Whenever you’re choosing underwear, your first priority may be how it looks on you. For many guys, aesthetics are crucial in terms of their underwear of choice. Comfort obviously matters too. If your underwear is too loose or tight, then it’s not going to provide the comfort you need. Plus, you run the risk of them falling down when you’d rather they didn’t (too loose) or revealing a bit too much (too tight). Underwear needs to provide the right level of comfort.

Most men think about aesthetics and comfort when choosing underwear. What they don’t usually think about, though, is how the style of underwear can have an impact on their health. Indeed, research has shown that choosing between boxers and briefs can affect your sperm count.

How Tightness of Underwear Can Affect Sperm Health

A 2018 study published in the journal Human Reproduction found that men who wear boxers have a higher sperm count than those who wear briefs. The researchers, from Harvard University, discovered that men who sport boxers have a 25% higher sperm concentration, 17% higher sperm count, and 33% more swimming sperm in a single ejaculate than men who wore briefs. These were the results after adjustments were made for age, body mass index (BMI), physical activity, smoking, and whether or not participants had frequent hot baths. These adjustments help to ensure accurate data, although it’s entirely possible that other factors could influence these differences in sperm count.

The study suggests that wearing tight underwear can affect sperm production. However, the study didn’t find out what would happen to your sperm count by switching styles of underwear, nor did it make any conclusions about whether a lower sperm count would translate into a lower likelihood of conceiving a child.

The scientists behind the study highlighted that the men who wore tighter underwear had higher levels of a reproductive hormone in the blood, known as the follicle-stimulating hormone (FSH). It’s a hormone that stimulates sperm production. So, researchers suggest that men who wear tighter underwear have higher levels of FSH as a way to compensate for lower sperm production.

Men who wear tight underwear still have a sperm count within the normal range, so fertility shouldn’t really be affected. Although, Jorge Chavarro – one of the authors of the study – did state:

“The men who may benefit most from paying attention to what type of underwear they’re wearing are men who are already having problems with fertility.”

The Link Between Heat and Sperm Count

The reason the researchers adjusted for factors like frequent hot baths is that heat can affect sperm count. For example, previous research has shown that when you go into a sauna, you can end up with a lower sperm count. Applying these findings to the 2018 study on boxers and briefs, lower sperm production may result from the fact that tighter underwear holds the testicles closer to the body, raising their temperature.

It’s not just the style of underwear that can raise testicular temperature; underwear’s fabric can also have an effect. Generally speaking, the more natural the material, the better the breathability. This means that fabric such as cotton is less likely to raise the temperature of the testicles than polyesters, which can trap heat.

Should You Switch From Briefs to Boxers?

As already mentioned, unless you have fertility issues, there’s no clear evidence that wearing briefs will thwart your ability to have kids. According to Dr. Michael Eisenberg, the director of male reproductive medicine and surgery at Stanford University School of Medicine, “I generally counsel men that they can choose the type of underwear that is most comfortable. But if they do feel warm or constricted, then another type may make sense.”

Now, you may think that boxers just don’t look as good as briefs. Fortunately, though, you don’t have to sacrifice aesthetics for comfort or sperm health. There are a huge variety of briefs. It’s always worth finding a particular brand, fitting, and fabric that gives you maximum comfort, room, and breathability. Also, don’t forget to take your jeans into consideration too, if you’re worried about your sperm health. Jeans that are too tight can lead to the same issues caused by tight underwear.