Think about the last hour.
You may have checked your phone several times, replied to messages, watched a short video, scrolled through social media, or answered emails. For many of us, screens occupy nearly every part of the day; from work and entertainment to shopping and staying connected.
As screen time has increased, so have questions about its impact on health. One concern that has attracted growing attention is whether excessive smartphone use could affect male fertility or sexual health.
Why has this become a popular topic?
Interest in this subject increased after researchers published a large study in 2023 involving 2,886 young Swiss men. The researchers examined self-reported mobile phone use alongside semen quality measurements.
One finding attracted widespread media attention: men who reported using their mobile phones more frequently had, on average, lower sperm concentration than those who used them less frequently.
At first glance, that sounds alarming. But here's the critical point. The researchers did not conclude that mobile phones directly caused lower sperm counts.
Their study was observational, meaning it identified an association between two variables. Observational studies are valuable for identifying patterns, but they cannot determine whether one factor directly causes another.
Many other variables including sleep quality, stress, body weight, exercise habits, smoking, alcohol consumption, occupational exposures, and overall lifestyle can influence reproductive health.
This important distinction has also been emphasized by healthcare professionals discussing the study. For example, Hims published an article featuring commentary from a urologist, noting that the findings should not be interpreted as proof that smartphones themselves reduce sperm count. Instead, they encouraged readers to view the research within the broader context of men's overall health.
Association doesn't mean causation
One of the biggest challenges in interpreting health research is confusing association with causation.
Imagine researchers observe that people who drink more coffee also report sleeping fewer hours. That doesn't automatically mean coffee is the only reason they're sleeping less. Work schedules, stress, parenting responsibilities, and other lifestyle factors could all contribute. The same principle applies here. The Swiss study found that heavier phone users were more likely to have lower sperm concentration, but it could not determine why.
Scientists call these other influences confounding factors. Some important examples include:
- Sleep duration
- Physical activity
- Body weight
- Smoking
- Alcohol consumption
- Diet quality
- Stress levels
- Occupation
- Environmental exposures
Because these factors often occur together, it's difficult to isolate the effect of smartphone use alone. This is why medical researchers rarely rely on a single observational study to draw firm conclusions.
Does screen time directly affect sperm count?
At present, there is no scientific consensus that everyday smartphone use directly reduces sperm count. Researchers continue to investigate several possible explanations.
One area of interest is whether radiofrequency electromagnetic waves emitted by mobile phones could influence reproductive health. Laboratory studies have explored potential biological effects, but findings have been inconsistent, and human studies have not established a clear cause-and-effect relationship.
Another possibility is that frequent smartphone use simply reflects other lifestyle behaviors that are more strongly linked with reproductive health.
Does screen time affect testosterone?
Testosterone is one of the first hormones people mention when discussing men's health. It's responsible for much more than muscle growth—it also plays a role in libido, mood, energy levels, bone health, and sperm production.
So, can spending hours on your phone lower testosterone?
At present, there is no convincing evidence that everyday smartphone use directly reduces testosterone levels in healthy men.
What researchers do know is that several lifestyle factors commonly associated with excessive screen time may influence hormonal health over time.
Sleep matters more than screens
One of the strongest lifestyle factors linked to healthy testosterone production is sleep. Most testosterone is produced during sleep, particularly during the deeper stages of the sleep cycle. Consistently sleeping too little or having poor-quality sleep has been associated with lower testosterone levels in some studies.
Late-night scrolling can contribute to:
- Delayed bedtimes
- Shorter sleep duration
- Poorer sleep quality for some individuals
- Mental stimulation that makes it harder to unwind
It's important to note that the issue isn't the smartphone itself, it's how prolonged screen use affects sleep habits.
Stress can influence sexual well-being
Modern screen use often means more than simply looking at a display. It can involve constant notifications, work emails after hours, social media comparisons, and an endless stream of information.
Chronic stress activates the body's stress-response system, increasing cortisol levels. Persistently elevated stress may affect mood, motivation, sleep, and relationship satisfaction, all of which can influence sexual well-being. While stress doesn't automatically lead to sexual dysfunction, many men notice changes in libido or intimacy when they're mentally exhausted or overwhelmed.
What about erectile function?
Another common question is whether excessive screen time causes erectile dysfunction (ED). Current research does not show that smartphone use directly causes erectile dysfunction. However, the habits that often accompany excessive screen time may contribute to conditions associated with ED, including:
- Physical inactivity
- Obesity
- Poor cardiovascular health
- Chronic stress
- Anxiety
- Sleep deprivation
Healthy erections depend on several interconnected systems, including blood circulation, nerve function, hormone balance, and psychological well-being.
The bigger picture
If there's one takeaway from the current evidence, it's this; screens are rarely the whole story. Many men who spend long hours on digital devices also experience:
- Less movement throughout the day
- Irregular sleep schedules
- Higher work-related stress
- Increased snacking
- Reduced outdoor activity
- Longer periods of sitting
Over months and years, these habits can affect cardiovascular health, body weight, mental well-being, and energy levels, all of which are important for overall sexual health.
Rather than viewing your phone as the problem, it's more useful to ask whether your daily routine supports long-term health.
Practical habits that can make a difference
The good news is that improving your lifestyle doesn't require giving up technology. Small, consistent changes often have a much greater impact. Consider these evidence-based habits:
- Maintain a consistent sleep schedule.
- Avoid prolonged screen use immediately before bedtime if it interferes with your sleep.
- Take regular movement breaks during long periods of sitting.
- Exercise most days of the week.
- Eat a balanced diet rich in fruits, vegetables, whole grains, healthy fats, and lean protein.
- Maintain a healthy body weight.
- Avoid smoking and limit excessive alcohol consumption.
- Manage stress through relaxation techniques, hobbies, or regular physical activity.
- Seek medical advice if you have persistent concerns about fertility, sexual function, or hormone-related symptoms.
These recommendations are supported by far stronger evidence than any single claim about smartphone use.
When should you speak with a doctor?
Occasional changes in libido or sexual performance are common and can happen for many reasons. However, it's worth consulting a healthcare professional if you experience:
- Persistent erectile difficulties
- Ongoing low sexual desire
- Difficulty conceiving after 12 months of regular unprotected intercourse (or earlier in certain circumstances)
- Symptoms of low testosterone, such as reduced energy, loss of muscle mass, or decreased morning erections
- Significant changes in sexual health that don't improve with lifestyle modifications
A healthcare provider can help identify underlying causes and recommend appropriate evaluation or treatment.
Key takeaways
Current evidence does not show that everyday smartphone use directly causes lower testosterone, erectile dysfunction, or infertility.
What the research does suggest is that excessive screen time often reflects lifestyle habits, such as poor sleep, chronic stress, prolonged sitting, and reduced physical activity; that can influence overall health and may indirectly affect sexual well-being.
The 2023 Swiss study that sparked much of the recent discussion found an association between more frequent mobile phone use and lower sperm concentration, but it did not establish a cause-and-effect relationship. As healthcare professionals, including a urologist featured in a Hims commentary on the study, have noted, the findings should be interpreted within the broader context of overall lifestyle and health rather than as proof that smartphones themselves are harmful.
Your phone may be part of your daily life but your long-term health is shaped by the choices you make around it.
Frequently Asked Questions
Does using a smartphone lower sperm count?
Current research has found associations in some observational studies, but there is no conclusive evidence that everyday smartphone use directly lowers sperm count.
Does screen time reduce testosterone?
There is no convincing evidence that normal smartphone use directly reduces testosterone. Poor sleep and other lifestyle factors associated with excessive screen time may indirectly influence hormonal health.
Can too much screen time cause erectile dysfunction?
No direct causal relationship has been established. However, poor sleep, stress, physical inactivity, and obesity—factors that may accompany excessive screen use—are known to influence erectile health.
Should I stop using my phone to protect my fertility?
There's no evidence that you need to avoid smartphones entirely. Instead, focus on maintaining healthy sleep, regular exercise, balanced nutrition, stress management, and overall healthy lifestyle habits.