I would like to know why 800cc is the biggest in gel implants?

Based on studies showing increased complications with implants bigger than 800cc, that is what was approved for use in the United States.

Thank you for your question about breast implant sizes.  800cc is what the FDA determined to be the largest size for implants as larger implants can present a higher complication rate.  Some physicians however do offer overfilled saline breast implants, however this would require an in person consultation and thorough discussion of long term risks and benefits.  I hope this has been
helpful and I wish you all the best.
Brian S.
Coan, MD, FACS
Raleigh-Durham
Plastic Surgeon

Implants in this range have a significantly higher rate of complications. Thus, it was chosen to limit the volume at 800 cc. There are some physicians who will "overfill" saline implants, but this has significant long term negative effects on the breasts. Best of luck,
Vincent Marin, MDSan Diego Plastic Surgeon

Many of the regulations imposed upon breast implant manufacturers comes from the FDA. Larger silicone breast implants are utilized in Europe.  In our practice, assuming patients are good candidates, saline overfilled breast implants are utilized quite effectively. You may find the attached link helpful to you as you learn more. Best wishes.

That is the largest size that the American breast implant companies make. All sizes had to be approved by the FDA, and sizes larger than that had more long term risks and fewer patients who wanted them.