Smegma, commonly called “dick cheese,” is a buildup of dead skin cells, natural oils, and sweat that collects under the foreskin. It forms through the same biological processes that happen everywhere on your body, but the warm, enclosed space beneath the foreskin gives these substances a place to accumulate instead of being wiped or washed away.
What Smegma Is Made Of
Your skin constantly sheds dead cells and produces oil through tiny glands called sebaceous glands. These glands exist all over your body, but the genital area has a particularly high concentration of them. Sweat glands add moisture to the mix. On exposed skin, these substances fall away or get absorbed into clothing. Under the foreskin, they have nowhere to go.
The result is a soft, whitish substance that can look and feel like cottage cheese or a paste. When it first forms, smegma is typically thin and moist. If it sits for days without being washed away, it thickens, dries out, and develops a stronger smell. That odor comes from bacteria on the skin breaking down the oils and dead cells, producing waste compounds in the process, much like how bacteria cause body odor in your armpits.
Why the Foreskin Creates the Perfect Environment
The foreskin covers the head of the penis and creates a warm, dark, slightly moist pocket. This space traps everything the skin produces: oils, shed cells, sweat, and small amounts of urine residue. Without regular cleaning, these materials layer on top of each other. The warmth also encourages bacterial growth, which speeds up the breakdown of those materials and intensifies the smell.
Circumcised men can still develop smegma in the skin folds around the base of the head, but it’s far less common because the area is exposed to air and gets cleaned more naturally through everyday friction with clothing.
Smegma in Children Is Normal
In uncircumcised boys, the foreskin is firmly attached to the head of the penis at birth and gradually separates over the first several years of life. During this process, you may notice white, cheesy material appearing between the layers of skin, or small “white pearls” forming under the fused skin. This is smegma, and it actually plays a role in helping the foreskin detach from the head of the penis. It is not a sign of infection. The foreskin may not fully retract until age five or six, and this is completely normal. Parents should not force the foreskin back to clean underneath it before it separates on its own.
What Happens If It Builds Up
Smegma itself is harmless. It’s a natural byproduct of skin biology, not a sign of disease. But when it accumulates over time, it can cause problems. The buildup irritates the sensitive skin of the head of the penis and the inner foreskin, leading to redness, swelling, and soreness. This condition is called balanitis, an inflammation of the head of the penis that is most common in uncircumcised men with inconsistent hygiene habits.
If balanitis keeps coming back, repeated inflammation can cause the foreskin to scar and tighten, making it difficult or painful to pull back. This is called phimosis. In severe cases, the foreskin becomes so tight it can’t be retracted at all, which makes cleaning even harder and creates a cycle of worsening buildup and irritation.
One persistent myth worth addressing: smegma has long been claimed to cause penile cancer. A review published in the Journal of the European Academy of Dermatology and Venereology examined this claim directly and concluded that it cannot be justified on scientific grounds. The association likely arose because poor hygiene and chronic irritation are both risk factors for penile cancer, but smegma itself is not a carcinogen.
How to Prevent Buildup
Cleaning under the foreskin is simple and only needs to happen during your regular shower or bath. Gently pull the foreskin back, rinse the head of the penis and the inner fold of skin with warm water, and slide the foreskin back into place. That’s it. Soap is optional and should be mild if you use it, since harsh soaps or heavily fragranced body washes can irritate the delicate skin and actually make things worse by stripping away protective moisture and triggering more oil production.
If smegma has already hardened, don’t try to scrape or peel it off. Soak in warm water for several minutes to soften it first, then gently wash the area. Forcing dried smegma off can tear the skin and invite infection. Daily washing prevents it from ever reaching that point. For most people, making this a 15-second step in their shower routine is all it takes to keep smegma from becoming noticeable.