Fat grafting is a surgical procedure that transfers fat from one part of your body to another. A surgeon removes fat through liposuction, processes it, and then injects it into an area that needs more volume, whether that’s your face, breasts, buttocks, or hands. Because the fat comes from your own body, it’s called “autologous” tissue, which means your immune system won’t reject it the way it might react to a synthetic implant or foreign material.
The procedure has become one of the most versatile tools in both cosmetic and reconstructive surgery. It restores volume lost to aging, fills in contour defects from injuries or surgery, and can even improve the quality of overlying skin thanks to stem cells naturally present in fat tissue.
How the Procedure Works
Fat grafting follows three distinct steps: harvesting, processing, and injection. First, a surgeon uses liposuction to collect fat from a donor site on your body, typically the abdomen, flanks, or thighs. Research comparing these five common donor areas found no meaningful difference in graft quality or survival between them, so the choice usually comes down to where you have enough fat to spare and what’s easiest to access safely.
Once harvested, the fat needs to be cleaned and concentrated before it can be injected. Several processing methods exist. The most well-known is the Coleman technique, which spins the fat in a centrifuge to separate it into three layers: oil from damaged cells on top, usable fat in the middle, and blood and fluid on the bottom. The oil and fluid are discarded, leaving behind the concentrated fat cells ready for injection. Other approaches include rolling the fat across cotton gauze to absorb excess fluid, letting gravity separate the layers naturally, or washing and filtering the fat through membranes. All of these aim for the same goal: isolating the highest concentration of healthy, viable fat cells.
The final step is injection. The surgeon places fat in small amounts throughout the target area using a blunt-tipped cannula. Distributing the fat in tiny droplets across multiple tissue layers is critical. Each injected fat cell needs to be close enough to your existing blood supply to survive, so packing too much fat into one spot starves the cells in the center and leads to complications.
What Happens to the Fat After Injection
Not all of the transferred fat survives permanently. Clinical studies report retention rates ranging from 30% to 70% of the injected volume, which is why surgeons often slightly overfill the area, knowing some fat will be reabsorbed. The wide range depends on technique, the recipient site, and individual biology.
A freshly placed fat graft develops three distinct zones. The outer layer, closest to your existing blood vessels, survives intact. An intermediate zone contains damaged cells that can regenerate. The innermost zone, farthest from blood supply, dies off. On the first day after injection, the fat cells enter an ischemic phase with no blood flow. Your body sends immune cells to clean up damaged tissue. By the fourth day, new blood vessels begin growing into the graft from surrounding tissue. This process of new vessel formation is what ultimately determines how much fat survives long-term.
The fat that does establish a blood supply and survives the first few months is considered permanent. It behaves like normal fat tissue from that point forward, meaning it will grow or shrink if your weight changes significantly.
Boosting Survival With Enriched Techniques
Because unpredictable retention has always been fat grafting’s biggest limitation, surgeons have developed enhanced versions of the procedure. The most studied is cell-assisted lipotransfer (CAL), which enriches the fat graft with additional stem cells extracted from a separate portion of the harvested fat. A meta-analysis comparing CAL to standard fat grafting found that enriched grafts retained about 71% of their volume on average, compared to 48% for conventional grafts. Facial fat grafts showed even better results: 77% retention with CAL versus 51% without.
Another approach uses platelet-rich plasma (PRP), drawn from your own blood, to boost graft survival. PRP-assisted grafts showed retention rates of roughly 70% versus 40% for standard grafts. Both CAL and PRP techniques do carry a higher rate of minor complications, so the decision to use them involves weighing improved volume retention against a somewhat longer, more complex procedure.
Common Uses
Facial rejuvenation is one of the most popular applications. As you age, the fat pads in your face thin and shift downward, creating hollow temples, flattened cheeks, and deeper lines around the nose and mouth. Fat grafting restores this lost volume. Common injection sites include the temples (which may need 8 to 15 mL of fat when severely hollow), the cheeks, the area around the eyes, the nasolabial folds, and the lips. Each zone receives a different volume based on how much fullness is needed.
In breast surgery, fat grafting serves both cosmetic and reconstructive purposes. Women who’ve undergone lumpectomy or mastectomy for cancer can use fat grafting to fill contour irregularities or add volume to a reconstructed breast. One concern that lingered for years was whether injecting fat near previously cancerous breast tissue could trigger recurrence. A large study of nearly 4,700 breast reconstruction patients found no increased risk of lymph node spread, distant metastasis, or death among those who received fat grafting compared to those who did not.
Beyond the face and breasts, fat grafting is used to rejuvenate aging hands, smooth depressed scars, correct contour defects after liposuction or trauma, and add volume to the buttocks (sometimes called a Brazilian butt lift).
Risks and Complications
Fat necrosis is the most common complication. It happens when transferred fat cells don’t receive enough blood supply and die, forming firm lumps under the skin. These lumps can sometimes calcify over time, which may show up on imaging and occasionally be mistaken for other abnormalities, particularly in breast tissue. Fat necrosis is more likely when large volumes are injected or when fat is placed in thick clumps rather than small, dispersed droplets.
Fat embolism, where injected fat enters a blood vessel, is rare but serious. This risk is one reason surgeons use blunt-tipped cannulas rather than sharp needles for injection. Other possible complications include infection, asymmetry, overcorrection or undercorrection, and contour irregularities at the donor site from liposuction. Because retention rates vary, some people need a second procedure to achieve their desired result.
Fat Grafting vs. Dermal Fillers
For facial volume restoration specifically, the main alternative to fat grafting is injectable dermal fillers. The two approaches differ in almost every practical way. Fillers are done in an office visit with minimal downtime. Results typically last up to two years before the filler is gradually absorbed and you need another round. Fat grafting requires a surgical setting and recovery time, but the fat that survives is permanent.
Fat is cheaper to obtain than manufactured fillers, and your body provides a nearly unlimited supply. It also carries stem cells that may improve skin quality in the treated area. The tradeoff is that fat grafting is more technically demanding. As the American Society of Plastic Surgeons notes, the procedure is “more technically demanding and unforgiving” than off-the-shelf fillers. The injection process also feels different: blunt cannulas create more of a pressure sensation compared to the fine needles used for fillers.
For someone wanting a subtle refresh with no downtime, fillers are the simpler option. For larger volume needs, long-term results, or reconstructive goals, fat grafting is generally the better fit.
Recovery Timeline
You’ll have two areas healing at once: the donor site where fat was removed and the recipient site where it was injected. Swelling at the injection site typically resolves within two to three weeks. The donor site takes a bit longer, with swelling lasting four to six weeks, though most of it clears by weeks three to four. Bruising at both sites is normal and usually fades within the first two weeks.
Most people return to desk work within a week, though strenuous exercise is typically off-limits for three to four weeks to protect both the healing graft and the liposuction site. Your final results won’t be visible right away. The initial fullness includes swelling and some fat that will be reabsorbed. By three to six months, the surviving fat has established its blood supply and what you see in the mirror is close to the permanent outcome.