Barrett was the consulting editor for the Consumer Health Library at Prometheus Books, and has been a peer-review panelist for two medical journals. He has also served on the editorial board of Medscape and the "Scientific Review of Alternative Medicine". According to his website, he "has written more than 2,000 articles and delivered more than 300 talks at colleges, universities, medical schools, and professional meetings. His media appearances include "Dateline", "Today", "Good Morning America", "Primetime", "Donahue", CNN, National Public Radio, and more than 200 other radio and television talk show interviews."