We rely on medications to treat a wide range of illnesses, from the common cold to serious conditions like cancer. Despite how frequently drugs are used in modern medicine, many people have little understanding of how they are developed or how they work in the body. Drugs Explained is an open-source book that takes the mystery out of medications. Learn how drugs are developed, how they work inside your body, and what all that fine print on medication labels really means. Finally understand the science behind your medicine cabinet!
I have 30 years of experience in the pharmaceutical industry and have contributed to the development of many drugs. Currently, I am Head of the Modeling and Simulation Group within Early Development and Translational Sciences at Astellas. I am a Fellow of the American Association of Pharmaceutical Sciences, American College of Clinical Pharmacology, and the International Society of Pharmacometrics. I am also Editor-in-Chief of The Journal of Pharmacokinetics and Pharmacodynamics and have published more than 80 papers in pharmacokinetics, clinical pharmacology, and drug development.
I have worked in the pharmaceutical industry most of my life, on numerous products that reached the market and many more that did not. Over the years, I have learned how drugs are developed. And while I may have learned the process, I have noticed that many people working at pharmaceutical companies do not know what we actually do. They may say we develop and make drugs. This is true, but it trivializes the process. What does it mean to develop a drug? What are the activities that are necessary to bring a drug to market? There are whole groups of individuals in companies who don’t know. These may include the administrative staff, the legal team, the contracts team, the chemists, and the list goes on. Even among scientists employed by a company, while they may be experts in their particular area, they may not be familiar with the entire drug development process.
Starting around 2013, I began developing a series of lectures at Astellas to explain the big picture of drug development, with an eye towards the drug label, so participants could better understand how to read it and comprehend the activities involved in creating it. This course was named – Drugs 101. This book is an extension of those lectures. Each chapter was a lecture in the course. Let me state up front, I know this book is decidedly US-centric in its approach. I barely mention laws other than the Federal Food, Drug, and Cosmetic Act or other regulatory agencies other than the FDA. This is the “write what you know philosophy.” Perhaps in the future, I can expand into other regions and understand how their laws and regulations affect drug development. For example, privacy laws are much stricter in the EU; what impact does this have on drug development?
I’ve had so much fun writing this book. I’ve written many books, and this one is a far departure from my usual fare. I’ve decided to take a more conversational tone to make it more reader-friendly. Drug development is fascinating and full of little tidbits of trivia and stories that are interesting (at least to me). I hope you find these little bits of trivia and history as interesting as I do.
I also wanted to try something different with this book: make it a living document available online. I plan to update it regularly, rather than releasing editions every few years. I also don’t plan to sell it to make money. I will, however, make it available on Amazon for those who want a hard copy. I learned a long time ago that if you want to make money, don’t write a science book. The only one making money on publishing is the publisher. But I don’t write these books to make money anyway. I write them because I have something to say, and it has to come out, much like why a musician writes music or an artist creates their art — not that I am comparing myself to a musician or an artist. Lol.
I’ve got lots of ideas for the future updates: new stories, reader-requested topics, and new chapters. I want to add a chapter on the sales and marketing of pharmaceuticals, but it will require significant time since I am not an expert in this area. Look for that in the future. I also want to write material on food regulation (Drugs and Food Explained?) and medical devices, perhaps even cosmetics.
I am trying to figure out the best way to disseminate the book. I will be making it available (eventually) on GitHub (https://github.com/peterbonate/Drugs-Explained) and Zenodo. I will also be working on a personal website at peterbonate.com. If there is something you want to see, don’t hesitate to write me at peter@peterbonate.com.
I want to thank all those who contributed to this book. Many researchers graciously allowed me to reprint their figures. What would I have done without Wikipedia and Wikimedia Creative Commons for many of the images in the book? Thank you.
I would also like to thank the many reviewers of the book who helped me make it more interesting and relevant. Thank you to my team: Souvik Bhattacharya, Mary Choules, Alexis Hoerter, Hu Huang, Jace Nielsen, Pouye Sedighian, Vijay Siripuram, Junko Toyoshima, and Jared Weddell. You were all a great help in making this more cohesive. I didn’t want to write the regulatory chapter, but I listened to your advice, and you were right; the book needed it. I want to thank Salaheldin Hamed for his review of that material. His comments made it a lot better overall. I also want to thank my friend, Christiane Collins, who never saw a contraction she liked. Thank you very much for reading this book and giving me your thoughts.
Peter Bonate, March 2026
2026
I am deeply grateful to the many colleagues and reviewers who generously gave their time to read drafts of this book prior to publication. Their thoughtful comments, critical insights, and careful attention to detail greatly strengthened the clarity, accuracy, and overall quality of the final manuscript. Any remaining errors or omissions are, of course, entirely my own.
If YOU see any errors, please reach out to me at peter@peterbonate.com