Short sleep can lower testosterone, but by how much, and does it last? Here's what the sleep restriction research found and which fixes are worth your effort.
In a 2011 JAMA study, 10 healthy young men who slept under five hours a night for a week saw daytime testosterone drop by about 10 to 15%. Sleep apnea is also linked to low testosterone, though much of that connection runs through excess weight. Seven or more hours of steady sleep, weight management and treating sleep disorders matter far more than any supplement.
Testosterone and sleep are closely linked. Much of a man's daily testosterone release is tied to sleep, so when sleep gets cut short, levels can drop. The best-known experiment found that one week of sleeping under five hours a night lowered daytime testosterone by about 10 to 15% in healthy young men.
That's a real effect, but it's worth keeping in proportion. It was a small study, the drop was moderate, and levels stayed in the normal range. The bigger lesson is that chronic short sleep, sleep apnea and the weight gain that often travels with both can drag testosterone down, and fixing those does more than any supplement.
The study most people cite was run by Rachel Leproult and Eve Van Cauter at the University of Chicago and published in JAMA in 2011. Ten healthy, lean men with an average age of about 24 spent three nights in a sleep lab with up to 10 hours in bed, then eight nights with only five hours in bed.
According to the University of Chicago's summary of the study, testosterone normally falls about 1 to 2% a year with age, so the drop was comparable to aging 10 to 15 years. That comparison is eye-catching, but it describes a short-term dip after a week, not a permanent change.
The authors themselves called for more research, including whether sleep should be part of how doctors evaluate low testosterone.
A 2014 review by Gary Wittert in Current Opinion in Endocrinology, Diabetes and Obesity concluded that the daily rise and fall of testosterone appears to depend on sleep itself, rather than just the body clock. Total sleep deprivation lowers testosterone. Partial sleep restriction appears to matter mainly when it cuts into the first part of the night, according to the review.
In practice, that means both how long you sleep and how continuous that sleep is can matter. Going to bed very late, waking repeatedly, or having breathing interruptions all break up the sleep that testosterone production relies on.
The relationship runs both ways. Low testosterone itself is linked to fatigue and low mood, and those can make sleep worse. If you're tired all the time, it's worth looking at both sides with a doctor rather than assuming one causes the other. Our guide to the symptoms of low testosterone in men explains how proper testing works.
Obstructive sleep apnea (OSA), where the airway repeatedly collapses during sleep, is common in men with low testosterone. But the link is more complicated than it first looks.
A 2019 meta-analysis in Frontiers in Endocrinology (Cignarelli and colleagues) pooled 12 studies with 388 men with OSA. Treatment with CPAP, the standard breathing machine, did not significantly change total testosterone, free testosterone or the hormones that control testosterone production. That held whether men started with low or normal levels, though men with low testosterone showed a non-significant trend toward improvement.
Both that meta-analysis and the Wittert review point to obesity as a major driver. The association between sleep-disordered breathing and testosterone weakens or disappears once body weight or waist size is taken into account. Wittert notes that weight loss tends to raise testosterone, while CPAP results are inconsistent.
None of this means sleep apnea doesn't matter. It wrecks sleep quality and has health consequences of its own, so loud snoring, gasping at night or heavy daytime sleepiness are good reasons to see a doctor, who can arrange a sleep study. Just don't expect a CPAP machine alone to fix low testosterone.
Testosterone therapy and sleep apnea interact too. Mayo Clinic lists worsening sleep apnea as a possible risk of testosterone therapy, which is one reason doctors ask about snoring and sleep before prescribing it. Wittert's review suggests the effect is usually temporary, but it's still something to raise with your doctor.
The CDC recommends 7 or more hours of sleep a night for adults 18 to 60, 7 to 9 hours for ages 61 to 64, and 7 to 8 hours from 65 on. Its practical tips line up with what the testosterone research points to:
No supplement can make up for chronic short sleep. Some people use magnesium as part of a wind-down routine, and our magnesium supplement guide covers forms, doses and what the evidence does and doesn't show. Zinc matters for testosterone mainly if you're actually low in it, which our article on how zinc and testosterone are connected explains.
Ashwagandha is another popular choice for stress and sleep. If you're considering it, timing questions are covered in our guide to the best time to take ashwagandha. Talk to your doctor before starting any sleep supplement if you take sedatives, antidepressants, thyroid medicine or blood pressure medicine, or if you have a diagnosed sleep disorder.
Cutting sleep to under five hours a night for a week lowered daytime testosterone by about 10 to 15% in a small study of young men. Sleep apnea is also tied to low testosterone, though much of that link runs through excess weight, and CPAP alone doesn't seem to raise levels. Getting seven or more hours of steady sleep, managing weight and getting snoring checked are the changes that matter. Supplements are a distant second.