17 years ago I had Alloderm put into upper and lower lip and nasolabial folds. At 49 I still have no lines in the upper lip, which had at 32 begun. The nasolabial folds were very helpful as well. It didn't make my lips look bigger, but it firmed up the pesky skin that wrinkles around the lips.
For more fullness I had a permanent make-up artist add color both in my lips and to the farthest point she could enlarge them with color without having the lips look weird...that was determined by drawing with lipliner until the perfect shape was found. I like it. It made the white "space" between my nose and upper lip look smaller.