Science Vs – “Semen Retention: Should You Stop Ejaculating?”

Host: Wendy Zuckerman (Spotify Studios)
Guests: Suren Jayamana (comedian), Dr. Justin Dubin (urologist/andrologist, Memorial Healthcare System), Dr. Brent Hanson (reproductive endocrinologist, CCRM Fertility)
Date: October 23, 2025

Overview

With “No Nut November” around the corner, Science Vs examines the popular claims about semen retention—abstaining from ejaculation for potential mental, physical, or fertility benefits. Wendy Zuckerman and comedian Suren Jayamana sift through ancient beliefs, booming online communities, and recent scientific research: Does not ejaculating make you mentally sharper, more energetic, or fertile? Or is it all myth and internet hype?

Key Discussion Points & Insights

The Ancient Roots and Modern Hype of Semen Retention

• Cultural Fascination: From ancient Sumerian myths (the god Enki’s ejaculate allegedly creating rivers) to 19th-century doctors warning against masturbation, semen has long fascinated humanity (02:13).
• Online “NoFap” Movement: Cites rapidly growing online communities; over 1 billion views for “semen retention” on social media, but “the least accurate” health topic covered, per Dr. Justin Dubin (09:47).

Top Claims Explored

1. Does Semen Retention Increase Testosterone?

   • A commonly cited study involved 10 men abstaining for 20 days. Result: testosterone stayed the same, only a temporary, minor bump after finally ejaculating (12:42).
   • Wendy: “The only time they saw a little bit of a bump in testosterone levels was after the fellas had their big wank on day 21.” (13:04)
   • Another (since retracted) study suggested a blip after one week, but no consistent evidence supports a lasting increase.
   • Dr. Dubin: “There’s really no good data to suggest that there’s any testosterone boosting benefit to semen retention.” (15:32)

2. Mood, Confidence, and Athletic Performance

   • Many online claim more energy, magnetism, reduced anxiety, etc.
   • Scientific evidence: No significant mood boost, though some report increased self-control (21:30).
   • No meaningful impact on athletic performance, except possible temporary tiredness if sex/ejaculation occurs within two hours of peak performance (19:25).
   • Dr. Dubin: “Most studies do show that there is no impact of sexual activity on athlete performance.” (18:22)
   • Minor psychological effects may stem from a sense of discipline, not physiological change.
   • Wendy: “It definitely feels like it’s more psychological.” (22:47)

3. Does Abstaining Improve Sperm Quality or Fertility?

   • Dr. Brent Hanson reviewed dozens of studies on abstinence impact:
     • Quantity (Sperm Count & Volume): The longer the abstention (up to ~4 days), the larger the sample. After that, benefits plateau (28:24).
     • Quality (Motility, DNA): More frequent ejaculation = healthier, more motile, less damaged sperm. Abstaining for too long (beyond 5–10 days) leads to more DNA fragmentation and abnormally shaped sperm (29:57, 33:07).
     • Optimal window for conception: 2–5 days abstinence before the fertile window. For high DNA fragmentation, even just 1 day (32:39).
     • Wendy: “But as for this idea that… you want to be waiting weeks or months… Brent’s like, if you’re going beyond five days… you’re not doing yourself any favors.” (33:07)

4. Risks of Not Ejaculating

   • No clear health dangers if you choose not to ejaculate (“people who are not sexually active… totally fine.” – Dr. Dubin, 34:24).
   • Slight, inconclusive evidence for a link between frequent ejaculation and lower prostate cancer risk (35:06). But causality unproven.
   • Main psychological risk: Guilt/shame perpetuated by some NoFap online spaces—researchers found increased shame and even suicidality among frequent forum users (36:46).

Notable Quotes & Memorable Moments

• On Online Claims:
  Justin Dubin (10:12):
  “Really, really insanely popular. And by far, the data … was the least accurate.”

• On Testosterone Myths:
  Wendy Zuckerman (12:42):
  “The testosterone levels didn’t change throughout the entire experiment. The only time they saw a little bump in testosterone levels was after the fellas had their big wank on day 21.”

  Dr. Dubin (15:32): “When I look at the research, I think it is pretty clear that holding your semen does not increase your testosterone levels.”

• On Abstinence and Psychological Effects:
  Wendy Zuckerman (22:47):
  “It definitely feels like it’s more psychological.”

• On Motility and DNA Damage:
  Dr. Brent Hanson (30:21):
  “The longer the abstinence period, the more these kind of DNA … errors, so to speak, accumulate.”

• On the Right Abstinence Window:
  Wendy Zuckerman (33:07):
  “If you’re going beyond five days, certainly beyond ten days, you’re not doing yourself any favors.”

• On the Risks of Fap Guilt:
  Dr. Dubin (36:06):
  “A lot of these groups … create guilt. You can have guilt about wanting to ejaculate. You can have stress around not ejaculating.”

  Wendy Zuckerman (36:46):
  “People who hang out more on the NoFap Reddit forums tend to feel more shame, more worthlessness. Some even have suicidal thoughts after ejaculating.”

Important Timestamps

• [00:00–06:32]: Semen retention—history, myths, and modern internet culture.
• [09:11–10:12]: Popularity and accuracy of online semen retention info (Dr. Dubin).
• [10:31–15:32]: Review of research on abstinence and testosterone levels.
• [16:10–19:49]: Claims about mood, energy, and athletic performance.
• [21:30–22:47]: No-fap and mood/self-control studies.
• [23:47–29:01]: Does abstaining improve sperm count and quality? The science.
• [29:43–33:07]: Risks of abstaining too long (DNA damage, motility).
• [34:24–36:46]: Health/mental health risks, prostate cancer research, and social risks from online no-fap communities.

Final Takeaways

• There’s no strong evidence for semen retention boosting testosterone, mood, or athletic performance.
• Abstaining for a few days can bump up sperm quantity, but abstaining too long can harm sperm quality (motility & DNA).
• Optimal abstinence for conception: 2–5 days, or just one day if DNA fragmentation is high.
• No physical harm in abstaining, but online no-fap communities may amplify guilt/shame for some.
• Bottom line: Do whatever works for you—there’s no scientific reason to fear or idolize fapping. You are, indeed, “the master of your domain.”

Speaker Attributions & Tone

The episode is light-hearted, open, with cheeky humor and a focus on evidence over stigma. Wendy is curious and skeptical, Suren is playful and self-deprecating, and the doctors bring a practical, fact-based approach.

For more, including all cited studies, see the episode’s transcript and show notes on Spotify.