Testosterone And Rem Sleep: What's The Connection?

Sleep and testosterone are closely linked. Testosterone levels vary during the day and are highest during sleep. Sleep deprivation can reduce testosterone levels by 10-15% in healthy young men.

Testosterone is a sex hormone found in both men and women. In men, it is mainly produced in the testicles and affects muscle and bone strength, libido, brain function, and hair growth. Low testosterone can cause low energy, reduced libido, poor concentration, and increased sleepiness.

Testosterone levels are linked to the body's circadian rhythm, with levels rising as one falls asleep and peaking during the first REM sleep cycle. REM sleep is important for testosterone production as it is when the brain is most active, consolidating information and getting ready to wake up.

Therefore, a lack of sleep or disrupted sleep can negatively impact testosterone levels. However, the relationship between sleep and testosterone is bidirectional, as low testosterone can also disrupt sleep.

Testosterone levels and sleep duration

Sleep and testosterone are closely linked. Testosterone levels vary during the day and are highest during sleep. Sleep deprivation can reduce testosterone levels by 10-15% in healthy young men.

The Science Behind It

Testosterone levels are linked to the body's circadian rhythm, which is the regular body changes over a 24-hour period. During sleep, testosterone levels rise, peaking between 7 a.m. and 10 a.m., and reaching a low point in the mid-afternoon.

The first three hours of sleep are important as it takes, on average, around this long for men to reach the first REM cycle. However, normal sleep throughout the night is also needed to maintain testosterone production.

Rapid Eye Movement Sleep

Rapid eye movement (REM) sleep is the part of sleep where the brain is most active, and the eyes move quickly, despite being closed. It is during this time that you are most likely to dream, and your body functions similarly to when it is awake.

The Impact of Sleep Deprivation

If you are not getting enough sleep, or your sleep is disrupted, you may not progress into the REM sleep cycle. This can disrupt your body's production of testosterone.

One study found that young, healthy men who slept for only five hours a night had a 10-15% reduction in testosterone production. Lower levels of testosterone were associated with mood changes and lower energy levels.

A Two-Way Street

The relationship between sleep and testosterone is a two-way street. Poor sleep can affect the production of testosterone, but low testosterone can also disrupt sleep. Several studies have shown that low testosterone negatively affects sleep in both older and younger men.

Tips for Improving Sleep

• Stick to a set sleep routine
• Ditch the screen before bed
• Make your bedroom comfortable
• Avoid food and certain drinks before sleep
• Make yourself tired during the day

REM sleep and testosterone production

Testosterone levels in men vary during the day and are highest during sleep. A healthy amount of sleep is needed for the body to produce testosterone. However, a lack of sleep or disrupted sleep can negatively impact testosterone levels.

The Link Between Testosterone and Sleep

Testosterone levels are linked to the body's circadian rhythm – regular body changes over a 24-hour period. During sleep, testosterone levels begin to rise, peaking between 7 am and 10 am, and reaching a low point in the mid-afternoon. Levels slowly rise once a person falls asleep and rapidly increase during the first REM cycle.

REM Sleep and Testosterone

REM sleep is the part of sleep where the brain is most active. The eyes move quickly (although they are closed) and it is when people are most likely to dream. During REM sleep, the body functions similarly to when it is awake. The brain consolidates information and gets ready to wake up.

The first three hours of sleep are important as this is the average time it takes for men to reach the first REM cycle. However, normal sleep throughout the night is also needed to maintain testosterone production. If someone is not sleeping long enough or is waking up frequently, they may not enter REM sleep. This can disrupt the body's production of testosterone.

Lack of Sleep and Testosterone

A study found that young, healthy men who slept for only five hours a night had a 10-15% reduction in testosterone production. Lower levels of testosterone were associated with mood changes and lower energy levels. Both a lack of sleep and disrupted sleep can negatively impact testosterone levels.

Sleep Disturbance and Hypogonadism

The relationship between sleep and testosterone is bidirectional. Poor sleep can affect testosterone production, but low testosterone can also disrupt sleep. Studies have shown that low testosterone negatively affects sleep in both older and younger men. Poor sleep may indicate an issue with low testosterone, or hypogonadism, where the testicles are not producing enough testosterone. With testosterone replacement therapy, sleep quality usually improves.

Sleep disorders and testosterone

Sleep disorders such as abnormalities in sleep quality, duration, circadian rhythm disruption, and sleep-disordered breathing can lead to a decrease in testosterone levels. For example, sleep restriction and deprivation have been shown to lower testosterone levels, with the effect potentially being more significant in older individuals.

Obstructive Sleep Apnea (OSA) is a common sleep disorder that does not directly affect testosterone levels. However, it can indirectly impact testosterone through its association with obesity. Treatment of moderate to severe OSA with Continuous Positive Airway Pressure (CPAP) has not been consistently shown to increase testosterone levels. In contrast, weight loss has a predictable and linear relationship with increased testosterone levels.

Testosterone levels can also influence sleep quality. Both insufficient and excessive testosterone levels can disrupt sleep, with low testosterone levels being associated with reduced sleep efficiency, more nocturnal awakenings, and less slow-wave sleep. Additionally, large doses of exogenous testosterone and anabolic/androgenic steroid abuse are linked to abnormalities in sleep duration and architecture.

Age, obesity, and sleep

Age

Middle-aged men secrete less testosterone at night than young, healthy men. This may be due to the fact that, from middle age onwards, less time is spent in the deeper phases of sleep, and there is more stage I sleep and more awakenings. The effect of ageing on REM sleep is variable, and it tends to be preserved until quite late in life.

Obesity

Obstructive sleep apnea (OSA) is a sleep disorder that is commonly associated with obesity. While it is often asserted that OSA directly causes a decrease in pituitary-gonadal function and, therefore, testosterone levels, evidence suggests that this is not the case. Rather, it is the obesity that is the primary determinant of testosterone levels in men with OSA. In severely obese men with a body mass index (BMI) of 35 or more, the severity of OSA was inversely related to free testosterone levels.

Sleep

Testosterone levels typically increase during sleep as part of a natural 24-hour cycle of rising and falling levels. Sleep deprivation and sleep disorders can cause a decrease in testosterone levels. Studies have shown that a week of sleeping less than five hours per night was linked to a 10-15% decrease in testosterone levels in healthy young men. Sleep disorders such as OSA can also cause a reduction in testosterone levels, although this may be due to the associated weight gain rather than the disorder itself.

Testosterone replacement therapy

Who is TRT for?

TRT is typically recommended for people whose blood tests confirm they have low testosterone levels and are experiencing related symptoms. In men, these can include sparse facial and body hair, erectile dysfunction, fatigue, loss of lean muscle mass, and a low sense of well-being. Women may be prescribed TRT if they have a low libido, although other causes are usually explored first.

Benefits of TRT

TRT can improve energy levels, sex drive, and mood. It can also increase bone density, muscle mass, and insulin sensitivity.

Risks and side effects of TRT

While TRT can have benefits, it also carries risks and side effects. These include:

• Skin irritation where the testosterone is applied topically
• Decreased sperm count
• Increased red blood cell count, which can raise the risk of blood clots
• Increased risk of prostate cancer and benign prostatic hypertrophy (BPH)
• Worsening of sleep apnea
• Irregular heartbeat
• Kidney problems

Forms of TRT

TRT is available in several forms, including:

• Skin patches worn on the arm, upper body, or another part of the body where sweating or pressure are unlikely
• Gels applied directly to the skin once a day
• Nasal gels applied to the inside of the nose three times a day
• Mouth patches that stick to the upper gums and continuously release testosterone into the bloodstream
• Injections, either administered by a healthcare professional or self-administered at home
• Implants, which involve pellets inserted under the skin every 3 to 6 months
• Pills, which are typically more expensive and may not be covered by insurance

Frequently asked questions