An edited compendium of the best of Mark Crislip’s science-based medicine essays dealing with supplements, complementary and alternative medicine (SCAM). This book explains the harm—why SCAM is bad for people, animals, and the environment. It also explains why our powers of logic are often powerless against SCAM, including detailed analyses of statisical errors and fallacies. It then covers selected aspects of SCAM in detail: probiotics, herbs and supplements, chiropractic, homeopathy, acupuncture, and vaccine denial. Special emphasis is made on infectious complications caused by SCAM practices and practitioners. A final section on miscellaneous therapies exposes some unusual treatments, from moxbustion to cranialsacral therapy.