Since 1996 Dr Thomas Guilliams has spent his time studying the mechanisms and actions of natural-based therapies, and is an expert in the therapeutic uses of nutritional supplements. He has invested much of his time studying epidemiological data and clinical research to help him develop evidence-based nutritional solutions that enhance the efficacy of nutritional therapies in clinical practice. Dr Guilliams teaches at the University Of Wisconsin School Of Pharmacy, where he holds an appointment as a Clinical Instructor; and at the University Of Minnesota School Of Pharmacy and is a faculty member of the Fellowship in Anti-aging Regenerative and Functional Medicine (A4M). Thomas has spent years looking into the mechanisms of stress and the hypothalamic pituitary adrenal axis (HPA) dysfunction and is the author of several books on the topic of chronic disease prevention. More recently he has authored a useful reference book outlining the effects of stress and the HPA axis, focusing on clinically relevant advances in the understanding of the stress response system.