moisturizing than my prescriptions. So I think I will stick to just Vaseline for a while, especially since I'm now of he opinion that its more about causing less trauma than actually healing.