Whiteheads are small, flesh-colored or white bumps made of a plug of oil, dead skin cells, and bacteria trapped inside a closed pore. The plug forms when the pore’s opening is so narrow that air can’t reach the material inside, which is why whiteheads stay white or pale instead of darkening like blackheads. Understanding what goes into that plug, and how it forms, helps explain why whiteheads behave the way they do and what actually works to clear them.
The Three Ingredients Inside a Whitehead
A whitehead is technically called a closed comedone, and its contents are straightforward: sebum, keratin-rich skin cells, and bacteria. Sebum is the oily substance your skin naturally produces to keep itself moisturized. Keratin is the structural protein that makes up the outer layer of your skin, your hair, and your nails. Under normal conditions, dead skin cells lining the inside of a pore shed and get carried to the surface by flowing sebum. In a whitehead, that process breaks down.
The dead skin cells become sticky. Instead of shedding one by one, they clump together and form a dense mass inside the pore. Sebum continues to be produced behind this growing blockage but has nowhere to go. Bacteria that normally live on the skin’s surface, particularly a species that thrives in oily environments, get sealed inside the pore along with everything else. The result is a small, pressurized pocket of oil, protein, and microbes sitting just beneath the skin’s surface.
How the Plug Actually Forms
The process starts well before you ever see a bump. A microscopic blockage called a microcomedone begins forming inside the pore roughly eight weeks before a whitehead becomes visible on your skin. That’s a surprisingly long lead time, which is why breakouts can feel random even though they’ve been building for weeks.
It begins with the skin cells lining the upper part of the hair follicle. Normally, these cells divide, move upward, die, and flake off. In whitehead-prone skin, the cells multiply faster than usual and develop stronger physical connections to each other. They essentially stick together rather than separating and shedding. This creates a thickening layer of cells inside the pore that starts to narrow the opening.
At the same time, sebum production increases. The oil mixes with the clumps of dead cells and forms what dermatologists describe as a keratin-sebaceous plug. There’s also evidence that bacteria living in the pore produce a sticky, glue-like substance that further cements the dead cells together, making the blockage harder for the body to clear on its own. The pore’s tiny opening gets sealed, trapping everything inside. Because air can’t reach the contents, there’s no oxidation reaction, and the plug stays white or skin-colored.
Why Whiteheads Stay White and Blackheads Turn Dark
The difference between a whitehead and a blackhead comes down to one thing: whether the pore is open or closed. Blackheads form in pores with wide openings. Air reaches the trapped material, and a pigment called melanin (already present in the dead skin cells) undergoes a chemical reaction with oxygen. That oxidation turns the surface of the plug dark brown or black. It’s not dirt.
Whiteheads form in pores where the opening is extremely small or completely sealed over by a thin layer of skin. No air gets in, no oxidation occurs, and the plug keeps its original pale color. Both types contain essentially the same mixture of oil, dead cells, and bacteria. The color difference is purely about exposure to air.
Why Some People Get More Whiteheads
Hormones play the biggest role. Androgens, a group of hormones that includes testosterone, directly stimulate the oil glands in your skin to grow larger and produce more sebum. They do this by binding to receptors on both the oil glands and the skin cells lining the pore. This is why whiteheads are so common during puberty, before menstrual periods, and in conditions like polycystic ovary syndrome, all situations where androgen levels shift.
More oil production alone doesn’t guarantee whiteheads, though. The critical combination is excess oil plus abnormal cell shedding inside the pore. Some people’s skin cells are simply more prone to clumping. Genetics influence how many connections form between the cells lining your pores, how quickly those cells divide, and how much sebum your glands produce. Products that are heavy or occlusive can also contribute by physically blocking pore openings from the outside, mimicking the closed-pore conditions that create whiteheads.
What Breaks Down the Plug
Since whiteheads are made of sticky dead cells cemented together with oil, effective treatments work by dissolving that bond or preventing it from forming in the first place.
- Salicylic acid works by dissolving the cement-like substance that holds dead skin cells together inside the pore. It’s oil-soluble, so it can actually penetrate into the clogged follicle rather than just sitting on the skin’s surface. This makes it particularly effective for breaking apart existing plugs.
- Retinoids (vitamin A derivatives available over the counter and by prescription) take a different approach. They make the skin cells lining the pore less adhesive, so instead of clumping, the cells separate and shed normally. Retinoids also reduce oil gland size and oil output over time. They work on the formation process itself, which is why they’re considered the most effective long-term option for preventing whiteheads from developing.
Because a whitehead has been forming for up to eight weeks before it appears, treatments that target the formation process need consistent use over several weeks before you see results. A retinoid applied today is preventing the microcomedones that would have become visible whiteheads two months from now. This is the main reason people abandon effective treatments too early, expecting overnight improvement from a process that operates on a much longer timeline.
Why Squeezing Whiteheads Backfires
The plug inside a whitehead sits in a sealed pocket with a very narrow or fully closed opening. Squeezing forces the contents deeper into the surrounding skin rather than pushing them out cleanly. This can rupture the follicle wall beneath the surface, spilling bacteria and inflammatory material into the surrounding tissue and converting a mild, noninflammatory whitehead into a red, swollen, painful pimple. The thin layer of skin covering a whitehead might look easy to breach, but the pressure required almost always does more damage below the surface than above it.