A noticeable smell from your penis is almost always caused by one of a few common, fixable issues: trapped sweat, a buildup of dead skin cells and oils under the foreskin, or an overgrowth of bacteria or yeast. In most cases, better cleaning habits solve the problem within days. Sometimes, though, the smell signals an infection or skin condition that needs treatment.
Sweat and Bacteria Are the Most Common Cause
Your groin is packed with apocrine glands, the same type of sweat gland responsible for underarm odor. These glands release a small amount of oily fluid that is actually odorless when it first hits your skin. The smell develops when bacteria on the surface break that fluid down into ammonia and short-chain fatty acids. The warm, enclosed environment of the groin accelerates this process, especially if you wear tight clothing or synthetic fabrics that trap moisture.
This type of odor tends to be strongest after exercise or a long day, and it washes away easily. If the smell disappears after a shower and returns only with sweating, bacteria acting on sweat is almost certainly what you’re dealing with.
Smegma Buildup
If you’re uncircumcised, the most likely explanation for a persistent smell is smegma. This is a whitish-yellow, cheese-like substance that collects under the foreskin. It’s made of shed skin cells, natural oils (about 27% fat and 13% protein), and a small amount of mucus. It forms naturally as living cells on the inner surface of the foreskin grow outward, undergo fatty breakdown, and slough off.
Smegma itself isn’t harmful in small amounts, but when it accumulates, it develops a distinct slimy odor and becomes a breeding ground for bacteria. It can form whether or not your foreskin fully retracts, and even people who have been circumcised can get minor buildup in skin folds. The fix is straightforward: gently pull back the foreskin each day in the shower and rinse underneath with water. A mild, unscented soap is fine, but too much soap or scrubbing can irritate the delicate skin and actually make things worse by disrupting the natural balance of bacteria.
Yeast Infections
Yeast infections aren’t just a concern for women. A penile yeast infection (candidiasis) produces a foul-smelling discharge that’s thick, white, and often compared to cottage cheese. Other signs include redness in patches around the groin, burning or itching around the head of the penis and under the foreskin, difficulty pulling the foreskin back, and sometimes shiny sores or blisters.
The warm, moist environment under the foreskin makes yeast overgrowth more likely, particularly after a course of antibiotics, during periods of high blood sugar, or if the area stays damp for long stretches. Over-the-counter antifungal creams typically clear it up, but if symptoms don’t improve within a week or keep coming back, you may need a prescription-strength treatment.
Balanitis
Balanitis is inflammation of the head of the penis, and it’s one of the more common reasons for a persistent bad smell that doesn’t resolve with normal washing. The hallmark signs are redness, swelling, pain at the tip, and a white, cheesy discharge with a noticeable odor. It can be triggered by a yeast infection, a bacterial overgrowth from poor hygiene, an allergic reaction to soaps or condoms, or skin conditions like eczema or psoriasis. People with diabetes have a higher risk because elevated blood sugar encourages microbial growth.
Treatment depends on the cause. Bacterial balanitis typically requires a short course of antibiotics, while yeast-driven balanitis responds to antifungal medication. If a soap or chemical is triggering it, switching to water-only washing under the foreskin often resolves the problem.
Sexually Transmitted Infections
Some STIs cause penile discharge that carries an odor. Trichomoniasis can produce irritation inside the penis, burning after urination or ejaculation, and discharge. Gonorrhea and chlamydia can also cause unusual discharge and are among the recognized triggers for balanitis. Many STIs in men produce mild or no symptoms at all, so a new smell combined with any discharge, burning, or sores is worth getting tested for, especially after unprotected sex.
How to Clean Properly
Daily washing is the single most effective way to prevent penile odor. If you’re uncircumcised, gently pull back the foreskin and rinse the entire area underneath, including the groove behind the head of the penis. Water alone is sufficient. If you prefer soap, use a small amount of something mild and fragrance-free. Heavily scented body washes, antibacterial soaps, and vigorous scrubbing can strip away protective bacteria and irritate the skin, which sometimes leads to more odor rather than less.
After washing, dry the area thoroughly before putting on underwear. Moisture left behind feeds the same bacteria you just washed off. Breathable cotton underwear helps keep things dry throughout the day, while synthetic fabrics tend to trap heat and sweat.
When the Smell Signals Something Serious
If the odor persists after consistent daily washing, or if it comes with sores, discharge, redness, swelling, or pain, something beyond normal hygiene is going on. Rarely, a sudden putrid smell from the genitals accompanied by fever, chills, confusion, or nausea can indicate Fournier’s gangrene, a life-threatening infection of the soft tissue that requires emergency treatment. This is uncommon but progresses fast, so those symptoms together warrant an immediate trip to the emergency room.
For less urgent but persistent odor, a healthcare provider can often diagnose the cause with a visual exam and a swab of any discharge. Most conditions that cause penile odor resolve quickly once identified and treated properly.