Men's health
Sleep and hormone levels: what controlled research shows
Many things can influence hormone levels. Before looking for less common explanations, it's often useful to consider everyday factors that research has tested in controlled settings. One of them is sleep.
5 min read
A controlled laboratory study
In a 2011 research letter in JAMA, Leproult and Van Cauter looked at what happens to testosterone when healthy young men sleep less for a week.
Ten healthy young men (average age about 24) with no hormone, psychiatric or sleep problems took part. After nights of longer sleep, they were limited to five hours of sleep a night for eight nights in a sleep laboratory. Blood samples were taken frequently over 24-hour periods.
After the week of short sleep, their daytime testosterone levels were 10–15% lower than when they were well rested. The difference was most noticeable in the afternoon and evening.
The researchers noted that this drop is similar in size to the change sometimes seen with ageing over a number of years, even though these men were young and healthy. Nothing else changed: no illness, no ageing, only less time to sleep.
The authors also pointed out that much of a man's daily testosterone release happens during sleep, and that broken sleep and conditions such as obstructive sleep apnoea have been linked with lower testosterone in other research.
The wider evidence, and its limits
A 2021 review that pooled 18 studies (252 men) found that going without sleep entirely for 24 hours or more was linked with a clear drop in testosterone. Cutting sleep by a few hours a night for several nights did not show a statistically significant overall effect when the studies were combined.
Results vary with how a study is run: how much sleep is lost, when, and whether blood is measured only in the morning or across the whole day. Laboratory studies that measure across 24 hours, or in the afternoon and evening, more often show a drop.
Obstructive sleep apnoea has also been linked with lower testosterone in observational research, in some studies even after accounting for age and weight, and more strongly in more severe cases.
Everyone is different. How much sleep people need varies, and many other things also affect hormone levels, including weight, physical activity, stress, health conditions, medicines and natural ageing. No single study, or even a review of many studies, can tell you what is happening in your own body.
The practical takeaway
The researchers behind the 2011 study suggested it's reasonable to think about recent sleep when looking at hormone-related symptoms. Sleep that is regularly shorter than you need is common, and for many people it can be changed.
If you're worried about your sleep or how you're feeling, the right next step is to talk to a registered practitioner. They can take a full history, arrange tests if they're needed, and look at the whole picture, including sleep habits, possible sleep disorders and other factors.
This article is general information only. It isn't personal medical advice and doesn't recommend for or against any treatment or test. Talk to a registered practitioner about your own health.
References
- Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011;305(21):2173-2174. doi:10.1001/jama.2011.710
- Su L, et al. Effect of partial and total sleep deprivation on serum testosterone in healthy males: a systematic review and meta-analysis. Sleep Med. 2021;88:267-273.
- Related reviews examining sleep duration, obstructive sleep apnoea and hormone profiles (including work published in Reviews in Endocrine and Metabolic Disorders and Andrology).
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