Peter Jaret is the author of several health-related books, including "In Self-Defense: The Human Immune System" (Harcourt Brace), "Nurse: A World of Care" (Emory University Press), and "Impact: On the Frontlines of Public Health" (National Geographic). A frequent contributor to National Geographic, The New York Times, Reader’s Digest, Health, More, AARP Bulletin, and dozens of other periodicals, Jaret is the recipient of an American Medical Association award for journalism and two James Beard awards. He lives in Petaluma, Calif.
Sales of prescription testosterone pills, gels, and patches have soared. But are they necessary? And do they work? Here’s the latest evidence.