All the details one could ask for when it comes to steroids. The book goes briefly over the physiology of hypertrophy (increase in muscle size), the chemical and biological properties of testosterone and its main derivatives, and simple therapy cycles. Then the author dives into what seems like every known steroidal and non-steroidal compound associated with bodybuilding. There's the chemical interaction, user study references, history of development, enumeration of possible side-effects with statistics when available, and so on for every single one of them.
At about a 1000 page, this is probably not meant to be read cover to cover, but I was engaged enough to push through, albeit with some skimming of repetitive portions (like oral steroids are hepatotoxic and you don't need to read that a 100 times). This clarified the very confusing and almost feared subject of steroids for me to a good extent. If you are curious about steroids, and want to actually learn how they work without the extreme stigma that comes attached with the topic, I can highly recommend this book!