I've had my lips plumped several times before using restylane. I loved it! It lasts between 6-12 months. And unlike fat transfer and stuff like that, it's a slight change so it doesn't look like that fake duck lip thing! It just adds a bit of volume. BUT--fair warning-- it hurts bad!!! They'll numb your lips but it still hurts so bad!! But it's worth it
I worked at a dermatologist office so I got mine for free, but we charged $650 for a syringe of restylane and one syringe is more than enough. What I always did was have her inject half and then refrigerate the rest. Then I'd go home and wait for swelling to go down and decide if I wanted more and where I wanted it. Then go back the next day or two and have her inject the rest. You get so swollen when you do it that it's hard to see the actual results for a few hours. Hope this helps :]