How long does the bruising from a BBL take to fade away?

Bruises may take 1 to 2 weeks before fading away following the surgery.Kenneth Hughes, MDLos Angeles, CA

Bruising and swelling are very common following BBLs. Not only on the buttocks but also on the areas where you had liposuction. And sometimes the colors of bruising are truly amazing. Purple, red, green, yellow. Some people bruise a lot. Some people bruise less. Your surgeon can give you medications and suggestions on how to minimize bruising and its important of course to stay away from medications that cause you to bleed (NSAIDs, Ibuprofin, etc...). Always discuss this with your surgeon pre and post surgery.
Most of the bruising fades over a couple of weeks. The swelling can persist for months. In my experience massage helps a great deal especially with the lumps and bumps that people experience post operatively.
Healing from a BBL can be a lengthy and graduate process, but I find that the vast majority of my patients feel that the ups and downs were worth it. 
I hope this helps.
Good luck and good health!

Thank you for the question.  Not to be evasive, but this can really vary person-to-person as well as how and how much fat grafting was performed. In general it can take 2-3 weeks.  Over the first week the bruising will start coming to the surface from deeper down, then it will start changing colors to green and yellow, and by 2-3 weeks should be mostly faded away.  At the same time, it is not unusual for some bruises to persist a bit long than this.  Hope that helps!