Maybe you've lost a bit of volume over time, maybe you've just always wanted a boost lip-wise. Either way, lip fillers are the way to go if you've decided to take some steps when it comes to the size and symmetry of your pout.
The whole point for this treatment is for the lips to feel natural. You shouldn't feel any difference when kissing someone with filler, or your recipient shouldn't feel the difference after your treatment. There will be a little tightness after your session. However, this will go down within a few days.
Lip fillers are safe if a professional and credible practitioner is on the other end of the needle. This is one of those treatments you don't want to just find the cheapest without recommendation or doing your research first.
Most people come back somewhere between six months and a year - it depends on the look you're after, your budget, and how quickly your body metabolises the filler.
Your injector will give you advice that's specific to your situation, but as a rule, you'll want to stay hydrated, avoid the sun, exercise, smoking, and stay away from spicy or oily foods. Many clinics also recommend leaving three weeks between your filler appointment and any important events or flights. Also, remember that the initial fullness you see on the day will go down somewhat as the swelling recedes.