Good morning. Thanks for sharing your concerns. I typically start my patients at 1 syringe. The risk with half a syringe is the impression of under- correction and not being able to achieve the patient's desired goal. You need a formal consultation to identify your goals and discussed options. Good luck, Dr. ALDO
Your lips are quite full, and depending on your goals, starting with 1/2 syringe for just the upper lip sounds very reasonable. More important than the brand or amount, is the approach & training of your physician injector.