#351 ‒ Male fertility: optimizing reproductive health, diagnosing and treating infertility, and navigating testosterone replacement therapy | Paul Turek, M.D.
Dr. Paul Turek, a male fertility expert, discusses the complex process of conception, factors impacting sperm quality (heat, stress, toxins), and strategies for optimizing male reproductive health, including TRT and emerging technologies.
Deep Dive Analysis
19 Topic Outline
Introduction to Male Fertility and Conception Challenges
The Complex Journey of Sperm to Fertilize an Egg
Sperm Production: Meiosis, Genetic Variation, and Renewal
Sperm Maturation: Tail Formation, Motility, and Chemical Sensing
Optimizing Conception: Timing of Sex and Ejaculation Frequency
Defining Male Infertility and Diagnostic Approach
Impact of Viral Infections on Testicular Health
Understanding Semen Analysis Parameters
Effects of Lifestyle, Toxins, and Stress on Fertility
Testosterone Replacement Therapy (TRT) and Fertility Impact
Strategies for Restoring Fertility After TRT Use
Influence of Heat and Cold Exposure on Sperm Quality
Impact of Exercise and Cycling on Male Fertility
Effects of Alcohol, Marijuana, and Nicotine on Male Fertility
Type 2 Diabetes and Varicoceles as Causes of Infertility
Genetic Factors Affecting Male Fertility
Debunking Stem Cell and PRP Therapies for Infertility
Considerations for Sperm Banking and Paternal Age Risks
Semen Quality as a Biomarker for Longevity and Health
7 Key Concepts
Meiosis
A specialized cell division process in the testicle that produces sperm with half the number of chromosomes, allowing for genetic recombination and variation, unlike mitosis which creates identical cells.
Spermiogenesis
The profound transformation of a round cell into a fully formed sperm, including the development of a tail and motor assembly, a process that takes about three weeks.
Blood-Testis Barrier
A highly protective barrier within the testicle, similar to the blood-brain barrier, that insulates the developing sperm from most external exposures, including many viruses and toxins.
Epididymis
A 35-foot long collecting duct located on the back of the testicle where sperm mature over 10-14 days, gaining progressive motility and the ability to chemically sense follicular fluid.
Aneuploidy
A condition where a cell has an abnormal number of chromosomes (e.g., missing one or having an extra), which can occur during sperm production but is largely filtered out before ejaculation.
Varicocele
Varicose veins in the scrotum, typically on the left side, caused by reflux of blood due to a lack of valves in the testicular vein, which can increase testicular temperature and impair sperm quality.
Secondary Hypogonadism
A condition where low testosterone is caused by a signaling issue from the brain (hypothalamus/pituitary) rather than primary testicular failure, often due to stress or other systemic factors.
14 Questions Answered
It is an incredibly complex and hostile journey; out of about 100 million ejaculated sperm, only about 5 million make it past the cervix, 100-500 reach the fallopian tube, and typically only one fertilizes the egg.
It takes an average of 74 days for a sperm to be fully made in the testicle and mature through the epididymis before ejaculation.
Having sex every other day is generally recommended to optimize conception, with front-loading intercourse before ovulation being more effective than reacting to ovulation.
An egg is viable for fertilization for approximately eight hours after ovulation, making timely intercourse crucial.
Infertility is defined as one year of inability to conceive after regular unprotected sex.
A comprehensive workup includes a thorough medical history, a physical exam (checking for issues like varicoceles or absent vas deferens), a semen analysis, and hormonal evaluation (LH, FSH, testosterone).
Exogenous testosterone typically suppresses natural sperm production, leading to sterility in about 95% of men while on therapy, though some physiological dosing strategies may preserve some function.
Recovery is often possible, especially in younger men, but depends on the dose, duration, and method of testosterone use. Tapering off testosterone and using medications like Clomid or HCG can aid recovery.
Hot baths and hot tubs (104°F for 20 minutes, three times a week) can significantly impair sperm quality, reducing total motile count by up to 300-600%; saunas have a lesser but still noticeable effect, while cold plunges are generally not a concern.
Extreme exercise, such as two hours a day at 80% maximum VO2 capacity, can significantly reduce sperm counts and testosterone levels, but moderate exercise is generally beneficial.
Alcohol, especially when abused, can directly poison sperm and cause hormonal imbalances. Marijuana (THC) is a 'bad actor' that negatively impacts sperm count, motility, morphology, and fragmentation, with chronic use potentially linked to testicular cancer. Nicotine also has negative effects on sperm count and motility.
A varicocele is a common condition involving varicose veins in the scrotum that can impair sperm quality due to increased temperature. It is diagnosed by physical exam and can be surgically repaired as an outpatient procedure.
While there's a slow linear increase in risk from age 25 to 50 or 60, there's a significant inflection point after age 60, with increased risks for miscarriages, birth defects, and neurodevelopmental conditions like autism and schizophrenia.
Sperm freezing is a very old and reliable technology; a good sample typically sees about half of the sperm survive the freezing and thawing process.
26 Actionable Insights
1. Avoid Exogenous Testosterone Monotherapy
If you are taking exogenous testosterone and wish to preserve fertility, you must combine it with HCG (250-500 units twice a week) and maintain at least 95% compliance. Unopposed testosterone, especially injections, will suppress sperm production in 95% of men.
2. Taper Testosterone Cessation
When discontinuing exogenous testosterone, never stop suddenly to avoid severe fatigue and discomfort. Instead, taper the dose over approximately six weeks (e.g., halve the dose for two weeks, then halve again for two weeks, then off for two weeks) to allow the body’s natural production to reactivate more smoothly.
3. Support TRT Recovery with Clomid/HCG
To aid recovery after stopping testosterone, consider using Clomid or Enclomiphene to stimulate pituitary function, or more aggressively, HCG and Clomid, which can accelerate the return of natural testosterone and sperm production.
4. Monitor Hemoglobin/Hematocrit on TRT
If you take exogenous testosterone, you are at risk for polycythemia (blood thickening). Monitor hemoglobin and hematocrit, as levels above 17 and 50 respectively, increase the risk of adverse events like blood clots.
5. Daily Microdosing to Avoid Polycythemia
To mitigate the risk of polycythemia from testosterone injections, consider daily microdosing (e.g., 10-15 milligrams daily) instead of less frequent, larger doses, as this avoids high peaks that stimulate red blood cell production.
6. Avoid Hot Tubs and Prolonged Hot Baths
Submerging the testicles in hot water significantly impairs sperm quality. Spending 20 minutes in a 104-degree hot tub three times a week can reduce sperm count to zero, primarily affecting motility. Eliminate or severely limit exposure to hot tubs and hot baths.
7. Limit Sauna Exposure for Fertility
While less severe than hot tubs, saunas can still negatively impact sperm quality, with an effect estimated to be one-quarter to one-third as profound as hot water submersion. Consider reducing sauna time if trying to conceive.
8. Manage Stress for Reproductive Health
Chronic stress significantly lowers testosterone levels and, consequently, sperm production. Engage in stress-reducing activities like running, walking, or other physical activities to decompress and support hormonal balance.
9. Avoid Marijuana Use for Fertility
Marijuana (THC) is a ‘bad actor’ for male fertility, negatively impacting sperm count, motility, and morphology. It also has a depot effect, remaining in fat for weeks, leading to chronic low-level toxicity, and is associated with an increased risk of testicular cancer.
10. Limit Alcohol Consumption for Fertility
Alcohol is a direct toxin to the testicles, affecting sperm count, motility, and morphology. Excessive alcohol use also increases estrogenization, leading to lower testosterone. Limit intake to less than two glasses per day.
11. Avoid Nicotine for Fertility
Nicotine, whether synthetic or from tobacco, is a ‘bad actor’ at high doses, negatively affecting sperm count and motility. It is believed to act as an oxidant, damaging sperm.
12. Address Obesity and Poor Diet
Obesity and a ’lousy diet’ are significant lifestyle factors that negatively impact male fertility, primarily through endocrine system disruption and other metabolic issues. Focus on improving metabolic health through diet and lifestyle.
13. Avoid Chronic Extreme Exercise
While moderate exercise is beneficial, chronic extreme exercise (e.g., two hours daily at 80% VO2 max) can significantly reduce sperm counts and testosterone levels. Ensure exercise intensity is balanced if trying to conceive.
14. Get a Comprehensive Male Fertility Workup
If struggling with infertility, ensure both partners are evaluated simultaneously. For men, a thorough workup should include a detailed history (including exposures), physical exam, at least two semen analyses, and hormone checks (LH, FSH, Testosterone, Estradiol).
15. Avoid Single Semen Analysis Decisions
Semen analysis parameters can vary by 50-100%, so never make a diagnosis or treatment decision based on a single sample. Always obtain at least two semen analyses, typically three weeks apart, for accurate assessment.
16. Front-Load Sexual Intercourse for Conception
To optimize the chances of conception, engage in sexual intercourse before ovulation (e.g., days 9, 11, 13 of a cycle if ovulation is day 15). Sperm can survive for days in the female reproductive tract, while an egg is only viable for about eight hours post-ovulation.
17. Optimize Sex Frequency for Conception
For couples trying to conceive, having sex every other day is generally recommended as the optimal interval to ensure a fresh supply of sperm is available for ovulation.
18. Optimize Semen Analysis Abstinence
For diagnostic semen analysis, abstain from ejaculation for two to four days. Longer abstinence may increase sperm count but decrease motility due to older sperm, while shorter abstinence may yield lower counts.
19. Address Varicoceles if Present
If a varicocele (varicose veins in the scrotum) is identified and is contributing to infertility, surgical repair is a common and effective treatment, with two-thirds of men improving and many conceiving naturally post-procedure.
20. Avoid Toxic Environmental/Workplace Exposures
Be wary of exposure to ‘smelly solvents,’ airport fuels, machine shop oils, and benzene derivatives, as these environmental toxins can negatively impact male fertility. Take steps to reduce or eliminate such exposures.
21. Treat Infections Promptly
Infections, particularly those causing pus cells (pyospermia) in semen or the urinary tract, can be destructive to sperm and significantly lower motility. Prompt diagnosis and treatment of such infections are crucial for fertility.
22. Ensure Proper Bicycle Saddle Fit
If you experience pelvic numbness while cycling, invest in a better saddle. The ideal saddle should be flat or gel in the back, cut out in the middle, and designed to support the sit bones rather than putting pressure on the perineum, to prevent erection issues.
23. Consider Sperm Banking Before Cancer Therapy
Any male undergoing chemotherapy or radiation for cancer should strongly consider banking sperm, regardless of age or perceived fertility. This is a crucial precaution as cancer treatments can severely impair or eliminate future sperm production.
24. Consider Sperm Banking for Advancing Paternal Age
While not as dramatic as female age, paternal age (especially over 40, and significantly over 60) is associated with increased risks to offspring, including miscarriages, birth defects, and neurodevelopmental issues like autism. Banking sperm at a younger age can mitigate these risks.
25. Bank Sufficient Sperm Samples
For sperm banking, aim for at least three ejaculates if normal, which is typically sufficient for one child using IUI. Ten ejaculates can provide enough sperm for multiple children using IUI or many IVF cycles.
26. Recognize Fertility as a Health Biomarker
Understand that male fertility is a biomarker for overall health and longevity. Men with normal semen quality tend to live longer, providing an opportunity for preventative medicine and early detection of other health issues.
9 Key Quotes
So it's an interesting challenge that nature has kept in place for a million years, and I really respect evolution. And it is why we're here for, you know, eat, sleep, reproduce.
Paul Turek
So it's like a run up the middle. And then eventually a couple of sperm or fourth make it and the immune system's deactivated and they get there. It's wild.
Paul Turek
One of the most magnificent transformations of a cell in the body is the making of a sperm.
Paul Turek
I think what I would like to emphasize in this podcast is how fluid evolution actually is. And it's sperm-driven and it's transgenerational.
Paul Turek
I think the stress counterbalances any amount of microplastics you save.
Paul Turek
Do you want fertility when you're running for your life? In any species? No, you're trying to save your life. So cortisol goes on. Testosterone is nowhere to be found. Fertility is nowhere.
Paul Turek
The effect of testosterone muscle mass is indirect. It's not that you're going to do it and create mass. You don't just create mass. What it allows you to do is recover from injury.
Paul Turek
So if you ask me, what's the reason our sperm counts are falling? I would say we stood up as a species.
Paul Turek
I'm really happy that we're scaring couples to realize that their fertility is a measure of their health.
Paul Turek
4 Protocols
Optimizing Conception Timing
Paul Turek- Front-load intercourse before ovulation.
- Have sex every other day, especially starting around day 9-11 of the female cycle if ovulation is day 15.
- Do not wait until ovulation to have sex, as the egg is only viable for about 8 hours post-ovulation.
Male Infertility Diagnostic Approach
Paul Turek- Complete a thorough medical history, often using a detailed questionnaire.
- Perform a physical exam to check for major medical issues, varicoceles, or congenital anomalies like absent vas deferens.
- Conduct at least two semen analyses, three weeks apart, to account for variability.
- Evaluate hormone levels, including LH, FSH, and testosterone, to assess signaling and production.
Restoring Fertility After Exogenous Testosterone Use
Paul Turek- Never stop testosterone suddenly; instead, taper the dose over approximately six weeks (e.g., half dose for two weeks, then half again for two weeks, then off for two weeks).
- Consider using Clomid or Enclomiphene during the taper to help reactivate the pituitary and soften the fatigue.
- For a more aggressive approach, use HCG and Clomid to stimulate natural production and protect fertility.
- Check testosterone levels around two weeks after the last testosterone dose to predict recovery, and allow more time for full recovery.
Maintaining Fertility While on Exogenous Testosterone (Dual Therapy)
Paul Turek- Combine low-dose exogenous testosterone (e.g., daily nasal or twice-daily oral) with HCG (250-500 units twice a week).
- Maintain 100% compliance with both therapies, as missing HCG doses can quickly lead to zero sperm count.
- Note that Clomid is not effective for maintaining intratesticular testosterone levels in this context.