Each plastic surgeon will have their own technique of grafting fat. Most of the fat is typically grafted in the subcutaneous, fat layer and below the skin, as well as below the breast tissue. some surgeons may graft into the pectoralis muscle and some probably avoid this. There’s no documented issues reported with grafting into the pectoralis muscle to my knowledge. Delivering consistent quality, liposuction and fat transfer results is more difficult than most people realize. There is substantial difference in outcomes, depending on which provider you choose. During in person, consultations, ask each provider to open up their portfolio and show you their entire collection of before, and after pictures of previous patients who had similar body characteristics to your own. Always confirming that after pictures were taken at least 3 to 6 months from the date of the procedure. Early fat transfer results can look very impressive but do not in any way represent final results. Best, Mats Hagstrom, MD