Sleep and Testosterone: The Vital Link Between Rest and Hormone Health

Sleep and testosterone are more closely linked than many realise. Testosterone, the hormone best known for regulating male sex characteristics, plays a vital role in overall health for both men and women. From muscle growth and fat distribution to mood and libido, testosterone influences countless biological processes.

And at the core of testosterone production lies one of the most underrated pillars of health: sleep.

In this comprehensive guide, we explore how sleep affects testosterone levels, why testosterone matters for more than just athletic performance, and what poor sleep habits could be doing to long-term hormonal health. Whether the goal is to build muscle, feel more energised, or improve mood and wellbeing, understanding this relationship is key.

What Is Testosterone and Why Does It Matter?

Testosterone is an androgen hormone primarily produced in the testes in men and the ovaries in women, although small amounts are also made by the adrenal glands. While it's often associated with male traits, testosterone is important for everyone.

Key functions of testosterone:

• Promotes muscle mass and strength

• Supports libido and sexual function

• Maintains bone density

• Contributes to red blood cell production

• Regulates fat distribution

• Influences mood and cognitive function

For men, normal total testosterone levels typically range between 10–30 nmol/L (nanomoles per litre), while women naturally have lower levels, ranging from 0.5–3.0 nmol/L.

How Sleep Affects Testosterone Production

Testosterone and the Sleep Cycle

Testosterone production is closely tied to the body’s circadian rhythm, the 24-hour internal clock that regulates sleep and wake cycles. Most testosterone release occurs during deep sleep, particularly in the first REM (rapid eye movement) cycles. This means that disrupted or insufficient sleep can reduce the total amount of testosterone the body produces overnight.

In a landmark study published in the Journal of the American Medical Association (JAMA), researchers found that men who were restricted to just five hours of sleep per night over a one-week period experienced a 10-15% reduction in testosterone levels. Notably, this drop occurred in otherwise healthy, young men aged around 24.

Sleep Duration and Hormone Secretion

The majority of daily testosterone secretion happens during the night, with levels peaking in the early morning. Sleep fragmentation or early waking can interfere with this peak, resulting in suboptimal hormone levels. A consistent 7–9 hours of sleep per night is typically needed for healthy testosterone production.

Shorter sleep durations have been consistently associated with lower testosterone levels, even when other lifestyle factors are controlled. This is particularly relevant in the UK, where over a third of adults report not getting enough sleep.

Symptoms of Low Testosterone Linked to Poor Sleep

When sleep deprivation becomes chronic, it may contribute to symptoms of low testosterone. These include:

• Fatigue and low energy

• Reduced sex drive

• Decreased muscle mass

• Increased body fat

• Mood changes, including irritability and depression

• Poor concentration or memory

These symptoms overlap significantly with those of sleep deprivation, making it difficult to determine whether sleep issues or hormonal imbalance is the primary driver. In most cases, they are interconnected.

The Role of Sleep Disorders Like Sleep Apnoea

Sleep apnoea is a condition where breathing stops repeatedly during sleep, causing disrupted rest and poor oxygenation. It is closely associated with low testosterone, particularly in overweight men.

A study in the journal Sleep found that men with obstructive sleep apnoea (OSA) had significantly lower testosterone levels than those without. Importantly, treating sleep apnoea with CPAP (Continuous Positive Airway Pressure) therapy can help restore hormone levels, improve libido, and boost energy.

This link is particularly relevant for older adults or those with central obesity, where OSA prevalence is higher.

Testosterone and Circadian Rhythm: The Morning Surge

Testosterone naturally rises during the night and peaks in the morning, particularly between 6 a.m. and 10 a.m. Disrupting the circadian rhythm through shift work, jet lag, or irregular sleep patterns can blunt this morning surge, reducing overall daily testosterone availability.

One UK-based study from the Lancet Diabetes & Endocrinology journal found that men with irregular sleep-wake cycles had lower testosterone and poorer sperm quality than those with consistent patterns.

Sleep Deprivation and Age-Related Testosterone Decline

Testosterone levels naturally decline with age, dropping by approximately 1% per year after age 30 in men. However, sleep deprivation appears to accelerate this decline.

Poor sleep may exacerbate age-related testosterone decline, contributing to what is sometimes referred to as andropause—a male equivalent of menopause. Symptoms include reduced strength, libido, and mood, often mistaken for normal ageing.

Maintaining good sleep hygiene may help slow this process and preserve hormone balance later in life.

Can Poor Sleep Lower Testosterone in Women?

Absolutely. While women produce less testosterone, the hormone still plays key roles in energy, libido, and mood. Sleep deprivation can affect hormonal balance in women too, potentially impacting not just testosterone but also oestrogen, progesterone, and cortisol.

Some studies suggest that chronic sleep issues may worsen symptoms of PCOS (polycystic ovary syndrome), a condition where women have elevated androgens, menstrual irregularities, and insulin resistance.

How to Improve Sleep for Better Testosterone

Improving sleep quality and duration is one of the most effective natural strategies for optimising testosterone levels. Here are some science-backed strategies:

1. Prioritise Sleep Duration

Aim for 7–9 hours of quality sleep each night. This is the sweet spot for most adults when it comes to maintaining hormonal balance.

2. Keep a Regular Sleep Schedule

Going to bed and waking up at the same time daily reinforces the circadian rhythm and promotes a healthy testosterone cycle.

3. Create a Sleep-Friendly Environment

Use blackout curtains, reduce noise, and maintain a cool bedroom temperature (~18°C) to improve sleep depth.

4. Cut Out Blue Light Before Bed

Avoid screens at least 60–90 minutes before bedtime, as blue light suppresses melatonin and delays sleep onset.

5. Reduce Alcohol and Caffeine

Alcohol and caffeine both interfere with deep sleep, which is critical for testosterone release.

6. Manage Stress Levels

Chronic stress elevates cortisol, a hormone that inhibits testosterone. Relaxation techniques such as mindfulness, journaling, or light yoga can help.

7. Try Natural Sleep Aids

Supplements such as magnesium, valerian root, and chamomile have been shown to improve sleep quality. Many of these double as vitamins for sleep, which may indirectly support hormonal balance.

8. Exercise Regularly (But Not Too Late)

Strength training and moderate aerobic exercise can boost testosterone. Just avoid intense workouts too close to bedtime, which may delay sleep onset.

Testosterone Therapy and Sleep: What to Know

For those diagnosed with clinically low testosterone, testosterone replacement therapy (TRT) may be prescribed. However, it’s important to note that TRT can have mixed effects on sleep. Some men report improved energy and sleep, while others experience worsened apnoea or restlessness.

If starting TRT, especially in the UK, monitoring by an NHS endocrinologist or private clinic is essential. Always address sleep quality alongside hormone treatment.

Lifestyle Habits That Support Both Sleep and Testosterone

Many everyday behaviours affect both sleep and testosterone simultaneously. These include:

• Eating a nutrient-dense diet rich in zinc, vitamin D, and healthy fats

• Avoiding late-night heavy meals

• Keeping evening stress low

• Getting daily sunlight exposure

• Maintaining a healthy weight

Together, these factors form a virtuous cycle where good habits improve sleep, which in turn supports healthy hormone production—and vice versa.

When to Seek Help for Sleep or Testosterone Issues

Persistent fatigue, mood swings, poor libido, and muscle loss shouldn’t be dismissed as just stress or ageing. It may be worth:

• Requesting a blood test from a GP to check testosterone levels

• Undergoing a sleep study if apnoea or insomnia is suspected

• Seeking nutritional advice to optimise dietary intake

In the UK, testosterone testing and sleep assessments are available on the NHS, though private services may offer quicker access.

Final Thoughts: Protect Sleep to Protect Testosterone

The relationship between sleep and testosterone is undeniable. Whether aiming to build strength, maintain a healthy libido, or simply feel energised, prioritising good-quality rest is one of the most powerful steps to take.

With so much testosterone production happening at night, consistent sleep habits aren’t just a wellness trend—they’re essential hormone therapy, no prescription required.