Made overnight. Destroyed by short sleep.
Testosterone peaks in the last REM cycles. Cut sleep, cut T.
5 hours/night for 1 week = 10–15% drop in daytime testosterone.
That's the hormonal aging of a decade — in seven nights.
Luteinizing hormone spikes during slow-wave sleep and triggers T release.
Untreated sleep apnea can cut testosterone by up to 40%.
Poor sleep raises cortisol — and cortisol suppresses T at the source.
Evidence, checklist and FAQ on our blog.