Testosterone is the most oversold and most misunderstood hormone in consumer health. It genuinely helps some people with specific, diagnosable conditions. It is also marketed aggressively to people whose evidence base does not support it. This hub separates those two things.
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Testosterone therapy in men
What hypogonadism actually is, what the Testosterone Trials and TRAVERSE found, and the risks around fertility, red blood cells, and the prostate.
Testosterone therapy in women
Why no FDA-approved product exists, the one indication international consensus supports, and why no lab value defines deficiency in women.
What it costs
Real price ranges for testing and treatment, what insurance typically covers, and how access differs by state.
How testosterone is measured
Total versus free testosterone, the role of SHBG, why morning timing matters, and where standard assays fall short.
What testosterone does
Testosterone is an androgen produced mainly in the testes in men and in the ovaries and adrenal glands in women. It contributes to sexual desire and function, muscle protein synthesis, bone mineral density, red blood cell production, and body fat distribution. It is present and biologically necessary in both sexes, at concentrations roughly ten to twenty times higher in men.
Levels decline gradually with age in both sexes. In men this is typically about one percent per year after the thirties, which is slow enough that most men never develop symptoms attributable to it. In women the decline is gradual and, importantly, is not driven by menopause itself the way estrogen loss is.
The recurring problem: symptoms are non-specific
Fatigue, low libido, poor concentration, weight gain, low mood, and disturbed sleep are the symptoms most often attributed to low testosterone. They are also the symptoms of sleep apnea, depression, thyroid disease, anemia, iron deficiency, chronic stress, medication side effects, and simply not sleeping enough.
This overlap is what makes the field so easy to market into. A symptom checklist that asks whether you are tired and less interested in sex will identify a very large fraction of adults, most of whom do not have a testosterone problem. Guidelines exist precisely to prevent that checklist from becoming a diagnosis.
Where the evidence is strong, and where it is not
| Claim | What the evidence supports |
|---|---|
| Improves sexual function in men with diagnosed hypogonadism | Well supported by randomized trials3 |
| Improves sexual desire in postmenopausal women with HSDD | Supported by meta-analysis and international consensus24 |
| Does not meaningfully increase major cardiac events in men with hypogonadism | Supported by a large dedicated safety trial5 |
| Improves energy and vitality | Not supported. The trial designed to test this found no significant benefit3 |
| Improves mood, cognition, or bone density in women | Not supported by current evidence4 |
| Appropriate for age-related decline without diagnosed hypogonadism | Recommended against by guideline1 |
Testing, in one paragraph
Testosterone should be measured on a fasting morning blood draw, and confirmed on a second separate morning before any diagnosis is made, because levels follow a daily rhythm and vary substantially day to day.1 When SHBG is likely abnormal, free testosterone measured by an accurate method is more informative than total. In women, standard assays are poorly calibrated to the low concentrations involved, and no cut-off defines deficiency.4
Questions worth asking before you start anything
- Have I been tested twice, on separate mornings, fasting?
- Have reversible causes been ruled out: sleep apnea, thyroid, anemia, medications, significant weight change?
- What exactly is the diagnosis, and does it match a guideline definition?
- What is the monitoring plan, and what would make us stop?
- For men: has fertility been discussed? For women: how is a female-appropriate dose achieved and verified?
The bottom line
Properly diagnosed hypogonadism in men and HSDD in postmenopausal women are real conditions with real, evidence-supported treatment. Being tired in your forties is not, by itself, either of them. The most useful thing this hub can tell you is where that line sits, because almost nobody selling testosterone has an incentive to draw it clearly.