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

Weight loss failure is rarely just about willpower or diet — hormones are almost always involved. In this Q&A, Dr. Alyssa Burns-Hill of ZRT Laboratory tackles the most common questions from people struggling to lose weight despite their best efforts: from thyroid interference by the contraceptive pill and stress-driven cortisol cravings, to estrogen-reducing supplements, natural progesterone for menopause, and why 5-HTP can be a game-changer for mood, sleep and comfort eating.

Cortisol is your body’s primary stress hormone, produced by the adrenal glands in response to physical, mental and emotional stress. While it plays a vital role in energy metabolism, immune function and cardiovascular health, both chronically high and chronically low cortisol levels can cause significant health problems — from fatigue, weight gain and sleep disorders to burnout and adrenal exhaustion. This article explains what cortisol is, what happens when it goes wrong, and why regular testing matters.

Reverse T3 (rT3) is one of the most misunderstood markers in thyroid testing. Often called the “hibernation hormone,” it is frequently claimed — without scientific basis — to block thyroid receptors and slow metabolism. In Part 2 of this series, Margaret Groves of ZRT Laboratory examines what the peer-reviewed literature actually says about rT3, when elevated levels are clinically meaningful, and how to interpret the T3/rT3 ratio in the context of a comprehensive thyroid assessment.

Most of us know when something feels off — fatigue, weight gain, mood swings, poor sleep. But fewer people realise that a hormonal imbalance is often at the root. Learn how the endocrine system works, what throws it out of balance, and how at-home hormone testing can help you find answers.

Infertility affects 1 in 8 couples worldwide — yet many are rushing into expensive IVF without first addressing the hormonal imbalances that may be silently undermining their chances. In this wide-ranging clinical discussion, Dr. Alison McAllister of ZRT Laboratory shares her expertise on the hormonal causes of infertility in both men and women, the key tests that are too often missed, and the complementary strategies that can dramatically improve outcomes.