Testosterone production in men is heavily sleep-dependent. The largest pulse of testosterone release occurs in the early hours of sleep, during slow-wave phases. Research published in JAMA found that one week of sleep restricted to five hours per night reduced daytime testosterone levels by 10 to 15 percent in young healthy men. In men over 50 who already have declining production, the effect of poor sleep is proportionally more damaging.
The Downstream Effects of Low Testosterone From Poor Sleep
- Reduced muscle protein synthesis and accelerated muscle loss
- Increased fat storage, particularly around the abdomen
- Reduced libido and sexual function
- Lower mood, motivation, and cognitive performance
- Increased cardiovascular risk through unfavourable changes to lipid profiles
What Women Should Know
Testosterone is not exclusively a male hormone. Women produce it in the adrenal glands and ovaries, and it plays a significant role in muscle maintenance, libido, bone density, and energy levels. The same sleep-dependent mechanisms that suppress testosterone in men apply in women. Poor sleep disrupts the hypothalamic-pituitary-gonadal axis regardless of sex.
The Priority Order
If a middle-aged man presents with low testosterone, sleep duration and quality are among the first clinical considerations. Before any hormonal intervention, addressing sleep is both appropriate and effective. In many cases, restoring sleep quality alone produces meaningful improvements in testosterone, energy, body composition, and mood within four to six weeks.