But it's also not how CRISPR/CAS9 works either. Gene therapies usually involve a process of extracting stem cells, modifying a small number of them in vitro, growing them, and then either using them to grow tissues out of the body for later implantation, or injecting them into targeted tissues.
It's not an injection you take that goes out and edits every cell and you magically change shape. It makes for good scifi, not so much good science.
