Androgens and Testosterone
Testosterone is known for being affected by poor sleep (on a related note, you tend to sleep worse as you age, and this exacerbates sleep deprivation problems)6,7. Studies have shown that getting three fewer hours of sleep for five days reduced testosterone by over 10%8, whereas another study showed a 30.4%9 decrease! These reductions all happened within 24 hours of sleep deprivation10,11. Similar to insulin, getting enough rest quickly reverses this decline.
Sleep deprivation is associated with reduced testosterone. Akin to insulin, it normalizes once you get enough rest.