Really good results with Juvederm XC. Metabolizes slowly but doesn't last as long as I would like (a few months).
Tell tale signs of injection (the two bumps at the top of the upper lip. I use an entire syringe in my upper lip, but have had good results using one third of a syringe in just the middle underneath the philtrum.
My lips are naturally full so this just makes them look fuller and poutier.