Thank you for your question.
I am 100% for fresh fat specially for a brazilian butt lift.
I personally do not think freezing fat and thawing it is good. It is better to harvest fresh fat for BBL.
You can not use frozen fat for grafting. The fat does not survive the freezing and thawing process. It is best to use fat obtained at the time of liposuction.
Earl Stephenson, Jr, MD, DDS, FACS
Studies on frozen fat are inconclusive currently. The percent take of frozen fat is likely less than fresh fat. If possible, use new fat.
I liposuction the fat and use the fat for transfer at the same time.
Kenneth Hughes, MD
Los Angeles, CA