I have injected both Juvederm and Restylane fillers in the lips. I find the Retylane Refyne to be the best for lip augmentation. It does some swelling (usually about 24 hours) but, but overall, I think it causes less swelling than Juvederm and gives a getter result. On the spectrum of Flexibility vs. Stiffness, Restylane Refyne is very flexible, making it a good choice for the lips. I wouldn't use it for building up cheeks or addressing nasolabial folds. For those areas, I personally prefer Radiesse (a calcium hydroxyappetate filler, not a hyaluronic acid.) Another interesting option for lips: Belotero. If someone wants definition to the edge of their vermilian border or just a juicier, moister look to the lip without large volume added, I choose Belotero. I hope that helps.