What do doctors say about Prevagen?

I'm curious, could you elaborate on what medical professionals have to say about Prevagen? Do they endorse it for its claimed cognitive benefits, or do they have reservations about its efficacy and potential side effects? What kind of evidence, if any, do doctors rely on when evaluating the safety and usefulness of this supplement? Additionally, have there been any studies or research that have shed light on Prevagen's effectiveness in improving memory or overall brain health?