Adipose stem cells are multipotent cells found in fat tissue, and researchers study them as an alternative to bone marrow cells for tissue engineering. This page covers their biology, how they are identified, and their regulatory and evidence status.
They belong to the wider field described in what is regenerative medicine, where cells, materials and growth signals are tested for repairing tissue.
Origin of adipose stem cells
Adipose tissue is body fat, and it contains a mix of cell types: mature fat cells, blood vessel cells, immune cells and a smaller population of stromal cells that can divide and specialize. When scientists talk about adipose stem cells, they usually mean this stromal population after it has been separated from the fat and grown in a laboratory dish.
The modern research history is often traced to a 2001 study from a University of California, Los Angeles laboratory. The team processed human fat obtained by liposuction into a fibroblast-like population of cells, and reported that these cells could be maintained in culture for extended periods. In the same paper, the cells differentiated in vitro into fat, cartilage, muscle and bone-forming cells when given lineage-specific induction factors. The authors concluded that lipoaspirate contains multipotent cells and may be an alternative source to bone marrow-derived cells.
That finding mattered because fat is a tissue that can be collected in large amounts compared with bone marrow, so it offered researchers a convenient starting material for laboratory work.
Identification and definition of fat-derived cells
Different laboratories have used different methods to isolate and grow fat-derived cells, which makes studies hard to compare. To address this, the International Federation for Adipose Therapeutics and Science and the International Society for Cellular Therapy issued a joint statement in 2013 that set out minimal definitions for two things: the uncultured stromal vascular fraction, and the adherent stromal/stem cell population grown from it.
The stromal vascular fraction, often shortened to SVF, is the mixed collection of cells left after fat tissue is broken down and the fat cells themselves are removed. It is a heterogeneous mix, not a purified stem cell product. Cultured adipose-derived stromal and stem cells are what remains when the adherent cells from that mix are grown and expanded.
According to the same statement, cultured cells keep markers in common with other mesenchymal cells, including CD90, CD73, CD105 and CD44, and remain negative for CD45 and CD31. They can be distinguished from bone-marrow-derived cells by being positive for CD36 and negative for CD106. Laboratory differentiation assays toward fat, cartilage and bone complete the identification.
The more general definition for mesenchymal cells comes from a 2006 position statement. It proposed that such cells must be plastic-adherent in standard culture conditions and must differentiate to bone, fat and cartilage cells in vitro, along with a defined surface-marker pattern. Readers who want the wider picture can see the page on mesenchymal stem cells.
The 2013 statement was also candid about what was not yet settled. It noted that a characterization of the adipose-derived cell population with the greatest therapeutic potential remains unclear, and it described its own purpose as providing initial guidance and helping to develop international standards based on reproducible parameters. For a general reader, the takeaway is that even basic questions about which fat-derived cells matter most were still being worked out at the time.
- PLA cells differentiate in vitro into adipogenic, chondrogenic, myogenic and osteogenic cells: four lineages
- Lipoaspirate contains multipotent cells, possible alternative to bone marrow MSCs: multipotent
- Fat obtainable under local anesthesia with minimal discomfort: local anesthesia
- ASCs distinguished from bone marrow MSCs by CD36 positive, CD106 negative: CD36/CD106
- Population with greatest therapeutic potential remains unclear: unclear
Adipose cells compared with other stem cell types
Adipose stem cells are adult stem cells: they come from a tissue of a born person and are not derived from embryos. They are described as multipotent, meaning they can form a limited range of cell types, in contrast to pluripotent cells that can form nearly any cell in the body. The distinctions between potency levels are laid out in types of stem cells.
Compared with bone marrow-derived cells, the 2001 authors pointed to a practical difference: fat can be collected under local anesthesia with minimal discomfort, which they presented as an advantage. Their study did not test whether treatments built on these cells work. It showed that the cells could be isolated and could differentiate in laboratory conditions.
Laboratory research on fat-derived cells
Most published work on these cells is laboratory or animal research. A 2025 study of adipose-derived cells during bone-like differentiation noted that preclinical studies support their use for bone regeneration, healing and functional outcomes, and also stated that a deeper understanding of the molecular mechanisms underlying their biology is crucial. In other words, the authors themselves describe the mechanisms as incompletely understood.
Typical research questions include which signals push the cells toward bone, cartilage or fat, how the cells interact with the immune system, and how to prepare them consistently from one donor to the next. Answering them takes controlled experiments, and results in a dish or in animals do not automatically carry over to people.
Regulatory status in the United States
The US Food and Drug Administration treats most cell-based regenerative products as biologic products. On its consumer information page, the agency lists stromal vascular fraction (fat-derived cells) among unapproved products marketed as regenerative medicine therapies. It states that these products require FDA licensure or approval to be marketed, and that before approval they require FDA oversight in a clinical trial.
The same page says FDA has repeatedly notified manufacturers, clinics and health care practitioners of the need for Investigational New Drug applications. It also states that regenerative medicine therapies have not been approved for any orthopedic condition, such as osteoarthritis. Reported safety concerns that FDA lists for illegally marketed products of this kind include blindness, tumor formation and bacterial infections.
The status of a particular product can change over time, so readers should treat the agency’s own pages as the current source rather than a summary on any website.
The limits of clinical study evidence
A recent network meta-analysis of 11 RCTs (randomized controlled trials) of mesenchymal cells in knee osteoarthritis began from the observation that existing studies show conflicting results on the best dose and tissue source. That sentence is a fair summary of the field’s position: the questions are open, and different trials have used different cell preparations, doses and measures.
Because preparations vary, a result from one trial of one product cannot be assumed to apply to another. This is one reason the 2013 joint statement called for reproducible standards, and why regulators ask for trials conducted under oversight. Anyone weighing a treatment option should discuss it with a licensed physician who knows their medical situation.
Frequently asked questions
Are adipose stem cells the same as the stromal vascular fraction?
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No. The stromal vascular fraction is the uncultured mixture of cells released from fat tissue, while cultured adipose-derived stromal and stem cells are the adherent cells grown and expanded from that mixture, as the 2013 joint statement defines them.
How are adipose stem cells different from bone marrow cells?
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Both are mesenchymal-type cells that share many surface markers. The joint statement says cultured adipose cells can be told apart from bone-marrow-derived cells by positivity for CD36 and negativity for CD106.
Are fat-derived cell products approved by the FDA?
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FDA’s consumer page lists stromal vascular fraction (fat-derived cells) among unapproved regenerative medicine products that require licensure or approval, and clinical-trial oversight before approval.
Do adipose stem cells become any cell in the body?
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No. They are multipotent, and laboratory work has shown them forming fat, cartilage, muscle and bone-forming cells, a narrower range than pluripotent cells.
