"What are exosomes?" is the question we get most, from patients and from practitioners who have been asked by patients. Here is the answer we give.
The biology in three sentences
Exosomes are tiny membrane-bound vesicles, about 30 to 150 nanometres across, that cells release to carry proteins, lipids and RNA to other cells. They are one type of extracellular vesicle, defined by the way they form inside the cell before release. A receiving cell can take one in and change its behaviour in response to the cargo.
That is the whole mechanism. Everything else, from wound-healing research to serums, is an application of the idea that cells use these vesicles to send instructions, and that we can collect those vesicles and deliver them somewhere useful. Our reference page goes deeper into how they form and what is inside.
What "exosome therapy" means in a clinic
In practice, exosome therapy almost always means one of two things. The first is topical application immediately after a procedure that opens the skin barrier, such as microneedling, fractional laser or radiofrequency microneedling. The exosome preparation is applied to the treated area and, in some protocols, sent home with the patient for the following days. The second is scalp application after microneedling for hair and scalp concerns.
A third category, injecting or infusing exosomes, exists but is unapproved in the United States and has been the subject of FDA warnings. We do not supply products for that purpose and we advise clinics not to offer it.
Exosomes for skin: what is supported
The strongest human data is post-procedure. Several small controlled studies have found that applying mesenchymal-cell-derived exosomes after laser or microneedling reduced redness and downtime and improved measures of texture compared with the procedure alone. Cell-culture work shows that the same vesicles encourage fibroblasts to make collagen and dampen inflammatory signalling.
On intact skin, without a procedure, the picture is less clear. Vesicles of this size do not pass easily through an undamaged barrier, and studies that separate the effect of the exosomes from the rest of the formula are scarce. We tell clinics to position at-home use as a complement to in-clinic treatment, not a substitute.
Where the vesicles come from
The source cell decides the cargo. Products are made from human mesenchymal cells (umbilical cord, adipose, bone marrow), from platelets, from animal cells, or from plants such as rose or ginger. Human MSC-derived vesicles have the most research behind them for skin and wound applications. Plant vesicles are structurally similar but carry plant cargo and are less studied on human skin. Any product should name its source; ours are human umbilical-cord MSC-derived and we publish the donor screening and culture conditions with every certificate of analysis.
Questions a patient should ask
- What product is being used, who makes it, and can I see the certificate of analysis?
- Is it applied topically or injected? If injected, why, and under what authorisation?
- What does the procedure achieve without the exosome step, and what does the exosome step add?
- How has the product been stored between delivery and today?
- What side effects have you seen?
A clinic that answers these easily is a clinic that has thought about them. We would rather a patient ask and choose us than not ask at all.