Blackheads form when a pore becomes plugged with a mix of excess oil and dead skin cells, and the surface of that plug darkens as it’s exposed to air. If you’re noticing more of them lately, the cause is almost always a combination of factors: your hormones, your skin’s oil production, and what your pores are exposed to daily. Understanding which factors apply to you makes it much easier to address the problem effectively.
How a Blackhead Actually Forms
Every pore on your face contains a tiny hair follicle and an oil gland. The oil gland produces sebum, a waxy substance that normally travels up through the pore and spreads across your skin to keep it moisturized. A blackhead starts when the cells lining the inside of that pore begin multiplying too fast or fail to shed properly. These dead cells accumulate and form a plug near the surface.
Once that plug is in place, oil backs up behind it. The pore stretches open under the pressure, which is what makes a blackhead an “open” comedo. Because the plug sits at the surface and is exposed to oxygen, the oils in it oxidize and turn dark brown or black. That dark color isn’t dirt. It’s a chemical reaction, similar to how a sliced apple browns when left on the counter.
The process can be triggered by changes in the oil itself. When sebum contains higher levels of certain fats, particularly free fatty acids and oxidized forms of squalene (a natural oil component), it irritates the pore lining and accelerates that buildup of dead cells. A drop in linoleic acid, a protective fatty acid in sebum, seems to make this worse. So it’s not just about producing too much oil; the composition of your oil matters too.
Hormones Are the Biggest Driver
Androgens, the group of hormones that includes testosterone, directly stimulate your oil glands to produce more sebum. This is why blackheads tend to surge during puberty, before a menstrual period, or during other hormonal shifts. The effect is straightforward: more androgens means more oil, and more oil means a higher chance of clogged pores.
Your oil glands contain androgen receptors and enzymes that convert testosterone into a more potent form called DHT. This conversion happens right inside the gland itself, which is why some people with normal blood hormone levels still get oily skin and blackheads. Male skin tends to have higher levels of both the receptors and the converting enzymes, which is one reason men often have larger, more visible pores and more persistent blackheads on the nose and forehead.
Estrogen has the opposite effect, slowing sebum production. This is why some women notice clearer skin on certain birth control formulations and why blackheads can worsen during perimenopause as estrogen levels decline. Insulin-like growth factor (IGF-1) also plays a role: when insulin levels spike, they amplify the effect of testosterone on oil glands, creating a link between what you eat and how oily your skin becomes.
Diet and Blood Sugar Play a Role
Foods that spike your blood sugar quickly, called high glycemic foods, can increase blackhead formation through that insulin connection. When you eat refined carbohydrates like white bread, chips, sugary drinks, or white rice, your blood sugar rises fast. Your body responds by releasing a surge of insulin, which in turn boosts oil gland activity and promotes inflammation in the skin.
Cow’s milk appears to have a similar effect, even though it’s not particularly high in sugar. The whey and casein proteins in milk can elevate blood sugar and insulin levels enough to influence sebum production. This doesn’t mean dairy guarantees blackheads, but if you drink a lot of milk and struggle with clogged pores, it’s worth paying attention to.
Western diets also tend to be high in omega-6 fatty acids (found in vegetable oils, fried foods, and many processed snacks) relative to omega-3s. That imbalance promotes low-grade inflammation throughout the body, including in the skin. None of these dietary factors cause blackheads on their own, but they can amplify the process in someone already prone to oily skin.
Pollution and Your Environment
If you live in a city, airborne particulate matter may be contributing to your blackheads. Research from the EPA has shown that tiny pollution particles can lodge inside hair follicles, where they trigger an inflammatory response and generate reactive oxygen species (molecules that damage cells). Repeated exposure thickens the outer layer of the skin, which can make it harder for oil to flow freely out of pores.
This doesn’t mean pollution alone will give you blackheads, but it adds another layer to the problem, especially if your skin barrier is already compromised from harsh products, over-washing, or dry weather. Cleansing your face in the evening to remove accumulated pollution is more than cosmetic advice; it’s removing material that can physically block and irritate your pores.
Are They Actually Blackheads?
Before overhauling your skincare routine, it’s worth checking whether what you’re seeing are truly blackheads or something called sebaceous filaments. Sebaceous filaments are a normal part of your skin’s structure. They look like tiny dark dots, most often on the nose, but they’re smaller, flatter, and lighter in color than blackheads, typically gray, light brown, or yellowish rather than dark black.
The key difference: blackheads are raised bumps with a dark, solid plug at the surface that blocks oil from leaving the pore. Sebaceous filaments are not plugged. Oil still moves through them freely. If you squeeze a sebaceous filament, a thin, waxy thread comes out, and it refills within about 30 days because it’s just part of how your pore functions. Squeezing won’t fix them because there’s nothing wrong with them.
If you’re seeing dark specks mostly on and around your nose that have been there as long as you can remember, you’re likely looking at sebaceous filaments. True blackheads tend to be more scattered, slightly raised, and distinctly darker.
What Actually Clears Blackheads
Salicylic acid is the most effective over-the-counter ingredient for blackheads specifically. It’s a beta hydroxy acid, meaning it’s oil-soluble and can penetrate into the pore itself, dissolving the mix of dead skin and sebum that forms the plug. Products with 0.5% to 2% salicylic acid, used as a daily cleanser or leave-on treatment, work well for mild to moderate blackheads.
Benzoyl peroxide is the other common option, but its strength is killing bacteria, which makes it better suited for inflamed pimples. It does help clear pores to some degree, but for non-inflamed blackheads, salicylic acid is the more targeted choice. The two can be used together if you have a mix of blackheads and inflammatory breakouts, though introducing both at once can dry out your skin.
Retinoids, which are vitamin A derivatives available over the counter (as adapalene) or by prescription, work by speeding up cell turnover so dead skin cells are less likely to accumulate and form plugs. They’re highly effective for blackheads but come with a transition period. During the first four to six weeks, your skin may actually break out more as deeper clogs are pushed to the surface. This “purging” phase typically resolves by week six to eight, with noticeable improvements in texture and pore size after that point. If you’re still breaking out in new areas after eight weeks, something else is going on.
Why Squeezing Makes Things Worse
Pressing on a blackhead with your fingers can push the plug deeper into the pore rather than extracting it. This forces oil and bacteria further into the surrounding tissue, turning a simple clogged pore into an inflamed, potentially infected lesion. It also damages the walls of the pore itself, which can lead to scarring, especially with repeated attempts in the same spot.
Professional extraction, done by an aesthetician or dermatologist with proper tools and technique, carries far less risk. But even professional extraction is a temporary fix if the underlying causes (excess oil, rapid skin cell turnover, hormonal fluctuations) aren’t addressed. The same pore will clog again within weeks if nothing else changes.
Putting It All Together
Blackheads rarely have a single cause. Hormonal oil production sets the stage, then diet, environment, and skincare habits determine how many pores actually become plugged. If your blackheads appeared suddenly, think about what changed recently: a new medication, a shift in your diet, increased stress (which raises androgen levels), or a move to a more humid or polluted area. If they’ve been a constant presence since your teens, your baseline oil production is likely the primary factor, and a consistent routine with salicylic acid or a retinoid will do the most good over time.