Is It Ok to Inject a Double Amount of Filler into the Lips at a Time?

It is perfectly ok to note the amount of filler you had that gave you the desired result and duplicate it in one office visit for a future treatment. Lip augmentations are frequently performed conservatively, and it is not out of the ordinary to have a touch up. There are no additional risks related to the increased dose that are any different than the original treatment, provided the treatment follows a recommended dosage. I hope this helps, and I wish you the best of luck.

If you are achieving the desired outcome with 2mL's of Restylane each time, there is no reason why you couldn't do it again. It's unclear how long a dermal filler really lasts in the lip and peri-oral region but often, it doesn't last quite as long in this area.

     Injecting 2 of the Restylane syringes into the lips can be performed at the same time if you were happy with a one and one previously.  Kenneth Hughes, MD Los Angeles, CA

The amount of volume each person needs, and wants, is different. It is not unusual to use 2 cc's for lips. If the result is what you want, then consider returning for a touch-up before all the volume is lost. This way you keep the look you desire, and will still have some Restylane left in the lip to build on. It is likely that you will only need 1 cc at a time for maintenance. If wait and need two, it is fine to do 2 cc's. Most experienced injectors will do 1 cc the first time if you have never had lip enhancement before. This is to prevent over correction. You can always have more added, but removing too much volume is a harder problem.

Different people need different amounts of Restylane, or any other filler.  If 2 cc seemed to be the correct amount for your lips, it would be fine to have that injected at the same treatment session.  The amount used should not cause a higher chance of unevenness although it is possible that you may notice a bit more temporary swelling.