Safety and efficacy claims made by US businesses marketing purported stem cell treatments and exosome therapies.

Examining websites of US businesses engaged in direct-to-consumer advertising of putative stem cell treatments and exosome therapies, this study investigated the marketing claims such companies make about the purported safety and efficacy of these products. Data mining and content analysis of company websites were used to identify and analyze safety and efficacy claims. Of the 978 businesses analyzed, less than half the companies made identifiable claims about the safety and efficacy of their advertised stem cell and exosome products. We also explored how companies framed the stem cell and exosome products they promoted. Representations ranged from assertions that such products are unproven and investigational to claims they constituted cures. Most advertising frames fell between these poles. Some businesses include in their marketing representations claims about the safety and efficacy of advertised products. Businesses that did not make such assertions use other techniques to attract prospective clients.