Going without underwear changes how your skin interacts with moisture, heat, and the fabrics of your outer clothing, and the effects differ quite a bit depending on your anatomy, your activity level, and what you’re wearing over bare skin. For people with vulvas, skipping underwear can reduce trapped moisture and may lower the risk of certain infections. For people with penises, looser conditions around the groin may modestly benefit sperm production. But the story isn’t as simple as “underwear bad, commando good,” because underwear also serves as a barrier against friction, absorbs sweat, and catches bodily fluids that would otherwise end up in harder-to-clean outerwear.
Moisture, Ventilation, and Vulvovaginal Health
The most commonly cited benefit of going without underwear applies to people with vulvas. The vulvar skin is thinner and more sensitive than skin on most other parts of the body, and it sits in a warm, enclosed environment where moisture can accumulate quickly. Adding a layer of underwear, especially one made from synthetic fabric that doesn’t breathe well, can trap heat and moisture against the skin. That warm, damp environment is exactly what yeast and other fungi thrive in. Going commando, or at least sleeping without underwear, reduces this trapped moisture and allows more airflow to the area.
Gynecologists often suggest that patients prone to recurrent yeast infections try sleeping without underwear or switching to loose cotton styles. The logic is straightforward: less moisture means a less hospitable environment for Candida overgrowth. This doesn’t mean underwear causes yeast infections on its own. Yeast infections have many triggers, from antibiotics to hormonal shifts to high blood sugar. But chronic moisture trapping is a modifiable factor, and going without underwear is one way to address it.
Bacterial vaginosis, the most common vaginal infection in reproductive-age women, is influenced by shifts in the vaginal microbiome rather than by external moisture alone. There’s no strong evidence that underwear choice directly causes BV. Still, anything that keeps the vulvar area drier and reduces irritation from fabric dyes, detergent residues, or synthetic fibers may help maintain the skin’s natural barrier function.
What Changes for Men
The testes hang outside the body for a reason: sperm production works best a few degrees below core body temperature. Tight underwear pushes the testes closer to the body, raising scrotal temperature. An early pilot study examining this relationship found that semen parameters, including sperm density and total motile sperm count, gradually decreased when men wore tight underwear and gradually increased during periods of wearing loose-fitting styles. Although preliminary, the results supported the idea that underwear fit can influence sperm production.1PubMed. Fit of underwear and male spermatogenesis: a pilot investigation
Going without underwear entirely is the logical extension of wearing loose boxers: it removes the extra insulating layer and lets the scrotum regulate its own temperature more freely. For men who are actively trying to conceive and have borderline semen analysis results, this is one low-effort change worth trying. For men not concerned about fertility, the practical difference is smaller. Scrotal temperature matters most during sustained periods of heat exposure, so occasional tight underwear isn’t going to cause lasting harm.
There’s also the question of support. Some men find that going commando during everyday activities feels fine, but during exercise, the lack of support leads to discomfort, chafing, or that unpleasant sensation of everything moving around. Athletic supporters and compression shorts exist for a reason, and skipping them during running or cycling can lead to skin irritation from repeated friction against outer fabric seams.
Chafing and Skin Irritation
One of underwear’s most underappreciated jobs is acting as a barrier between your skin and your outer clothing. Jeans, trousers, skirts, and shorts often have seams, zippers, and rougher fabrics right where they contact the groin, inner thighs, and buttocks. Without a smooth layer of underwear in between, these can rub directly against sensitive skin.
Chafing is most likely in warm weather, during exercise, or when wearing stiff fabrics like raw denim. The inner thighs are particularly vulnerable because they rub against each other during walking and running. Underwear with a smooth fabric and a snug (but not tight) fit reduces this friction. Going commando in soft joggers or a flowy skirt is a very different experience from going commando in tight jeans. The outer garment matters enormously.
For people who do go without underwear regularly, applying an anti-chafe balm or body powder to friction-prone areas can help. Choosing outer clothing with flat-felled seams (where the seam is folded flat rather than raised) also reduces irritation. But if you’re prone to inner-thigh chafing, underwear is often the simpler fix.
Sweat, Odor, and Hygiene
The groin is one of the body’s highest-concentration areas for apocrine sweat glands, which produce the thicker, protein-rich sweat that skin bacteria break down into body odor. Whether you wear underwear or not, you’re going to sweat there. The question is where that sweat ends up.
Underwear absorbs a large share of this sweat before it reaches your pants or skirt. When you go commando, that sweat soaks directly into your outer garment. The practical consequence: you may need to wash your pants more frequently, and some fabrics (particularly synthetics) hold odor-causing bacteria more stubbornly than cotton underwear does. Research on sweat accumulation in layered clothing systems has shown that how moisture distributes across fabric layers depends on the fiber type and construction of each layer. During heavy sweating, inner layers absorb a significant portion of moisture that would otherwise migrate outward, and this distribution affects both comfort during activity and the feeling of dampness during rest.2Taylor & Francis Online (Ergonomics). The impact of activity level on sweat accumulation and thermal comfort using different underwear
Vaginal discharge is another consideration for people with vulvas. Normal physiological discharge is a healthy part of how the vagina cleans itself, but it has to go somewhere. With underwear, it’s absorbed by the fabric and contained. Without underwear, it transfers directly to your outer clothing, which can leave visible marks on lighter-colored pants and may create an uncomfortable wet sensation depending on the fabric. Panty liners are one workaround for people who prefer going commando but want to manage discharge, though liners themselves can trap moisture if not changed regularly.
From a pure bacterial standpoint, underwear doesn’t keep the groin sterile. The area has a rich microbiome regardless. But underwear does provide a changeable, washable layer that’s easier to keep clean than most outer garments. If you go commando and don’t wash your jeans frequently, you’re letting sweat and bacteria build up in a garment that sits against your skin day after day.
Going Commando During Exercise
Many athletic garments, from running shorts to cycling bibs to yoga pants, are designed to be worn without underwear. They have built-in liners, moisture-wicking fabrics, and flat seams that minimize chafing. Wearing cotton underwear beneath these can actually be counterproductive, because cotton absorbs sweat and holds it against your skin rather than wicking it away. That trapped moisture increases friction and can lead to more chafing, not less.
If your workout clothes have a built-in brief or liner, the garment is doing the job underwear would do. Adding underwear on top of that creates bunching and extra seams. For activities like cycling, where you’re seated on a narrow saddle for extended periods, chamois-padded shorts are specifically designed for direct skin contact, and wearing underwear beneath them defeats the purpose of the chamois pad’s moisture management.
High-intensity exercise produces heavy sweating in the groin, and the accumulation of that sweat in clothing layers affects both thermal comfort and skin health. The fiber type of whatever is touching your skin matters more than whether it’s technically called “underwear” or “shorts.” A synthetic moisture-wicking short worn without underwear will generally keep you drier than a cotton underwear layer beneath a synthetic short, because the cotton holds the moisture at the skin surface.
Sleeping Without Underwear
Nighttime is when going commando gets the most straightforward endorsement from dermatologists and gynecologists. During sleep, you’re not walking, sweating heavily, or dealing with friction from seams and zippers. The groin area gets eight or so hours in a warm, enclosed environment regardless, and removing one layer of fabric improves airflow without introducing any of the downsides that come up during the day.
For people prone to vulvar irritation, jock itch, or heat rash in the groin folds, sleeping without underwear is often one of the first recommendations. Wearing loose pajama bottoms or nothing below the waist lets moisture evaporate more freely. If you sleep in underwear, choose cotton or another breathable fabric and avoid anything tight-fitting.
The case for sleeping commando is strong enough that it’s worth treating as a separate question from going commando during the day. The daytime tradeoffs around chafing, discharge management, and clothing protection don’t apply at night. If you’re going to try going without underwear, bedtime is the lowest-risk place to start.
Contact Dermatitis and Fabric Sensitivity
Some people develop irritation not from the absence of underwear but from the underwear itself. Contact dermatitis in the groin can be triggered by elastic waistbands, synthetic fabrics, fabric dyes (especially dark colors), or residues from laundry detergent and fabric softener. The skin in the groin is more permeable than skin elsewhere, which makes it more susceptible to chemical irritants.
For these people, going commando can actually resolve chronic itching, redness, or rash that they may have attributed to other causes. If you’ve been dealing with persistent groin irritation and have ruled out infections, it’s worth considering whether your underwear is the culprit. Switching to undyed, unscented cotton underwear is the usual first step, but eliminating the layer entirely is another option, especially if the irritation is along the waistband or leg elastic lines.
On the flip side, going commando in rough or heavily dyed outer garments can introduce the same problem from a different source. Denim dyes, polyester blends, and stiff seam allowances can irritate the skin just as effectively as the wrong underwear. The goal isn’t necessarily to remove a layer; it’s to ensure that whatever touches your groin skin is soft, breathable, and free of chemical irritants.
Skin Integrity and Older Adults
For older adults, skin in the groin area faces additional challenges. Aging skin is thinner, less elastic, and slower to heal. People dealing with urinary or fecal incontinence have an added concern: prolonged skin exposure to urine or stool can cause incontinence-associated dermatitis, an irritant skin condition marked by redness, pain, and breakdown of the skin surface that frequently leads to secondary infection.3PubMed Central. Incontinence-Associated Dermatitis in Older Adults: A Critical Review of Risk Factors, Prevention and Management
In this population, the underwear question takes on a different dimension. High-absorbency incontinence products function as specialized underwear designed to pull moisture away from the skin and contain it. Going without any protective garment when leakage is an issue leaves urine or stool in direct contact with already-vulnerable skin for longer periods, accelerating breakdown. For older adults managing incontinence, the right absorbent product, changed regularly, is protective in a way that going commando is not.
For older adults without incontinence concerns, the same general principles apply as for younger people, but with even more emphasis on avoiding friction and maintaining skin integrity. Thin, fragile skin tears more easily from rough seams, and heals more slowly once damaged. Soft, well-fitting underwear can protect against abrasion from outer clothing, while overly tight or elastic-heavy styles can create pressure injuries in skin that’s lost its resilience.
What About Infections You Pick Up From Outside?
A persistent worry for some people is whether going commando exposes the genitals to more environmental bacteria, especially when sitting on public surfaces. In practical terms, the thin fabric of most underwear is not a meaningful microbial barrier. Bacteria, fungi, and viruses don’t line up at the edge of your underwear and politely stop. If a pathogen is on a surface and you sit on it in thin cotton briefs, the fabric isn’t providing hospital-grade protection.
That said, underwear does provide a physical barrier against direct skin contact with surfaces. Sitting on a gym bench, a shared chair, or a public toilet seat without underwear means your bare skin touches whatever is there. The actual risk of picking up a serious infection this way is quite low for intact skin. Most sexually transmitted infections require mucous membrane contact or breaks in the skin. Fungal infections like jock itch are more about your own skin environment (warm, moist, dark) than about what you sat on. The bigger everyday risk from gym surfaces is skin-to-surface contact with common fungi and bacteria, and underwear offers a thin but real layer of separation.
For people who use public pools, hot tubs, or saunas, the calculus shifts. These environments have their own hygiene concerns related to waterborne pathogens, and going without a swimsuit bottom or underwear in communal water is both a social norm violation and a genuine hygiene issue. But in normal daily life, the infection risk from going commando is minimal as long as you’re maintaining basic hygiene and washing whatever garments do touch your skin.
Practical Tips for Going Commando Comfortably
If you want to try going without underwear, a few choices make the experience better:
- Fabric matters most: Soft, breathable outer garments (cotton, linen, bamboo blends) cause far less irritation than stiff synthetics or raw denim worn against bare skin.
- Seam placement: Check where the inseam and crotch seams of your pants fall. Flat or covered seams reduce chafing; raised seams with exposed stitching can dig into sensitive skin.
- Wash your pants more often: Without an underwear layer absorbing sweat and discharge, outer garments accumulate body oils and bacteria faster. What you could wear three times between washes with underwear may need washing after one wear without.
- Anti-chafe products: A light application of body glide or cornstarch-based powder to the inner thighs and groin folds prevents friction-related irritation, especially in warm weather.
- Start at night: Sleeping commando gives you the ventilation benefits without the friction, discharge, and sweat challenges of daytime activity. It’s the easiest entry point.
Who Should Probably Keep Wearing Underwear
Going commando isn’t for everyone, and some situations make underwear clearly the better choice. People managing urinary or fecal incontinence need absorbent products to protect their skin. People with active skin infections in the groin, such as cellulitis or widespread fungal rashes, benefit from a clean cotton barrier that keeps medications in place and prevents the infected area from rubbing against rougher outer fabrics. People recovering from groin surgery typically need the wound support and protection that snug, clean underwear provides.
During menstruation, underwear serves as a backup for pads, tampons, menstrual cups, or period underwear. Going commando during a period isn’t impossible with a cup or disc, but most people find that having a fabric safety net reduces anxiety about leaks. Period underwear, which is designed with built-in absorbent layers, is a hybrid option that provides the benefits of both coverage and breathability.
Athletes in high-friction sports, particularly distance runners and cyclists, generally do better with a purpose-built liner or compression layer than with nothing at all. As noted earlier, this doesn’t mean traditional cotton underwear; it means sport-specific garments designed for skin contact. The worst option for exercise is usually cotton underwear under synthetic shorts, while the best is either built-in liners or well-designed compression wear. Going fully commando in loose running shorts without a liner tends to lead to chafing on longer efforts.