Thank you for the question. Yes, generally speaking, it should be possible to exchange moderate profile breast implants to a high-profile breast implant. Ultimately, which operation you should undergo (if any) will depend mainly on your personal goals. If I were seeing you in consultation, I would ask that you communicate these goals in terms of goal photographs and/or computer imaging. Avoid the use of cup sizes as a reference point; this can be a source of confusion and miscommunication. My best advice: select your plastic surgeon carefully. Make sure that he/she has significant experience achieving the types of outcomes you will be pleased with. Then, communicate your goals carefully, as discussed above. Working together you will come up with a good plan to achieve your goals. You may find the attached link (dedicated to revision breast surgery concerns) helpful to you as you learn more. Best wishes.
with implants but unless there is a problem you are trying to address, why do it? Going to HP from Moderate means you want more projection BUT are accepting of a narrower base that translates to more space between the mounds and less side boob. If this is what you want, then the HP implant will help. But without knowing what your concerns are, its hard to say if you should do it since it adds costs and risks that could end up with contractures which would be awful.