I liked the topics and historical context about the drugs described but didn’t love the execution. There was a lot of memoir-type style mixed-in and I don’t mind that but it got very lengthy and opinionated. I wish there was more of a connected thread/theme/message throughout as it was really 3 separate small books compiled together which felt disjointed. 
Did not like his tone towards indigenous people in the last section.  Ultimately while I am not disappointed I read this book, it could have been better. Parts of it were engaging and had good research but I did not learn much new information and wish the author had a more cohesive point of view instead of compiled ramblings. 
I have heard his first book about psychedelics is better and so I might read that, but I would not recommend this book to a friend.