Understanding total testosterone vs free testosterone Testosterone Test: Free & SHBG, High vs Low vs. Normal Levels The production of this sex hormone is controlled by the secretion of many other hormones. The key difference between these two kinds of testosterone is how they exist in the bloodstream. You need to have them in healthy concentrations so that your body can perform all functions normally. Testosterone, often shrouded in myths and misconceptions, is a hormone that has been the subject of much debate and misunderstanding. Dispelling these myths is essential for a better understanding of testosterone and its role in health and wellness. This section aims to clarify some of the most common misconceptions about testosterone, providing evidence-based insights into this vital hormone. Research-backed tools, tactics, and techniques to maximize your health, delivered to your inbox every Monday. Dr. James R. Staheli is the Medical Director for Broad Health, Hone Health’s affiliated medical practice and a family medicine doctor in Atlanta, Georgia. Low testosterone, also known as hypogonadism, can manifest in various ways. Symptoms may include decreased energy levels, reduced muscle mass, diminished libido, erectile dysfunction, mood swings, and feelings of depression. As we navigate through life, several factors come into play that can influence testosterone levels, shaping our overall hormonal balance. Free testosterone, on the other hand, refers only to testosterone that is not bound to proteins. As the “active” form of the hormone, free testosterone can readily bind to receptors and exert its effects on the body. Generally, free testosterone makes up about 2% to 3% of total testosterone. Ahead, men’s health experts answer the question, and share tips for supporting your T levels at any age. Total testosterone is a total measure of testosterone in the bloodstream — both free and bound. In dispelling common myths and misconceptions about testosterone, we aimed to provide clarity and information, fostering a better understanding of this hormone’s role in our bodies. The FDA currently advises against treating men with low testosterone caused only by aging. The blood sample is analyzed in a laboratory, and the results show the concentration of free testosterone in the bloodstream. It is important to note that total testosterone levels are also measured in addition to free testosterone levels. Total testosterone includes both the free testosterone and testosterone that is bound to other proteins in the body. Moreover, we addressed the significant impact of lifestyle choices on testosterone levels. % Free Testosterone is a vital biomarker used to evaluate hormonal health, particularly in men, but also in women. This “free” testosterone is biologically active, meaning it is available to interact with cells and exert effects on the body, such as influencing muscle growth, fat distribution, mood, and sexual function. The study found that testosterone levels naturally decline with age, with an average decrease of approximately 1-2% per year. In older adulthood, expected testosterone levels generally range from 200 to 900 ng/dL. This age-related decline in testosterone can have various effects on individuals, including changes in muscle mass, bone density, and