Readers of this book will want to know whether melatonin supplementation is safe and effective. The book tends to the positive, but takes a cautionary approach. It admits that little is known for sure about safety, potential for tolerance or addiction, proper dosage. “At this point the continuous use of melatonin . . . is a gamble.” There is a whole chapter of cautions, reasons not to take melatonin, so the book is honest.

There is one red flag I have not seen elsewhere: melatonin is not the only substance produced by the pineal gland. What role do the other substances play? Could taking melatonin in isolation cause imbalances? This is a powerful hormone, to be used with care. Yet it seems to have great potential as a substitution therapy. And it is non-toxic—not lethal to mice at any dose.

As this book was released in 1996, it needs updating, but is comprehensive and informative as far as it goes. It is readable, concise, and seems to be well researched, with many source citations. ( )