I bought this when I was in Korea, it was the middle of winter and my lips dry and cracking. My lips are usually quite dry but not to that painful extent and I was desperate to heal them. I put this on and it just sat there on my lips, didn't moisturize at all. I was desperate, even applying facial moisturizers on my lips and thank God it actually worked. I tossed this lip sleeping mask in my MU pouch and ignored it until after my trip (I live in Singapore so it's humid and hot). My lips weren't so dry (due to the weather) but still not as supple as I would have liked it. I went on my usual lip balm before lipstick, lipbalm before bed routine. THEN I took this laneige baby out. I was shook, it made my slightly dry lips Fuller, plumper and more moisturized than before. I can actually see the difference when I'm putting my lipstick on during the day.
So yeah, I do like using this lip sleeping mask, took off a star cuz of my tub packaging instead of a tube. Just be warned, that it won't do u any good if your lips are super dry or cracking.