I suggest reading ingredient lists.
A majority of lip products contain petroleum in some form, whether it be listed as petroleum jelly, petrolatum, mineral oil, paraffinum, or something else. Most of the stuff at the drugstore, including Chapstick, Blistex, Carmex, Softlips, and Lip Smackers all have it. If the product contains enough moisturizers, it might help trap some of those against your skin so they absorb, but if it doesn't, it will probably trap moisture out. When it comes down to it, petroleum cannot be absorbed by your skin/lips, so you need to make sure there are enough moisturizing ingredients that will do the job in spite of the petroleum forming a film on your lips.
MAC lipsticks, from what I can tell, are mostly waxes, which won't moisturize your lips. They probably contain enough oils to keep healthy lips in good shape, but if your lips are already dry and chapping, they won't heal them, and you would probably be lucky if they didn't get any worse.
The Dior Addict glosses, on the other hand, worry me - I can't find an ingredients list anywhere! If I'm paying $25 for a little tube of lip gloss, I would expect some ingredients so I know what the heck I'm paying for.
My recommendation is to try switching exclusively to all-natural lip balms for a bit and skip any other lip products until you can get your lips in better shape. Softlips came out with an all-natural variation awhile back (I found it at Target), and Lip Smackers just came out with one, too (spotted it yesterday at Walgreens). Also consider lipbalms from indie companies or Etsy shops; often they are based on a blend of good oils and waxes.
Try to avoid something that's going to be mostly wax, like beeswax lip balm. Waxes will coat your lips and possibly protect them, but they have little chance of absorbing.
My personal favorites: Coola LipLuxe and Aromaleigh Aromatherapy Lip Balm (
Aromaleigh Aromatherapy Lipbalm- *DISCONTINUED* INVENTORY LOW ON MANY VARIETIES (UPDATED!)).
I hope this helps in some way!
