Boxers or briefs? Study finds boxers boost sperm count

For men who like wearing briefs and want to start a family, it may be time to switch to boxers.  A new study published in the Journal of Human Reproduction finds that tighter fitting underwear like briefs, inhibit the production of sperm which could explain why some couples experience male infertility.

The study spanned over 17 years – from 2000 to 2017 – and is the largest and most comprehensive to date. Researchers collected semen from 656 men and blood samples from 304 men between the ages of 32-39. All of the men were seeking fertility treatment.  What was discovered was that men who wore tight-fitting underwear (briefs) had 14 percent higher levels of Follicle Stimulating Hormone (FSH) compared to men who wore looser-fitting boxers. FSH is an endocrine hormone released by the pituitary gland into the blood to regulate sperm production. 

Also found was the that men who wore boxers had a 25 percent higher sperm count concentration and 17 percent higher sperm counts than the men who wore briefs. In addition, men who wear boxers also had greater sperm motility meaning their sperm were better able to move which increases the likelihood of successfully navigating through a woman’s reproductive system and finding the egg to fertilize. The relationship between semen quality and what style of underwear men wear has been under scrutiny for decades.  It has been known from past studies that higher temperatures in briefs affect sperm but this new study is the largest of its kind to analyze multiple styles of underwear – boxers, briefs, jockeys, and others.

A significant difference and distinguishing feature of this study from past studies is that it is the first to specifically evaluate reproductive hormones and how they are affected by the kind of underwear a man wears.  What this study has shown is that underwear matters in terms of testicular function and reproductive hormones.

The hope of the findings discovered from this study is that it can provide more clarity of why some couples struggle to conceive and that it looks like underwear style does matter in terms of testicular function.

So, should all men be wearing boxers instead of briefs? The answer to this is no. Not all men are actively trying to conceive a baby and most men have no idea what their sperm count is. Depending on a man’s baseline sperm count, the 25 percent decrease in sperm count in men who wear briefs, may or may not be a significant problem for each man. It also was pointed out that even if a man switches from wearing briefs to boxers, changing the style of underwear will not have an immediate effect on sperm count. It takes the spermatogenic cycle about 90 days to fully form a mature sperm so anything that could potentially affect sperm production would take about 3 months to have an effect. But, at the same time, for couples wanting to improve their chances of conceiving, a trip to a man’s clothing store to buy boxers may help.