Steroid hormones secreted from peripheral reproductive endocrine tissues regulate many important physiological functions not only during development, but also into adulthood and play a key role in the growth, differentiation and function of reproductive tissues. In this book, the authors present current research in the study of the biosynthesis, functions and health implications of steroids. Topics include cytotoxic steroids and derivatives in the development of anticancer drugs; identifying steroid hormones in biological and environmental samples; steroid receptors involvement in the pathogenesis of abnormal ovarian follicular cysts; oestrogen treatment after menopause to protect against dementia and cognitive decline; the evolving role of steroids in immunosuppression and transplantation; nasal steroids in adenoidal hypertrophy; and cytogenetic damage following anabolic steroids exposure.