Hormone Health Hub: Expert Insights on Testing, Balance & Better Living — diurnal cortisol testing

A family’s decision to become a “running family” transformed their two sons’ ADHD outcomes — no stimulants, no antidepressants, just daily exercise. Dr. Allison Smith explains the neuroscience behind why this works: from brain wave patterns and low sympathetic tone to dysfunctional cortisol rhythms and neurotransmitter imbalances. A compelling read for any parent or clinician looking beyond medication.

Explore the powerful connection between cortisol, melatonin, inflammation and circadian rhythms. Learn how disrupted hormone patterns may contribute to fatigue, insomnia, stress, cardiovascular disease, diabetes, depression and even cancer risk. This article reviews the latest insights from ZRT Laboratory doctors on hormone testing, sleep biology, stress physiology and the importance of maintaining healthy daily hormone rhythms for long-term wellness.

When it comes to topical testosterone therapy, more is not always better. Dr. Allison Smith of ZRT Laboratory explains the U-shaped curve phenomenon — where both too little and too much testosterone produce the same symptoms — and why starting at low doses and titrating carefully is essential. She also outlines the key markers to check when a man’s testosterone numbers look good on paper but his symptoms persist.

An estimated 80% of adults will experience some level of adrenal fatigue in their lifetime — yet it remains one of the most under-diagnosed conditions in modern medicine. When the adrenal glands are chronically overtaxed, cortisol output drops, leaving the body unable to manage stress, stabilise blood sugar or mount immune defences. This article explores the symptoms, causes and what you can do to identify and address adrenal fatigue through targeted hormone testing.

Cortisol can be measured in saliva, blood and urine — but each method tells a different story. Saliva reflects bioavailable cortisol, blood measures total output, and dried urine captures the full circadian pattern. This article explains the clinical differences and helps you choose the right test.