Testosterone Measurement Best Practices
The speaker outlines critical best practices for accurately measuring testosterone. He stresses that total testosterone reflects overall production, while free testosterone (typically 2-3% of total) is the biologically active form. Both are important. Measurements should ideally be taken early in the morning due to testosterone's pulsatile, diurnal rhythm, where levels are highest. Patients should be fasted and well-hydrated, and avoid biotin supplements, which can cross-react with assays and lead to inaccurate results. Crucially, he advises against making any treatment decisions based on a single reading, as levels can vary significantly. Repeat measurements, combined with a thorough assessment of symptoms, are essential to confirm low levels and determine the appropriate path forward, whether natural interventions or hormone therapy.
Testosterone is secreted in a pulsatile manner with a diurnal rhythm, peaking in the morning. SHBG (Sex Hormone Binding Globulin) and albumin bind most testosterone, rendering it inactive until dissociated. Free testosterone is unbound and readily available to target tissues. Biotin can interfere with immunoassay tests, leading to false readings. Hydration status affects hematocrit, which can influence perceived blood values.
So typically the best way to assess peak levels would be early in the morning and ideally you would have um not taken certain confounding variable supplements like biotin that can cross detect is you know estrogens and whatnot.

