02/02/2026
Did you know your underwear choice could be impacting fertility?
A growing body of research suggests that what you wear underneath your clothes — especially polyester and other synthetic fabrics — may influence reproductive health, particularly in men. Although underwear isn’t the sole or primary cause of infertility, evidence points towards several mechanisms by which fabric type might affect s***m health and testicular function. The topic is now being discussed in the context of broader reproductive research, such as reviews in Human Reproduction Update (2026) and related studies.
Here’s what the science says:
🔥 Heat and S***m Health
The te**es need to stay a few degrees cooler than core body temperature to produce healthy s***m. Polyester and similar synthetic fabrics are less breathable than natural fibers, which may trap heat near the sc***um — a condition known to impair s***m production and motility.
⚡ Electrostatic Effects on Testicular Function
Some older experimental studies found that polyester fabrics can generate electrostatic charges when they rub against skin. These fields were hypothesized to disrupt local testicular function and reduce s***m output — effects that were reversible when the fabric was removed.
🧬 S***m Count & Semen Quality Differences
Observational research has linked looser, breathable underwear (like cotton boxers) with higher s***m concentrations, total s***m counts, and motility compared with tighter or synthetic garments.
Practical Tips to Support Fertility
If you’re planning to conceive or just want to make a low-cost, low-risk tweak to your routine, consider:
✔ Choosing breathable, natural fabrics like cotton, linen or bamboo
✔ Avoiding tight, synthetic underwear that may increase local heat or moisture
✔ Focusing on other proven fertility habits — healthy diet, regular exercise, and avoiding smoking or excessive heat exposure
📌 Bottom Line: Everyday choices — even something as simple as underwear — are part of a broader picture of reproductive health. While polyester alone is unlikely to make someone infertile, choosing cooler, more breathable fabrics may help support optimal fertility.