Editorial
Written byMen's Health Istanbul Editorial Team
Medical reviewer (awaiting sign-off)Prof. Dr. Bülent Alıcı
Published
Updated
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The short answer
The link between sleep and testosterone keeps coming up because testosterone is released largely during sleep and several studies suggest poor sleep can lower it. A small 2011 study found that one week of sleeping about five hours a night lowered daytime testosterone by 10 to 15% in young healthy men. A 2014 review linked sleep disorders such as obstructive sleep apnoea with lower testosterone, while noting that obesity complicates the picture. These are not new findings, and they do not show that better sleep treats low testosterone, but they make sleep worth checking.
Key takeaways
- The key studies are from 2011 and 2014; they are discussed again because the question matters, not because they are new.
- In a small 2011 study, a week of about five hours' sleep a night lowered daytime testosterone by 10 to 15% in young healthy men.
- Sleep apnoea and low testosterone often occur together, but obesity is a shared factor that makes cause and effect hard to separate.
- If you have symptoms of low testosterone, it makes sense to look at sleep as part of the assessment.
What happened?
Nothing new was published this month, and we want to be clear about that. The two pieces of research most often quoted on sleep and testosterone date from 2011 and 2014. They keep resurfacing in articles, podcasts and social media, which is why it is worth looking at what they actually showed.
The first is a small experiment by Leproult and Van Cauter, published in JAMA in 2011. Ten healthy young men spent a week in a laboratory restricted to about five hours in bed each night. Their daytime testosterone levels fell by roughly 10 to 15% compared with their levels after normal sleep.
The second is a 2014 review by Wittert in the Asian Journal of Andrology, which gathered evidence on sleep disorders and testosterone. It described links between lower testosterone and both short sleep and obstructive sleep apnoea, a condition in which breathing repeatedly stops and starts during the night.
Why are doctors talking about it?
Testosterone levels follow a daily rhythm. Much of the rise happens during sleep, and levels are usually highest in the morning, which is why guidelines recommend morning blood tests. It makes biological sense that cutting sleep short, or breaking it up, could affect that rhythm.
The subject also comes up because many men sleep less than they would like, and because sleep apnoea is common in men who are overweight. Symptoms of low testosterone, such as tiredness, low mood and low sex drive, overlap with the effects of poor sleep. Doctors need to tell the two apart.
What does it mean for men?
- Look at sleep first. If you feel tired, flat or less interested in sex, your sleep is worth examining alongside any hormone question.
- Snoring matters. Loud snoring, pauses in breathing noticed by a partner, and daytime sleepiness can suggest sleep apnoea, which a doctor can investigate.
- Test properly. The Endocrine Society guideline recommends diagnosing testosterone deficiency only when there are consistent symptoms and repeated morning blood tests showing low levels.
- Treatment is a medical decision. Whether testosterone therapy is appropriate depends on the full assessment, and a doctor decides.
What we know
- Short-term sleep restriction lowered daytime testosterone in a small group of young healthy men.
- Sleep disorders, especially obstructive sleep apnoea, are associated with lower testosterone.
- Testosterone levels are normally highest in the morning, and testing is timed to reflect that.
What we still don't know
- How far the 2011 result applies. Ten young men in a laboratory for one week is a very small sample. Longer-term effects, and effects in older men, are less clear.
- Which comes first. Obesity is linked with both sleep apnoea and low testosterone, so the Wittert review noted that the relationships are complex and may run in more than one direction.
- Whether better sleep raises testosterone. It is plausible, and better sleep has many other benefits, but it has not been shown to work as a treatment for testosterone deficiency.
For more on why sleep matters beyond hormones, read our piece on sleep and men's health.
Questions men also ask
Can sleep apnoea lower testosterone?
Research has linked obstructive sleep apnoea with lower testosterone, but obesity is common to both, so it is not clear how much is caused by the apnoea itself. A doctor can assess both.
Should I have my testosterone tested if I sleep badly?
Poor sleep alone is not usually a reason for testing. Guidelines recommend testing when there are symptoms of testosterone deficiency, using morning blood samples.
Sources & further reading
- JAMA Effect of 1 week of sleep restriction on testosterone levels in young healthy men (opens in a new tab) (2011) Leproult R, Van Cauter E.
- Asian Journal of Andrology The relationship between sleep disorders and testosterone in men (opens in a new tab) (2014) Wittert G.
- Journal of Clinical Endocrinology & Metabolism Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline (opens in a new tab) (2018) Bhasin S, et al.
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This article is general health information. It does not replace an individual medical consultation, examination or diagnosis. Read our editorial policy and medical review policy.
