Can switching underwear material actually improve fertility?

Clinical evidence supports that changing underwear material from synthetic to natural fibers can improve male fertility markers. In the Shafik study, men who became azoospermic (zero sperm count) while wearing polyester underwear saw complete recovery of sperm production within months of switching to cotton. This is one of the clearest demonstrations in reproductive medicine that a simple lifestyle change can reverse a severe fertility impairment.

The improvement is attributed to removing two harmful exposures simultaneously: the electrostatic disruption caused by polyester friction and the thermal stress caused by synthetic fabrics trapping heat against the scrotum. Natural fibers like organic cotton and merino wool allow better air circulation, wick moisture more effectively, and do not generate the static charges that interfere with testicular function. The cumulative effect is a cooler, more electrically neutral environment that supports normal spermatogenesis.

For couples experiencing unexplained infertility, switching to natural-fiber underwear is one of the lowest-cost, lowest-risk interventions available. It requires no medical procedure, has no side effects, and the evidence of benefit is relatively strong. ONDU features everyday essentials from Pact and Organic Basics made with GOTS-certified organic cotton, providing easy access to fertility-friendly undergarments.