Compounds & interventions

Testosterone

Longevity & Aging · covered by 16 outlets this week · tracked since 2026-10-27

Press: 11 mainstream 64 specialist 35 independent outlet-days

What it is

Evidence 8/10 · established for some uses Uneven · 2–8 by use Signals · regulator warning

Testosterone is the main male sex hormone, also present in women, that drives muscle, bone, libido and red blood cells. It is in the news because of a boom in ‘low T’ clinics, online prescribing and forum protocols, alongside research on how fatherhood, stress and ageing move levels. Replacement therapy is well established for men with diagnosed hypogonadism; for age-related decline the benefits are modest and the long-term trade-offs still being measured. Use for muscle or performance without a deficiency is doping, with documented harms.

The score describes testosterone replacement for men with confirmed hypogonadism. Treatment of normal age-related decline, use in women for libido and non-medical use for muscle are far less settled.

Evidence by use or claim · 1 preclinical to 10 thoroughly established

  1. Replacement in diagnosed hypogonadism8/10 · established for some uses

    approved, large safety trial

  2. Age-related decline in otherwise healthy men4/10 · early human evidence

    modest effects on sexual function, little on vitality

  3. Low libido in postmenopausal women4/10 · early human evidence

    short trials, no approved product in most countries

  4. Muscle and performance in healthy people2/10 · preclinical

    effective but non-medical use with known harms

  • RegulatorIn 2015 the FDA restricted approved use to men with hypogonadism from specific medical conditions and required labels to warn of a possible increase in heart attack and stroke risk. source
  • TrialThe TRAVERSE trial (NEJM, 2023) in 5,246 men with hypogonadism found no excess of major cardiovascular events, but more atrial fibrillation, acute kidney injury and pulmonary embolism in the testosterone group. source
  • TrialTestosterone raises red blood cell counts; polycythaemia is the most common reason to stop therapy in trials.
  • MarketWidely prescribed off-label through telehealth and ‘low T’ clinics, and sold on the grey market for bodybuilding, often in doses far above replacement.

Written by the Alivewire editors from the coverage below, 1d ago; rated 1d ago. Not medical advice; how the ratings work.

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