Boxers or briefs: Study finally settles whether a man’s underwear really affects his fertility

Live updates

1. 1h ago

   Large study finds no link between underwear type and male fertility

   A study of nearly 27,000 men has found no significant difference in sperm quality between those who wear boxers and those who wear briefs. Researchers concluded that underwear choice does not meaningfully affect male fertility outcomes. The analysis, described as the largest of its kind, challenges long-standing advice for men to switch to loose-fitting underwear when trying to conceive.

   Why it matters

   For decades, medical guidance has suggested that tight underwear raises scrotal temperature and impairs sperm production. This recommendation has been based on smaller studies and physiological theory rather than large-scale epidemiological evidence. The new findings suggest that lifestyle factors other than underwear choice may be more relevant for couples trying to conceive.

   What is confirmed

   • A study of nearly 27,000 men examined the relationship between underwear type and sperm quality.
   • The study found no significant difference in sperm quality between men who wear boxers and those who wear briefs.
   • Researchers concluded that underwear choice does not meaningfully affect male fertility.

   Still unconfirmed

   • Tight underwear may be linked to erectile issues.
   • Underwear choice affects pregnancy outcomes.

   What to watch next

   • Publication of the full peer-reviewed study methodology and data
   • Response from fertility clinics on whether they will update clinical guidance
   • Further research on other lifestyle factors affecting male fertility
   Sources used for this update (5)

   1. New York Post — Boxers or briefs: Study finally settles whether a man’s underwear really affects his fertility
   2. ScienceAlert — Study of Nearly 27,000 Men Is The Largest Yet on Tight Underwear And Sperm Quality
   3. Наша Ніва — Do tight underwear harm? The largest study
   4. The Sun — Morning mistake ruining your sex life? How erectile issues link to common choice
   5. dw.com — Underwear & pregnancy
   confidence 85%