Book excerpt: Progestogens are a class of steroid hormones that bind to and activate the progesterone receptor. This book is a guide to the use of progestogens for clinicians. Beginning with an overview of structure, biochemistry and classification, the following chapters discuss methods of administration, pharmacokinetics, metabolism and the physiological actions of progesterone. The remaining sections of the book cover clinical usage guidelines for progestogens, their role in contraception, side effects and contraindications. The book concludes with a chapter offering guidance on prescription writing and detailed references. Key points Guide to progestogens for obstetricians and gynaecologists Provides step by step detail on structure, classification, and pharmacokinetics Includes clinical usage guidelines, side effects and contraindications Features chapter on prescription writing