Nanofat and microfat: the differences and the current evidence

How do nanofat and microfat differ?

All fat grafting involves taking your own fat and moving it to another area, but how the fat is used depends on how finely it is broken down. Microfat is fat harvested with a thin tube and transferred in small clusters, and it is mainly used to restore volume to hollow areas of the face. A 2015 review considered that adding fat appropriately to a face that has lost volume because of age or disease can bring marked and long-lasting improvement ^[6].

Nanofat is made by processing harvested fat into small particles less than 0.1 mm in diameter, and it is described as containing high concentrations of stem cells and growth factors ^[1]. A 2023 review summarized that nanofat is currently used mainly for cosmetic purposes, to make the skin, especially facial skin, look younger and to improve its appearance ^[1].

A similar approach, in which fat removed by liposuction is centrifuged and emulsified to concentrate it into a small volume of liquid rich in progenitor cells (lipoconcentrate), has also been described ^[4]. Because there are several kinds of processed fat with similar names, a 2019 review focused on clarifying the terminology, treating finely fragmented fat (micro-fragmented fat) in the same category as nanofat ^[5]. During a consultation, it is more accurate to check how the fat will be processed and for what purpose it will be injected than to go by the name.

What is it used for?

A 2023 review summarized that nanofat may be used widely for fine lines and wrinkles, acne scars, sun-damaged skin, scar healing, and hair loss treatment ^[1]. A 2019 review also examined both preclinical and clinical findings on cosmetic uses of fat-derived components such as nanofat, stromal vascular fraction, and adipose-derived stem cells, including hair growth, scar reduction, and facial rejuvenation ^[5].

For facial scars, an approach combining microfat grafting, injections of concentrated fat liquid, a procedure that releases the tethering under the scar (subcision), and supplementation with platelet-rich plasma has been described as one that can be used to treat most facial scars ^[4]. This publication presents the authors' own treatment method and indications, and its research summary does not report any study results comparing it with other treatments ^[4].

What does "rich in stem cells" mean?

Fat tissue is easy to obtain and access, so it has been called a stem cell depot ^[3]. A 2021 review explained that components obtained from fat tissue have properties that reduce inflammation and fibrosis (scarring), suppress cell death, and regulate immune responses ^[3]. The fact that fat-derived stromal cells trigger a repair response at injured sites, remodeling the extracellular matrix (the framework around cells) and increasing the formation of new blood vessels, was presented as the reason for the expectations placed on nanofat ^[3].

However, these explanations mainly describe how things work at the level of cells and tissues. Whether effects seen in the laboratory or in animals appear to the same extent in human skin needs to be confirmed separately, and the 2023 review also stated that further research is needed to evaluate long-term effectiveness and safety ^[1].

A caution when applying research on medical conditions to cosmetic treatment

Fat grafting is also being researched as a treatment for medical conditions. A 2015 publication presented, as a new and promising treatment, the authors' approach of using fat grafting on the face and fat-derived stromal vascular fraction on the hands in patients with systemic sclerosis, a rare autoimmune disease in which the skin hardens and small blood vessels are damaged ^[7]. There is also a review that critically examined the current evidence for stem cell-based regenerative treatment of androgenetic alopecia (pattern hair loss) ^[8].

Because these studies involve patients with specific conditions, their results cannot be applied directly to cosmetic procedures in healthy people. Being considered promising for treating a disease does not mean that a treatment improves skin texture or wrinkles.

How far has the evidence come?

A 2020 review explained that facial fat grafting involves small volumes, but that unsatisfactory survival rates have made results difficult to predict, led to multiple procedures, and sometimes caused complications ^[2]. It stated that adding stem cells, processed fat products, or platelet concentrates may improve fat survival, but that randomized controlled clinical trials are needed to establish the safety and effectiveness of each technique and who it is suitable for ^[2].

Regarding nanofat, a 2021 review also stated that guidelines and preparation methods for its various clinical applications have not yet been standardized ^[3]. The 2023 review regarded nanofat as a safe and minimally invasive method of tissue regeneration, but added that more research is needed to evaluate its long-term effectiveness and safety ^[1]. It is most accurate to understand the current evidence as being at the stage of showing potential.

Recovery and what to check during your consultation

Nanofat and microfat also require fat to be harvested, so both the harvesting area and the injection area may swell and bruise. The recovery period and the number of sessions needed vary depending on your goal, the area, and the condition of your skin. It is a good idea to first agree with the specialist who examines you in person on the range of change you can expect.

• Whether the goal is restoring volume or improving the skin
• How the fat will be processed and what will be added to it
• The pros and cons compared with other treatments for the same goal
• The possibility of additional procedures and possible complications