This is a question I get asked by nearly all my clients and the answer is different each time as everyone is unique. It depends on several factors – your age, the treatment area, the natural deficit that we are trying to improve, your desired result, and overall budget.
0.5ml might be the perfect amount to subtly plump the lips, 1-2mls can restore mid-face volume loss and lift the cheeks so reduce nasolabial folds, whereas 3mls or more may be needed to redefine the jawline, chin and enhance the lower face.
Discussions during your consultation will help you know what is required and a treatment plan can be made. It is always better to start small, more can be added later. Also, my personal belief is that after a filler treatment, no-one should really be able to tell that you have had anything done but instead be complimenting you on how fresh and well you look.