Are 500 Cc Breast Implants Too Big?

The right implant choice for you is a complex decision and it is not that easy.
This depends on the amount of natural breast tissue, the breast diameter, degree of constriction, implant material, implant shape, chest shape, etc.
In general, 500cc is a larger than average breast implant and would likely have the additiional concerns of increased risks of interference with nipple sensation as well as long term risks of ptosis and breast deformity.
I assume that you are thinking of saline because silicone does not come in 510.
In someone considering implants this large, I generally recommend a high profile silicone but this is an opinion an open to discussion.
You may want to consider a breast sizing kit or performing the rice test and then asking friends and family for their advice.

Is not what I think in terms of size that is most important, rather what your concept of beauty and proportion is, whether there will be unwanted attention, and if it affects your choice of clothes. It is very difficult to determine the exact size and shape implant you will require to best match your ideal breast image without an examination by a board certified plastic surgeon. Not just any board certified plastic surgeon, but one with many years of frequently performing breast augmentation surgery including different approaches, techniques and implant choices. This is because several measurements not to mention your breast characteristics are needed to determine the optimal implant size to obtain your goals. Without knowing these dimensions it would be difficult to make this determination. For example, the existing base width of your breast will determine, in many cases, the maximal volume per implant profile that you can accommodate. To illustrate; a 100 cc difference may make a significant difference with a narrow base width breast, but much less of a difference if you have a wide chest wall and wide breast “foot print”. Therefore, just because your friend may have a great result with let’s say a 350 cc implant to make her go from a “A” cup to a “C” cup size does not mean that you will have the same result with the same size implant. . Further simply placing implants in a bra to determine the size best for you is not always accurate as the bra often distorts the size, is dependent on the pressure the bra places plus the implant is outside your breast and not under it among other variables. Computer software morphing programs that automatically determine the best implant size can be helpful in some but not all cases (e.g. doesn’t work well in my experience with existing implants, sagging or asymmetric breasts). Using “want to be” photos however are useful if simply provided to the surgeon as I will further explain in the below link.

Choosing a breast implant size can be difficult as patient preferences differ widely, and patient opinions may change..  For this reason a careful and detailed discussion of  your desires is necessary. 

I find that patients are sometimes reluctant to ask for larger sized implants. 

If  there are post operative regrets about size it is usually that they wished they had chosen a larger implant.

Rather than cup size I suggest that you provide photos of the size and shape of the breasts that you want....a picture is worth a thousand words.

At your consultation your board certified plastic surgeon will examine you and discuss your options with you.