Decoding Male Reproductive Health and The Fertility Testing Playbook

Understanding Male Infertility: The Overlooked Half of the Equation

Infertility is not just a women’s issue–men contribute to 50% of infertility cases in the U.S. But, many are unaware that hidden hormonal imbalances could be affecting their ability to conceive. Without proper testing, these imbalances often go undiagnosed, leaving couples frustrated and uncertain about what to do next.

But, hormonal imbalances and male infertility share similar symptoms, making it critical to rely on data rather than symptoms. Lab testing is key to knowing precise hormone levels and which nutrients may improve fertility in men, while monitoring those biomarkers allows you to pinpoint areas of improvement–helping you to potentially reduce your timeline to conception.

Symptoms to watch:

• Lower sex drive
• Hair loss
• Mood changes
• Changes in body composition
• Altered sexual function (e.g., erectile dysfunction)
• Fatigue

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The Role of Hormones

Hormones are fundamental to male reproductive health. In men, they regulate sperm production and quality, libido (sex drive), and overall fertility.

1. Testosterone & Estradiol (E2)

Testosterone (both free and total testosterone) is essential for sperm development, but too much of it is a problem. Excess testosterone is converted into estradiol (E2), a hormone often linked to female health. But, for males, having elevated levels of estradiol (E2) has been associated with lower sperm production, testicular shrinkage, and reduced sex drive.

2. Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH)

Follicle-Stimulating Hormone (FSH) helps the testes produce sperm by stimulating cells called Sertoli cells. Low FSH levels can mean there's a problem with sperm production, while high levels could show testicular failure or damage. Another important hormone, Luteinizing Hormone (LH), signals the testes to make testosterone. If LH levels are off, testosterone production can drop, leading to lower sperm count and quality.

3. Prolactin

Prolactin, another hormone often associated with women for its role in milk production, is key for male reproductive health. High prolactin levels, a condition known as hyperprolactinemia, can actually suppress testosterone production and cause decreased sperm production, erectile dysfunction, and low sex drive.

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Thyroid function is also important for fertility. An underactive (hypothyroidism) or overactive (hyperthyroidism) thyroid can cause problems, like low sperm motility, sperm with DNA damage, and lower sperm count. Men with untreated thyroid issues often have fertility struggles, too.

Hormonal imbalances can look like common symptoms: fatigue, mood changes, and weight gain, comprehensive lab testing is the key to unlocking real answers. By identifying and addressing these imbalances early, men–alongside their partners–can significantly improve their reproductive potential and overall health.

Biomarkers to Test

When it comes to fertility testing in men, these are the biomarkers to watch if you want a comprehensive look at reproductive health.

1. Sex Hormones

Sex hormones are the foundation of male fertility–these reproductive hormones play a crucial role in sperm production and overall male fertility.

• Testosterone (Total & Free) – Essential for sperm production and libido.
• Follicle-Stimulating Hormone (FSH) – Stimulates the development of sperm (spermatogenesis).
• Luteinizing Hormone (LH) – Stimulates testosterone production.
• Estradiol (E2) – High levels may negatively impact male fertility.
• Prolactin – Elevated levels can impair testosterone and sperm production.
• Dehydroepiandrosterone Sulfate (DHEA-S) – A precursor hormone to testosterone.
• Sex Hormone Binding Globulin (SHBG) – Helps to regulate the amount of free (bioavailable) testosterone levels.

2. Thyroid Function

Thyroid hormones regulate metabolism and energy–but in men they also influence fertility, as well as sperm shape and motility.

• Thyroid Stimulating Hormone (TSH) – Stimulates the thyroid gland to release thyroid hormones.
• Triiodothyronine (T3) Free & Thyroxine (T4) Free – Key thyroid hormones involved in regulating metabolism.
• Thyroglobulin Antibodies (TgAb) & Thyroid peroxidase antibodies (TPO) – Can indicate autoimmune thyroid diseases.

3. Nutrient Levels

Nutrient deficiencies are often overlooked–but they play a critical role in healthy sperm production. Advanced lab testing can identify key gaps that may be affecting fertility and your chances of conception.

• Vitamin D – Supports testosterone and sperm function.
• Iron & Ferritin – Essential for sperm motility, energy, and DNA quality, but too much iron is harmful to these factors.
• Magnesium & Zinc – Critical for hormone regulation and sperm motility.
• Homocysteine – High levels can lead to inflammation and oxidative stress, which negatively affects fertility.

4. Stress Markers

Chronic stress can significantly harm men’s fertility and reproductive health. Persistent stress is associated with reduced sperm production, motility, and viability, as well as lower testosterone levels and sperm DNA damage.

• Cortisol – Our primary stress hormone; prolonged elevation leads to hormone imbalances.
• Dehydroepiandrosterone-Sulfate (DHEA-S) – DHEA-S is a precursor to testosterone and may have a protective role during an acute stress response.

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Men’s Fertility Testing: How Often Should You Test?

In both women and men, hormonal fluctuations can be normal. But, for those trying to conceive, lab testing every 3-6 months along the way can help provide direction and key insights into your reproductive health.

Especially in men over 30, testosterone levels begin to decline by about 1% per year—a gradual drop that can impact fertility, energy, and overall hormonal balance. Consistent monitoring in this way helps you to identify trends and potential issues before they become major roadblocks.

How to Improve

So, let’s say your test results indicate some hormonal imbalances. What next? There are several proactive steps you can take to improve your fertility and support reproductive success. Alongside personalized insights from top doctors with Function lab testing, some general rules of thumb are as follows:

1. Focus On Nutrition

A nutrient-dense fertility diet for men should include:

• Omega-3 fatty acids found in fatty fish, like wild-caught salmon or sardines, flaxseed or chia seeds, and walnuts.
• Antioxidants found in rich, pigmented organic fruits and vegetables.
• Zinc & selenium from nuts and seeds, like Brazil nuts and pumpkin seeds.
• Adequate high-quality protein from lean meats, pasture-raised eggs, and legumes.

2. Reduce Stress & Improve Sleep

High cortisol levels from chronic stress or sleep deprivation can impair or suppress testosterone production. And improved sleep quality is linked to better cortisol regulation. 

• Improved sleep is closely associated with a balanced circadian rhythm, which starts with maintaining a consistent sleep schedule. Other factors affecting your sleep and, in turn, your fertility, is light exposure–both upon waking, as well as in the evenings–device use, and environmental temperature.
• Progressive muscle relaxation (PMR), where you focus on tensing and releasing whole muscle groups at a time, can be another effective stress-reduction tactic. 
• Get outside in nature for even just a short amount of time, like a 20-30 minute walk in a park or natural setting, to significantly reduce stress.

3. Exercise in Moderation

Exercise in moderation positively affects male fertility–in whichever form of movement you prefer:

• Moderate-intensity aerobic exercise has been shown to enhance sperm motility, improve blood and oxygen flow to the testes, and support optimal sperm development.
• Resistance training has proven to increase testosterone levels, in turn supporting spermatogenesis (the process of producing sperm cells), and potentially contributes to higher sperm quality when combined with a nutrient-dense diet.
• High intensity interval training (HIIT) was shown to increase testosterone levels by about 17% in previously sedentary males.

There are benefits to combining exercise methods, but moderation is key. Excessive or high intensity training has been shown to have negative effects on male fertility.

4. Limit Toxin Exposure

Environmental toxins can seem unavoidable in our modern world–from plastics, to pesticides, and processed foods, all of which can disrupt endocrine function. 

• Opt for organic foods
• Avoid PFAS in non-stick cookware
• Use BPA-free food storage containers
• Drink filtered water 

5. Supplementation

There’s no one size fits all when it comes to supplementation, and the same goes for the best fertility supplements for men. Incorporating supplements or vitamins for men’s fertility should be individualized and based upon your personal health status. Test your biomarkers with Function to understand what the root causes of hormonal disruption may be and which areas need the most support.

Cost of Testing

Comprehensive lab testing can cost thousands of dollars individually. But, that’s why Function exists. To give you access to 100+ lab tests, including essential male hormones, nutrients, thyroid, and stress lab tests needed to intentionally track and monitor your reproductive health. Alongside actionable insights from top doctors for further guidance, at a fraction of the cost.

Takeaway

Understanding fertility and infertility is complex. It cannot simply be determined by an at-home fertility test for men. For a process as complex as fertilization, it requires a whole-body approach–a deeper understanding of what’s going on inside of your body. Without clear data, it’s nearly impossible to differentiate between hormonal imbalances and fertility issues.

Comprehensive lab testing puts you in control. Leverage comprehensive lab testing and in-depth clinical insights to take informed steps towards optimizing your reproductive health. Whether you’re actively trying to conceive or preparing for the future, investing in hormone testing today can make all the difference in your timeline to becoming a parent.

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