Body odor happens when bacteria on your skin break down the compounds in sweat, producing that familiar unpleasant smell. Getting rid of it comes down to three things: reducing the sweat bacteria feed on, killing or limiting those bacteria, and making lifestyle changes that lower the chemical load your body pushes out through your pores. Most people can eliminate noticeable body odor with a few targeted adjustments.
Why Sweat Smells
Your body has two types of sweat glands. Eccrine glands cover nearly your entire body and produce the watery sweat you notice during exercise or heat. Apocrine glands are concentrated in your underarms, groin, and around the nipples, and they secrete a thicker fluid into hair follicles. Neither type of sweat actually smells on its own. The odor develops when bacteria and yeasts that naturally live on your skin decompose that sweat, particularly the protein-rich secretions from apocrine glands.
This is why your underarms are the primary source of body odor, not your forehead or shins. The combination of apocrine glands, warm enclosed skin folds, and hair that traps moisture creates ideal conditions for bacterial growth.
Daily Hygiene That Actually Works
Showering once or twice daily with antibacterial soap targets the root cause: the bacteria doing the decomposition. Focus on areas with apocrine glands. Letting soap sit on your underarms for 30 seconds before rinsing gives it time to work, rather than a quick pass with a washcloth. Drying thoroughly matters too, since bacteria thrive in moisture.
Shaving or trimming underarm hair reduces the surface area where bacteria can colonize and where sweat pools. It also helps antiperspirants make better contact with your skin. If you notice odor breaking through by midday, carrying antibacterial wipes for a quick underarm refresh can bridge the gap.
Choosing the Right Antiperspirant
Deodorant and antiperspirant do different jobs. Deodorant masks or neutralizes odor. Antiperspirant contains aluminum salts that temporarily plug sweat ducts, reducing the moisture bacteria need. For body odor, you typically want both functions, and most products combine them.
Regular antiperspirants contain around 10% active aluminum compounds. Clinical-strength versions bump that to about 20%, which makes a real difference for people who find standard products insufficient. For the best results, apply clinical-strength antiperspirant to dry skin at bedtime, when sweat production is lowest and the aluminum salts can form a more effective barrier. Wash it off in the morning and apply your regular deodorant for the day.
If over-the-counter options aren’t cutting it, prescription antiperspirants containing aluminum chloride hexahydrate at concentrations of 10% to 15% are available. These are significantly more effective but can irritate skin if not used carefully. The typical approach is to apply nightly until sweating decreases, then scale back to once or twice a week to maintain the effect.
What You Wear Matters
Polyester and other synthetic fabrics trap significantly more odor-causing bacteria than cotton. Researchers found that a specific type of bacteria called Micrococci thrives on polyester but not cotton. These microbes accumulate in tiny sweat pools between synthetic fibers, creating the perfect breeding ground. This is why a polyester workout shirt can smell terrible after one use while a cotton tee stays relatively fresh.
Choose natural fibers like cotton, linen, or merino wool when odor is a concern, especially for layers closest to your skin. If you prefer synthetic athletic wear, look for fabrics treated with antimicrobial finishes, and wash them promptly after wearing. Wearing a fresh shirt daily (or changing midday if needed) prevents bacterial buildup from compounding over time.
Foods That Change How You Smell
Your body eliminates certain chemical byproducts through sweat, and some foods produce more odor-causing compounds than others. Cruciferous vegetables like broccoli, cabbage, cauliflower, and Brussels sprouts contain sulfur compounds that can intensify body odor. Eggs, liver, and seafood are high in a compound called trimethylamine, which your body normally breaks down with a specific liver enzyme. When that breakdown is efficient, no problem. When it’s not, the chemical can seep into your sweat, breath, and saliva with a strong fishy smell.
Garlic, onions, and strong spices like cumin and curry are well-known contributors. Alcohol also changes your scent as your body metabolizes it. You don’t necessarily need to eliminate these foods entirely, but if you’re struggling with persistent odor, cutting back for a couple of weeks can help you identify whether diet is a factor.
When Standard Fixes Aren’t Enough
Some people produce more sweat or have a bacterial profile on their skin that generates stronger odor despite good hygiene. If clinical-strength antiperspirants, daily washing, and fabric choices haven’t solved the problem, medical options exist.
Botulinum toxin injections into the underarms block the nerve signals that trigger sweat glands. In a study of 62 adolescent patients, 82% rated results as good or very good. The effect typically lasts about a month per treatment, and some people need multiple injections. It’s most commonly used for excessive sweating, but the reduction in sweat also reduces odor.
Microwave-based therapy is a newer option that permanently destroys sweat glands in the underarms. Patient satisfaction is high, and the results are lasting since destroyed glands don’t regenerate. Prescription wipes containing glycopyrronium tosylate can also reduce sweating on the hands, feet, and underarms, though they may cause dry mouth as a side effect.
Nerve-blocking oral medications are another route, reducing sweat production body-wide. Side effects can include dry mouth, blurred vision, and bladder issues, so they’re generally reserved for cases where localized treatments haven’t worked.
Medical Conditions That Cause Unusual Odor
Persistent body odor that doesn’t respond to any of these measures can occasionally signal an underlying condition. Trimethylaminuria, sometimes called fish odor syndrome, is a genetic condition where the liver enzyme that breaks down trimethylamine doesn’t function properly. The result is a strong fishy smell from sweat, breath, and urine. It’s rare but underdiagnosed, and managing it involves avoiding high-trimethylamine foods like fish, eggs, beans, and soy products. Activated charcoal supplements can help bind the compound and move it out of your system.
Liver and kidney disease can also alter body odor, as can uncontrolled diabetes, which produces a fruity or acetone-like smell when the body burns fat for fuel instead of sugar. Hormonal shifts during puberty, menopause, or thyroid disorders can increase apocrine gland activity and change odor patterns. If your body odor has changed suddenly or dramatically, or if it has a distinct unusual quality like sweetness or fishiness, that’s worth investigating with a doctor, as the odor itself may be a useful diagnostic clue.