According to recent study conducted by UC Davis and published in journal Cell Stem Cell, advertising and proposing stem cell therapy to patients conflicts with the existing federal law, since most states clinics do not have the requisite approval to conduct this treatment. In fact, there are quite a few therapies that do not even have proper scientific evidence that these treatments work, in the first place.

Clinics that offer stem cell therapies for treatment are spread all across the country and most of them are located in California, New York, Arizona, Texas and Colorado. There are as many as 570 clinics that are found in almost every state of the country. These therapies are being offered by clinics as treatment for several medical conditions that could be anything between mild bone injury to something as serious as a brain disease.

The study also points out that the therapies offered by these clinics may sometimes be effective but science does not support them and consider some as "outlandish," as they are not backed by research.

According to MIT Technology Review, the US FDA have regulations that restricts the use of cell-based therapies. The most common type of illegal therapy offered by these clinics is non-homologous stem cell therapy where the doctors extract cells from one tissue and then transfer it to an irrelevant body part. While there is no evidence that this procedure is dangerous, there is no research proving their safety and effectiveness either.

Leigh Turner, study co-author and bioethicist, recommends people to be careful of clinics that offer stem cell therapies. Not only are these clinics giving false hopes to its patients, they can also seriously affect the patients if the procedures go wrong. For now, there is not enough research to support safety and efficacy of stem cell therapy.