Arian Mowlavi, MD, FACS (license on probation) says:A Brazilian butt lift can be via 1) butt implants-silicone 2) fat grafting (from your abdomen/ flanks/ thighs/ elsewhere) 3) both. As far as max size, you need more fat on your body to graft it to your butt. If you want silicone, you could use a bigger size if your skin elasticity allows it. ...