Testosterone Replacement (Clinical)
For documented deficiency with symptoms. Not a casual optimization tool.
Approved Verified 27 August 2026
What it does
Among the most consequential interventions when properly indicated, and one of the most misused when it is not. The indication is symptoms plus documented deficiency — not a number alone.
Exogenous testosterone restores serum levels in hypogonadal men, with downstream effects on muscle protein synthesis, erythropoiesis, mood, and sexual function.
What the evidence shows
Overall evidence strength: Moderate certainty
Who it's for, who should skip
Documented deficiency plus symptoms (low libido, fatigue, reduced muscle mass, depression) — not normal-range testosterone treated as a number to optimize. Casual optimization shifts the risk-benefit considerably: cardiovascular, fertility, dependency.
Skip it if
- trying to conceive — TRT suppresses fertility — avoid while trying to conceive.
- normal-range testosterone without documented deficiency — Testosterone within the normal range correlates poorly with symptoms; a number alone is not an indication.
Running it
- Dose
- per physician protocol
- Titration
- injectable or transdermal; indication is symptoms + documented deficiency (typically total testosterone <300 ng/dL)
Measuring it
Retest Total testosterone — Total testosterone and hematocrit 3–6 months after starting, then yearly once stable — free testosterone only when SHBG is off. PSA per age-based screening guidance; settle fertility plans before starting..
- Total testosterone
- Total testosterone
- Estradiol
- SHBG
Safety
- polycythemia (elevated hematocrit)
- suppressed fertility (often reversible, sometimes not)
- accelerated benign prostatic hyperplasia, breast tenderness
Stacking & alternatives
Access & cost
Prescription or clinician order — typically via endocrinology or urology (Schedule III controlled substance).
Last reviewed 27 August 2026. Regulatory status verified 27 August 2026.