LANA ASPREY, M.D., is a Karolinska-trained physician who runs an international natural fertility consulting practice, helping couples recover fertility using techniques outlined in "The Better Baby Book." She is the former medical director of a lab testing company working with neurological immunity to environmental factors and practiced medicine in Stockholm, Sweden.

DAVE ASPREY, MBA, is a well-known blogger on health and human performance. As "the Bulletproof Executive," he's been featured on ABC's "Nightline" and CNN and in "Vogue" and "Men's Health." For nearly a decade, he's run the Silicon Valley Health Institute, an anti-aging nonprofit education group.