Regenerative medicine, explained: exosomes, MSCs, secretome and Muse cells

Regenerative medicine studies how cells, and the signals they release, might help the body repair tissue. It is one of the most active areas of biomedical research and also one of the most heavily marketed. The same words get used for very different products, so it helps to know what each term actually means.

MSCs are cells found in bone marrow, fat, umbilical cord tissue and other sources. In the lab they can become bone, cartilage and fat cells, and they release signals that influence inflammation and immune activity. A 2019 review in npj Regenerative Medicine describes decades of work moving MSCs from cell biology toward clinical trials.

Most MSC uses remain investigational. In December 2024 the FDA approved the first MSC therapy, for a specific, serious complication of bone marrow transplant in children. That approval is narrow and does not extend to wellness or anti-aging uses. Our MSCs page covers more.

Exosomes are tiny vesicles that cells release to carry proteins, lipids and genetic material to other cells. A 2020 review in Science describes them as a major channel of communication between cells and an active area of research for diagnostics and therapy.

There are currently no FDA-approved exosome products. The FDA has issued a public safety notification warning consumers about clinics marketing exosomes to treat a range of conditions. Read more on our exosomes page.

Secretome is the full set of molecules a cell releases, including growth factors, signaling proteins and vesicles such as exosomes. Researchers are studying whether the MSC secretome could deliver some of the effects seen with MSCs without transplanting cells, an approach often called cell-free. A 2017 review laid out the case and the open questions, which include how to standardize and dose these products. Our secretome page goes further.

Muse cells, short for multilineage-differentiating stress-enduring cells, were described by a Japanese research group in 2010. They are a small subpopulation within mesenchymal cell populations that can survive stress and form cells from all three embryonic germ layers in laboratory conditions. Clinical research is at an early stage, mostly in Japan. See our Muse cells page.

Cells and vesicles can come from your own body, such as fat or bone marrow, or from donor tissue such as umbilical cord. Each source behaves differently, and how a product is collected, processed, stored and tested changes what is actually in the vial. Two products sold under the same name can differ widely. That is one reason research results from one product do not automatically apply to another.

The FDA regulates most stem cell and exosome products as biological drugs, which means they need FDA approval before they can be marketed to treat disease. The agency's consumer guidance encourages patients to ask whether a product is FDA approved or being studied under an FDA investigational application, and to be wary of clinics that promise cures.

We think that guidance is sound. A good regenerative consult should leave you clearer on what is known, what is not and what you are being offered.

The FDA suggests patients ask specific questions before receiving any cell or exosome product. A shortlist:

• Is this product FDA approved for my condition, or being studied under an FDA investigational new drug application?
• Where do the cells or vesicles come from, and how are they processed and tested?
• What published evidence supports this specific use?
• What are the known risks, and who handles follow-up if something goes wrong?
• What is the full cost, including any repeat procedures?

If a clinic is vague on any of these, treat that as useful information. Side effects from any medical product can be reported to the FDA through its MedWatch program.

A regenerative conversation at LYV starts with a provider consult. Your provider reviews your history, labs and goals, explains the research in plain terms and gives you a straight recommendation, including when the answer is no. You can also read about stem cell harvest and storage or browse the regenerative overview.