Convert units
Convert total testosterone between ng/dL, nmol/L, and ng/mL.
Lab context
Total vs free testosterone: why one number is not the whole story.
Total testosterone is often the first number people look at, but lab interpretation can depend on symptoms, repeat morning testing, reference ranges, SHBG, free testosterone, medications, sleep, fertility goals, and other health context.
Total testosterone
Total testosterone measures testosterone in blood including hormone bound to proteins and unbound hormone. It is useful, but the number alone does not diagnose a person. Lab ranges and testing methods vary.
Free testosterone and SHBG
Free testosterone refers to the unbound portion. SHBG, or sex hormone-binding globulin, binds testosterone and can affect how much is available to tissues. Some guidelines discuss free testosterone in selected cases, such as borderline total levels or suspected SHBG-related interpretation issues.
Why context matters
- Symptoms are not specific to testosterone and can overlap with sleep, thyroid, mood, medication, metabolic, and lifestyle factors.
- Morning timing and repeat testing may matter in clinical evaluation.
- Fertility concerns can change the treatment conversation.
- Reference ranges vary by lab; screenshot archaeology is not medicine.
Useful tools
Blood test guide
Organize test timing, repeat-test questions, markers, and clinician discussion points.
Dosing risks
Understand why unsupervised testosterone or hidden steroid use can create real risks.