CiRA　Reporter

The terms “exosome” and “stem cell culture supernatant” are becoming increasingly common. These substances are marketed as anti-aging products in drugstores and on social media, where they are advertised as regenerative medicine claiming to prevent or treat diseases.

Exosomes are tiny vesicles used by cells to facilitate cell-to-cell communication, while stem cell culture supernatant is the liquid left after culturing stem cells. As exosomes are present in stem cell culture supernatant, they are often conflated in public discourse.

Many countries are researching exosome-based therapies and diagnostic methods that, in turn, are generating significant attention and high expectations. However, the safety and effectiveness of such treatments have not been scientifically validated. Notably, cases of improperly managed exosome treatments have been reported to cause severe harm to patients.

Consequently, Europe and North America have implemented regulatory measures requiring government review and approval for the medical use of exosomes. Despite these measures, many medical institutions continue to offer expensive, unproven exosome therapies, thus raising serious concerns.

In contrast, regulatory loopholes in Japan allow exosome treatments without oversight. Under current regulations, companies can only sell exosomes for experimental purposes and are prohibited from advertising their therapeutic effects. However, doctors are not prohibited from using exosomes in treatments, nor are they required to seek regulatory approval. Furthermore, while cell-based treatments fall under the Act on the Safety of Regenerative Medicine, exosomes are not subject to such regulations because they are not cells.

As a result, Japan has over 600 medical institutions offering exosome or stem cell culture supernatant treatments, far more than in Europe and North America.

Since exosomes are not cells, they are not legally considered regenerative medicine. Some treatments claim to use iPS cell-derived exosomes, but in many cases, these are simply stem cell culture supernatants from iPS cell cultures, not actual iPS cells. The scientific evidence supporting these products is still lacking, as with other exosome-based treatments.

While further research may eventually lead to safe and effective therapies, maintaining a critical stance against inflated claims and implementing clear regulations to protect patients is crucial.

>Reference: The need for regulatory measures regarding exosome therapy（October 25, 2024）