By Dr. Allison Smith, ZRT Laboratory Sex Hormone Binding Globulin (SHBG) is one of the most overlooked variables in hormone health. It directly controls how much testosterone is biologically active in your body — yet it rarely appears on standard blood panels. Whether you're dealing with symptoms of low testosterone, androgen excess, or unexplained hormonal imbalance, understanding SHBG is essential to getting the full picture. What is SHBG? SHBG is a protein produced primarily in the liver that binds tightly to testosterone — and to a lesser degree, oestradiol (E2) and dihydrotestosterone (DHT) — and carries them through the bloodstream....
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.
Many women going through menopause notice changes in their ability to remember things — and this is not just in their heads. A small, seahorse-shaped structure in the brain called the hippocampus is highly dependent on estrogen for synaptic plasticity, memory formation and neuroprotection. In this article, Margaret Groves of ZRT Laboratory explains the science behind menopause-related memory changes, why estrogen receptor expression declines with age, and why the “window of opportunity” for hormone replacement is critical to preserving cognitive function.
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.
Your adrenal glands are your body's frontline stress managers — producing cortisol, DHEA and adrenaline to keep you functioning under pressure. But when stress becomes chronic, these glands can fall out of balance, leading to fatigue, weight gain, insomnia, anxiety and more. Discover how adrenal hormones work, what imbalance looks like, and 10 evidence-based tips to restore balance.