Genital odor is almost always caused by one of two things: bacteria breaking down sweat on the surrounding skin, or a shift in the natural bacterial balance inside the vagina. Both are common, and both are manageable once you understand what’s driving the smell. In most cases, a few changes to your daily hygiene routine are enough to make a noticeable difference.
Why There’s a Smell in the First Place
The groin is packed with apocrine sweat glands, the same type found in your armpits. These glands sit inside hair follicles and produce a thicker sweat that contains fats and proteins. The sweat itself is mostly odorless, but when bacteria on your skin break it down, the byproducts smell. The combination of warmth, moisture, and limited airflow makes the groin one of the most odor-prone areas on the body.
For people with vaginas, there’s a second layer. A healthy vagina maintains a pH between 3.8 and 4.5, slightly acidic, which keeps protective bacteria thriving and blocks harmful germs. When that pH shifts upward (becomes less acidic), odor-causing bacteria can take over. The result is often a fishy smell produced by specific chemical compounds called amines. These same compounds, particularly trimethylamine, putrescine, and cadaverine, are what give rotting fish its smell, so even a mild imbalance can produce a strong odor.
For people with penises, odor typically comes from smegma, a buildup of oils, dead skin cells, and sweat that collects under the foreskin or around skin folds. Smegma itself isn’t bacteria, but it creates a perfect environment for bacteria to multiply, and that bacterial overgrowth is what smells.
Daily Hygiene That Actually Helps
The most effective approach is also the simplest: warm water, applied daily. The University of Iowa Health Care guidelines recommend not using soap directly on vulvar skin. Soap, even mild or “pH-balanced” varieties, can strip the natural oils and disrupt the bacterial ecosystem that keeps odor in check. Warm water alone is enough to rinse away sweat, dead skin, and surface bacteria from the external genitals.
If you feel you need more than water, use an unscented, gentle cleanser only on the outer skin (the vulva, groin creases, or shaft) and keep it away from internal tissue. Never douche or use internal washes. Douching pushes bacteria deeper, disrupts vaginal pH, and consistently makes odor worse over time, not better.
For uncircumcised people, gently pulling back the foreskin and rinsing underneath with warm water each day prevents smegma from accumulating. This single step eliminates the most common cause of penile odor.
What You Wear Matters More Than You Think
Cotton underwear wicks away moisture and lets air circulate, which starves the bacteria that produce odor. Synthetic fabrics like nylon and polyester trap heat and sweat against the skin, creating the damp conditions bacteria and yeast love. Even underwear marketed as having a “cotton crotch panel” doesn’t offer full protection, because the surrounding synthetic fabric still limits breathability.
A few other clothing changes that help: avoid sitting in wet swimsuits or sweaty workout clothes for extended periods. Change underwear after heavy sweating. Choose looser-fitting pants or shorts when possible, especially in warm weather. Tight clothing presses fabric against skin folds and reduces airflow, which concentrates odor.
When the Smell Points to an Infection
A persistent fishy odor, especially one that gets stronger after sex, is the hallmark of bacterial vaginosis (BV). BV happens when the protective bacteria in the vagina lose ground to other species, particularly one called Gardnerella. The overgrowth produces high levels of trimethylamine and other amines that cause that distinct fishy smell. BV is the most common vaginal infection in people of reproductive age, and it won’t resolve on its own in most cases. It requires a short course of treatment from a healthcare provider.
Other infections that can change genital odor include yeast infections (which tend to produce a bread-like or beer-like smell along with thick discharge) and trichomoniasis (a sexually transmitted infection that can cause a strong, unpleasant odor with yellow-green discharge). A forgotten tampon or other retained object can also produce a sudden, intense smell that resolves once it’s removed.
If your odor is new, significantly stronger than usual, or accompanied by unusual discharge, itching, or burning, that pattern points toward an infection rather than a hygiene issue.
Things That Shift Vaginal pH
Understanding what disrupts vaginal pH helps you avoid triggering odor in the first place. Several everyday factors push the pH upward and weaken the protective acid environment:
- Semen. It has a pH around 7.2 to 8.0, which temporarily raises vaginal pH after unprotected sex. This is why some people notice a stronger smell the day after sex.
- Menstrual blood. Blood has a neutral pH, so periods can briefly shift the balance. Changing pads and tampons frequently helps minimize this effect.
- Scented products. Vaginal deodorants, scented pads, perfumed body wash, and bubble baths introduce chemicals that irritate tissue and alter bacterial balance.
- Antibiotics. They kill protective bacteria along with the targeted infection, which can trigger BV or yeast overgrowth as a side effect.
After any of these exposures, the vagina typically rebalances itself within a day or two. Persistent changes lasting more than a week suggest the balance hasn’t recovered on its own.
Boric Acid Suppositories
Boric acid vaginal suppositories are sometimes recommended for recurrent BV or yeast infections that don’t respond well to standard treatment. They work by restoring the acidic pH environment. They’re used at bedtime, inserted vaginally, and should never be taken by mouth, as boric acid is toxic if swallowed. During treatment, condoms, diaphragms, and spermicides may not work properly, and tampons should be avoided. These are best used under the guidance of a healthcare provider rather than as a first-line approach to odor.
Lifestyle Factors That Reduce Odor
Staying hydrated dilutes the concentration of waste products in your sweat, which can soften body odor overall. Some people notice that certain foods, particularly garlic, onions, asparagus, and heavily spiced meals, temporarily intensify genital odor. The effect varies from person to person and typically passes within 24 to 48 hours.
Sleeping without underwear or in loose shorts gives the area hours of airflow overnight, which helps keep moisture levels low. Trimming (not necessarily removing) pubic hair can also reduce the surface area where sweat and bacteria interact, though this is a personal choice and not medically necessary.
Probiotics containing Lactobacillus strains, the same bacteria that dominate a healthy vaginal environment, are sometimes used to support vaginal balance. The evidence is mixed on whether oral probiotics reliably change vaginal flora, but they’re generally safe to try alongside other hygiene measures.
What’s Normal and What Isn’t
Every body has a natural scent, and genitals are no exception. A mild, musky smell is completely normal and changes slightly throughout the menstrual cycle, after exercise, or depending on what you’ve eaten. The goal isn’t to eliminate all scent, which isn’t possible or healthy. The goal is to avoid the strong, persistent, or unusual odors that signal something is off. If warm water, breathable fabrics, and avoiding irritating products don’t resolve the smell within a week or two, that’s a sign the cause may be an infection or imbalance that needs professional attention.