What Is a BBL? How Fat Transfer to the Buttocks Works

A BBL, or Brazilian butt lift, is a fat transfer operation: fat is removed by liposuction from areas such as the abdomen, flanks or lower back, prepared, and then placed under the skin of the buttocks to change their shape and projection. No implant is used. Because the donor areas are slimmed in the same operation, a BBL is really liposuction and buttock contouring combined, which is why, for some patients, the change in waist-to-hip proportion can be as noticeable as the added volume.

This article explains what physically happens during a BBL, what becomes of the transferred fat, and how it differs from buttock implants and non-surgical options. It is a general explanation, not a medical assessment. For how the operation is planned and what the stay involves, see the main Brazilian butt lift (BBL) page.

The names people use#

You will see the same operation described in several ways:

• Brazilian butt lift or BBL, the everyday name;
• fat transfer to the buttocks or buttock fat transfer;
• gluteal fat grafting, the term surgeons and medical papers often use;
• autologous fat transfer, meaning the fat comes from your own body.

Despite the word "lift", a BBL does not lift or tighten sagging skin. The lifted look some patients notice comes from adding fullness to the upper part of the buttocks and slimming the waist and lower back around them. When loose skin is the main concern, a different operation is usually discussed.

How a BBL works: the three stages#

A BBL is done in one operation, usually under general anaesthesia, and it often takes a few hours depending on how many areas are treated and how much fat is moved. The treating surgeon decides every detail of the technique; the outline below is only meant to help you follow the conversation at your assessment.

Stage one: taking the fat#

Before surgery, the surgeon marks the donor areas and the parts of the buttocks to be shaped, usually while you stand. Fat is then removed by liposuction through small incisions, commonly from the abdomen, flanks, lower back, hips or thighs. These areas are chosen for two reasons: they hold enough fat to use, and slimming them improves the outline of the waist and back.

Stage two: preparing the fat#

Not everything removed by liposuction is usable. The harvested material contains fat cells mixed with fluid, blood and oil from damaged cells. Before it goes back into the body, it is processed to separate the usable fat from the rest. Surgeons use different methods for this, such as letting it settle, filtering it or washing it, and the choice is theirs.

Stage three: placing the fat#

The prepared fat is placed in small amounts through small incisions, building the planned shape gradually. Mainstream guidance is that fat goes only into the fatty layer under the skin, above the gluteal muscle, and not into the muscle. Large blood vessels run beneath and within the buttock muscles, and fat placed too deep can enter them, which is how the most serious BBL complication, fat embolism, can arise (see the risks section below). At the end, a compression garment is fitted over the liposuction areas.

What happens to the fat afterwards#

Transferred fat is a graft, not a filler. For the first days it has no blood supply of its own and relies on the surrounding tissue while new small blood vessels grow into it. Fat cells that connect to a blood supply in time tend to survive; those that do not are gradually reabsorbed by the body. Not all of the transferred fat survives, and how much does varies from person to person.

Because of this, the result changes over the first months:

• early on, the buttocks often look larger than they will finally be, partly because of swelling;
• over the following weeks and months, swelling settles and part of the fat is reabsorbed;
• the shape is usually judged after around three to six months, once things are more stable.

Surgeons plan for this loss when they decide how much fat to transfer, within the limits the tissue can safely accept. If more volume is lost than expected, a second session is sometimes discussed later, rather than overfilling in one operation.

The fat that survives is living tissue and behaves like other fat in your body. If you gain or lose a lot of weight, the buttocks tend to change with you, and they age along with the rest of your body. That is one reason surgeons usually prefer patients to be at a stable weight before surgery. Aftercare matters too: pressure on the buttocks and nicotine in the first weeks are widely thought to reduce how much fat survives.

Fat that does not survive does not always disappear cleanly. Sometimes it forms firm lumps (fat necrosis) or small oil cysts, which may soften over time or may need a doctor to look at them.

What a BBL can and cannot do#

A BBL works with the body you already have. It can:

• add projection and roundness to the buttocks, within the limits of your available fat;
• add fullness at the top of the buttock for a more lifted look;
• soften hollows at the sides of the hips (hip dips), although bone structure means they are often softened rather than erased;
• slim the donor areas, which often improves the waist-to-hip proportion.

It cannot:

• tighten or lift loose, sagging skin;
• add more volume than your usable donor fat allows, or more than can sensibly be placed in one session;
• change the width of your pelvis or the shape of your hip bones;
• promise perfect symmetry, because fat may not survive equally on both sides;
• replace weight loss, or reliably treat cellulite or stretch marks.

A natural-looking result depends on proportion more than size. Our guide on how surgeons plan a natural-looking BBL covers the shapes patients commonly ask for and their limits, and the BBL before and after gallery shows results on different bodies. Each photo shows one patient and does not predict your own result.

BBL, buttock implants and non-surgical options compared#

People looking at ways to add buttock volume usually weigh three routes. The table summarises the main differences in general terms; the treating surgeon advises which, if any, suits your body.

Both surgical options carry the general risks of surgery and anaesthesia, including blood clots, and the treating surgeon advises which risks apply to you.

One point on non-surgical options deserves a clear warning. Injections of liquid silicone or other materials not approved for buttock enlargement have been linked to serious harm, and health authorities in several countries warn against them. Many fillers are not approved for use in the buttocks either, so if an injectable treatment is offered, ask exactly what the product is and whether it is approved for that use.

Who a BBL may suit, and who may not#

A BBL is more likely to suit people in good general health, at a stable weight, with enough fat in areas such as the abdomen, flanks or lower back, who do not smoke or can stop well before and after surgery, and who want a proportionate change rather than a particular size. The treating surgeon makes the decision after reviewing photos and medical history.

It may not suit you, or you may be advised to wait, if you have very little donor fat, a high BMI, a history of blood clots or a clotting disorder, a medical condition that is not well controlled, or loose skin as the main concern. Surgeons also usually advise waiting if you are planning a pregnancy. Our article on who is a good BBL candidate goes through each of these points.

Skinny BBL and BBL for men#

A skinny BBL is the same fat transfer approach planned for lean people with little spare fat. Smaller amounts are taken from several areas, and the aim is shape and proportion rather than a large change in size. Our page on the skinny BBL explains where its limits lie.

Men have BBLs too, but the goals are usually different: more projection and a firmer outline while the hips stay narrow. Men often have less fat to spare, which affects how much change is possible. The article on BBL for men covers how the plan differs.

The main risks in brief#

A BBL is major surgery, and it is widely regarded as carrying a higher risk than many other cosmetic operations. The main risks include:

• fat embolism, a serious and potentially life-threatening complication, where fat enters large blood vessels and travels to the lungs; this is why the layer the fat is placed in matters so much;
• blood clots in the legs that can travel to the lungs;
• fluid collections (seroma), infection and wound-healing problems;
• fat necrosis or oil cysts, felt as firm lumps;
• asymmetry, dents or irregular contours in the buttocks or the donor areas;
• more volume loss than expected;
• changes in skin sensation and the general risks of anaesthesia.

Being a suitable candidate and having a surgeon who explains their method lowers some of these risks but does not remove them. Our guide on whether a BBL is safe and what lowers the risk explains what surgeons control, what you can check yourself and which questions to ask.

Recovery in brief#

The first days are usually the most uncomfortable, mainly in the liposuction areas, which tend to feel bruised and tight. A compression garment is worn over those areas, and short, regular walks are usually encouraged from early on to support circulation. For a period the surgeon sets, you are asked not to sit or lie directly on your buttocks, because pressure may reduce the blood supply the new fat depends on; many patients sleep on their front or side and use a cushion under the thighs when sitting cannot be avoided.

Swelling settles over the following weeks, sitting is reintroduced gradually as the surgeon allows, and strenuous exercise is usually delayed for several weeks. Time off work depends on your job and how much sitting it involves. Our guide to BBL recovery and long-term results sets out the timeline stage by stage.

If you are planning treatment in Turkey#

If you are thinking about having the operation in Turkey, our BBL procedure page covers the techniques, the length of stay and travel in more detail. Planning usually starts with photos and your medical history, which the treating surgeon at a contracted healthcare institution in Istanbul or Antalya reviews. If a BBL looks suitable, you receive a written treatment plan and a personal quote.

Plastic Surgery Turkey Group (PSTG) is a health-tourism intermediary. It coordinates consultations, the hotel, transfers, an interpreter, follow-up after you fly home and contact with your home doctor, while the surgeon decides everything clinical, including whether a BBL is right for you. Because long periods of sitting matter after this operation, the surgeon will also advise when it is reasonable to fly and how to lower the risk of clots on the journey.

If you would like to know whether a BBL could suit your body, you can send photos for a free, no-obligation assessment and take your time deciding.