According to the American Society of Plastic Surgeons, cosmetic treatment with fat injections involves the extraction of fat cells from the patient's abdomen, thighs, buttocks or elsewhere and reinjecting them beneath the facial skin. Most often used to temporarily improve the appearance of hollow cheeks, thin lips, frown lines, crows feet, or scarring, because the fat is taken directly from the patient's body, fat injections do not require FDA approval. Also known as autologous fat transplantations, microfat transplantations, fat grafting or microlipoinjections, fat injections are most appropriate for individuals who desire an all natural injectable filler.

Treatment with fat filler is usually performed in a doctor's office under local anesthesia. The surgeon begins by applying an antiseptic to both the area from which the fat will be removed and the area in which it will be injected. The fat cells are then removed with a syringe that is connected to a vacuum device. After the extracted fat is processed and purified it is injected into the target area. Depending upon the extent of treatment, the procedure can take anywhere from thirty to ninety minutes to complete.

Following the procedure, it is not uncommon for patients to experience swelling that may last for several weeks or months, as well as some bruising. According to the New Zealand Dermatological Society, complications which may arise as a result of treatment with a fat filler include undercorrection, overcorrection, clumping, accidental damage to the nerves or blood vessels, bleeding, infection, and scarring.

Treatment with fat injections is not permanent. Bodies reabsorb fat cells at a different rate, therefore results after treatment with fat injections may vary. Reports provided by the American Society of Plastic Surgeons claim, "though some patients have reported results lasting a year or more, the majority of patients find that at least half of the injected fullness disappears within 3-6 months" after which point a follow-up treatment is necessary to maintain results.

Although prices may vary depending upon the size of the area being treated, according to Press Enterprise, a Los Angeles based print and online news source, the average cost of treatment with fat injections is $1000.