Nanofat and microfat

What it is

Both start as the patient's own fat. Microfat keeps its fat cells and its tissue structure, so it adds volume where it is placed (PMID 33507247, PMID 39480647). Nanofat is made by pushing microfat back and forth between two syringes and filtering it; no living fat cells survive, but the stem cells do (PMID 23783059). Microfat suits adding volume; nanofat is used to improve the skin (PMID 39480647, PMID 23783059).

What nanofat carries is a mix of fat-derived stem cells, small vessel fragments, growth factors and fats that calm inflammation and scarring (PMID 39480647). Breaking the fat down raises proteins in wound-healing pathways and leaves the level of repair signals unchanged (PMID 35666150).

Fat injected into the skin was developed as an alternative to fillers placed in the skin (PMID 22745443). For dark circles under the eyes, fat with nanofat did better than platelet-rich plasma in a randomized trial (PMID 36735798).

Where it came from

From 1995 Guerrerosantos placed fat in thin rolls through fine needles into tissue with a good blood supply, so less of it would be absorbed (PMID 19336083). In 2012 Zeltzer described injecting fat into the skin itself with sharp needles (SNIF) to treat fine wrinkles (PMID 22745443).

In 2013 Atiyeh reviewed the "stem cell facelift" and found that the clinical evidence did not support its marketing claims (PMID 34085105). That year Tonnard introduced nanofat and showed in the laboratory that its stem cells grew and matured as well as those in ordinary fat (PMID 23783059). His group also added microfat to eyelid surgery to fill the hollows that removing tissue leaves behind (PMID 23515379).

Methods for delivery followed: fluid fat injected just under the skin and into the eye and mouth muscles (SEFFI) in 2015 (PMID 25911629), and nanofat needling in 2019, which uses a microneedling device to spread nanofat evenly through the skin (PMID 30921122). In 2025 an expert panel wrote the first agreed definition of how to make nanofat, and found that most uses still lack strong clinical evidence (PMID 40250993).

Who it suits

• Fine wrinkles around the eyes and mouth. Nanofat or fine fat injected into the skin reduced wrinkle depth and area (PMID 37822183, PMID 25911629).
• Sun-damaged skin. Microfat placed in the skin improved texture, color and wrinkle depth in photoaged faces (PMID 28526633).
• Scars. Scars are the most studied use of nanofat (PMID 40800046).
• Dark circles. Fat fills the groove under the eye and nanofat placed near the surface treats the color (PMID 36735798).
• Hollow eyelids and a visible lid-cheek border. Microfat with blepharoplasty fills the upper lid, the groove below the eye and the cheek (PMID 23515379).
• A long, thin upper lip. A lip lift shortens the lip and microfat restores its volume (PMID 30789473).
• Large hollows. Microfat, which keeps its fat cells, is suited to adding volume; nanofat has no living fat cells (PMID 23783059, PMID 39480647).

How it is done

Collecting the fat

• Fat is taken by liposuction from the abdomen, inner thigh or inner knee, then washed (PMID 32095390).
• Microfat comes through a cannula with many small side holes (PMID 33507247, PMID 25911629).
• Little fat is needed. Breaking fat down mechanically gave as many cells as enzyme processing from about a tenth of the fat (PMID 31454336), and low nanofat volumes were enough for some patients (PMID 42754699).

Making microfat and nanofat

• SEFFI uses two grades of fine fat: the finer one goes into the muscle around the eyes and mouth, the coarser one under the skin elsewhere (PMID 25911629).
• Micro-SEFFI is finer fat used without further processing; it keeps living fat cells and stromal cells (PMID 27241362, PMID 29905790).
• Nanofat is washed fat passed back and forth between syringes through a narrow connector and then filtered, as defined by the 2025 consensus (PMID 40250993).
• The connector matters: a wider connector broke fewer cells and kept more of them alive in the laboratory (PMID 35672247).
• Breaking fat down destroys the fat cells and leaves most stromal cells alive (PMID 29157877, PMID 31454336). One laboratory found far fewer living stromal cells in nanofat than in microfat (PMID 33507247).

Placing it

• Into the skin through a fine 27-gauge needle (PMID 37822183), or into the fat under the skin through a small cannula (PMID 32095390).
• By needling: a microneedling stamp spreads nanofat evenly into the skin (PMID 30921122), and adding a roller shortens the treatment (PMID 34566373).
• In layers: nanofat under the skin plus needling into the skin, with optional CO2 laser, in one session (PMID 42754699).
• On the skin: a nanofat cream applied after nonablative fractional laser (PMID 31504170).

Results and how long they last

Skin quality

The skin changes under the microscope more clearly than in photographs. Biopsies after nanofat show thicker skin with more collagen and elastic fibers (PMID 37400953, PMID 32095390), and in facelift candidates, sun damage in the elastic tissue decreased and new elastic fibers formed 3 months after fat with stromal cells (PMID 25811565). Clinical proof is thinner: a 2019 systematic review concluded that fat grafting and cell injections "hardly seem to improve facial skin quality" but are safe (PMID 31688753), and a 2021 review found well-controlled studies very scarce (PMID 34085105).

• Microfat in the skin reduced average wrinkle depth by 41% on skin imaging (PMID 28526633).
• Nanofat injected into wrinkles reduced their depth, area and volume at 7 months (PMID 37822183).
• Nanofat and stromal cell injections both lowered wrinkle scores, while skin thickness on ultrasound did not change (PMID 41811159).
• After a multilayer nanofat session, skin quality improved in every patient by the treating doctor's rating (PMID 42754699).
• Nanofat cream after fractional laser gave better wrinkles, folds and texture than laser alone in earlier patients (PMID 31504170).

How long it lasts

• Fat injected into the skin with sharp needles lasted more than a year (PMID 22745443).
• Microfat contouring held through follow-up of up to 5 years (PMID 19336083).
• Scar results are short term: high-quality trials found no lasting benefit beyond 12 months (PMID 40800046).

Scars and dark circles

• In a blinded randomized trial, the nanofat half of each abdominoplasty scar scored better on every measure at 6 months (PMID 41055340).
• Nanofat softened scars and made discoloration less visible, with high patient satisfaction (PMID 29365061).
• For dark circles, about 1 in 15 patients treated with fat and nanofat did not respond (PMID 36735798). With platelet-rich plasma, about half did not respond (PMID 36735798).

Enriched fat

• Fat enriched with the patient's own stromal cells had a survival rate of 77.6% at 6 months in a randomized trial (PMID 32269011). Plain fat grafts survived at 56.2% (PMID 32269011).
• Mechanically processed fat contains more of the cells and signals that build blood vessels, but clinical studies have not shown better graft survival (PMID 39150855).

Risks and how surgeons lower them

• Bruising and swelling. These are the most common effects after fat injected into the skin (PMID 22745443) and after microfat to the eyelids (PMID 23515379).
• Cysts and lumps from nanofat. The first nanofat series had no infections, fat cysts or granulomas (PMID 23783059), and a randomized trial found no oil cysts or fat necrosis on the nanofat side (PMID 41055340). Reviews report no serious complications (PMID 31688753, PMID 40800046).
• Oil cysts from fine fat. These occurred in about 3 in 100 SEFFI patients (PMID 25911629).
• Problems with facial fat grafting in general. Prolonged swelling, lumps and irregularities, and acne flare-ups are the most reported (PMID 36012947). Fat that grows, fat necrosis, cysts, lumps and asymmetry can need a second procedure (PMID 36012947). Published complication rates vary so widely that the true rate is unknown (PMID 36012947).
• Fat in a blood vessel (embolism). Microfat can travel in the arteries and veins of the face; one patient died of microfat embolism to the brain (PMID 34133713). The area between the eyebrows was the most common injection site in reported cases, and most cases ended in permanent blindness in one eye (PMID 34133713). Symptoms can appear at once or be delayed, no treatment has proven effective, and the authors call prevention the main protection (PMID 34133713).

Recovery

• After CO2 laser, microneedling and nanofat in one session, patients recovered in about 5 days on average and reported no pain (PMID 37089168).
• Nanofat after laser and microneedling sped skin healing on biopsy (PMID 37089168) and caused milder early inflammation than a growth factor product (PMID 41890322).
• After nanofat under the skin, results showed at 2 to 4 weeks and kept improving to 6 months (PMID 32095390).
• Tonnard reported the skin quality changes at 6 months (PMID 23783059).

With a facelift

• The lipo-facelift combines facial liposculpture with a SMAS facelift; skin blood flow improved, with follow-up up to 8 years (PMID 24142113).
• Microfat with stromal cells and platelet-rich plasma was placed under the eye and in the cheek during facelift or neck lift in patients over 55 (PMID 42582686).
• In that study the grafted volume fell to its lowest at 5 to 7 months and rose again by a year; there was no control group (PMID 42582686).
• Fat with stromal cells injected in front of the ear in facelift candidates reduced sun damage in the elastic tissue and formed new elastic fibers (PMID 25811565).
• Microfat is added to blepharoplasty to fill the eyelids and the lid-cheek junction (PMID 23515379), and to lip lifts to restore lip volume (PMID 30789473).
• Nanofat is also used to speed healing after laser resurfacing (PMID 37089168, PMID 31504170).

Questions to ask a surgeon

• Will you use microfat for volume, nanofat for my skin, or both? (PMID 39480647)
• Where will you take the fat from, and how much do you need? (PMID 32095390)
• How do you prepare the nanofat? (PMID 40250993)
• What change in my wrinkles or scars should I expect, and for how long? (PMID 40800046)
• How often do your patients get oil cysts or lumps, and how do you treat them? (PMID 36012947)
• Will you inject fat between my eyebrows, and how do you prevent fat from entering a blood vessel? (PMID 34133713)
• If you call this a stem cell treatment, what evidence supports that? (PMID 34085105)

Open questions

• Whether nanofat improves skin in controlled trials: reviews rate the evidence low (PMID 31688753, PMID 34085105, PMID 40250993).
• How many living cells nanofat holds: one study found a high cell yield (PMID 31454336), another a loss of living cells (PMID 33507247).
• What does the work: lipid mediators and proteins may matter more than cells (PMID 39480647, PMID 35666150).
• A standard preparation: connector size changes how many cells survive (PMID 35672247).
• Whether scar benefit lasts beyond 12 months (PMID 40800046).
• Nanofat compared with stromal cell enrichment (PMID 41811159, PMID 32269011).
• How often embolism and other complications go unreported (PMID 34133713, PMID 36012947).

Terms

• Microfat: fat collected through small side-hole cannulas that keeps intact fat lobules (PMID 33507247).
• Nanofat: emulsified and filtered microfat with no living fat cells (PMID 23783059).
• Emulsification: passing fat back and forth between syringes through a connector (PMID 35672247).
• SNIF: sharp-needle intradermal fat grafting (PMID 22745443).
• SEFFI: superficial enhanced fluid fat injection (PMID 25911629).
• Stromal vascular fraction (SVF): the non-fat cells of fat tissue, including stem cells and vessel cells (PMID 31454336).
• Adipose-derived stem cells (ADSCs): stem cells within fat (PMID 23783059).
• Nanofat needling: microneedling used to deliver nanofat into the skin (PMID 30921122).
• Cell-assisted lipotransfer: fat grafts enriched with SVF cells (PMID 32269011).
• Elastosis: sun-damaged elastic fibers in the dermis (PMID 25811565).

Papers