By Robert Sawyer. A brilliant scientist tries to decode an alien message and a wealthy benefactor pays for her to undergo an experimental rejuvenation procedure, and her husband. It works for him, but not for her.

By Kathy Bell. In this first novel of the Infinion trilogy, the past, present, and future seem to meet and Adya Jordan, a forty year old mother, finds herself a teenager again.

By Terry England. Seventeen humans enter an alien vessel and return as nine-year-old children—and the world doesn’t know what to make of this “gift.”

By Dan Simmons. Temporal disruption comes up quite frequently. Specifically, the character of Rachel Weintraub experiences aging backwards.

By Margaret Peterson Haddix. Two old women are offered the chance to be young again. The experiment works, but it could be deadly.

By Philip K. Dick. The entire world begins to move backward—including the dead. The book tackles some big questions, both theological and philosophical.

By Arkady Strugatsky and Boris Strugatsky Vampire Fiction often falls into the Urban Fantasy sub-genre, and this series is a great example of how popular it has become.

By Roald Dahl. Not strictly a science fiction story, but they do end up in space. Charlie’s grandparents take pills that take twenty years off their lives—but Grandma takes too many.

By Fritz Leiber, Jr. This collection of short series includes one called “The Man Who Never Grew Young” and time runs backwards in this universe, but one man does not.

By F. Scotth Fitzgerald. This is perhaps the most recognizable example of the Age Regression sub-genre, though it is more of a Fantasy. A boy is born old, and ages backwards. It is a classic story and it’s nearly impossible to talk about Age Regression without mentioning this book.