Many everyday habits, foods, and environmental factors can make acne worse, even when you’re actively trying to treat it. The most common culprits fall into a few categories: diet, stress, hormonal shifts, skincare mistakes, physical friction, certain medications, and sleep. Understanding which triggers apply to you can make a real difference in how well your skin responds to treatment.
High-Glycemic Foods and Blood Sugar Spikes
Foods that spike your blood sugar quickly, like white bread, sugary cereals, white rice, pastries, and sodas, are among the most well-documented dietary triggers for acne. These high-glycemic foods cause a rapid rise in insulin, which sets off a chain reaction in your skin. Insulin stimulates your body to produce more androgens (hormones that increase oil production) and raises levels of a growth factor called IGF-1. Both of these drive your oil glands to produce more sebum and cause skin cells to multiply faster inside your pores, creating the perfect setup for clogged pores and breakouts.
The connection is strong enough that clinical trials have shown measurable improvement. When young men switched from high-glycemic carbohydrates to low-glycemic alternatives while keeping the rest of their diet the same, both their hormonal markers and acne severity improved. Acne incidence peaks at the same life stage when IGF-1 levels are highest, and adult women with acne tend to have elevated IGF-1 as well. Swapping white bread for whole grain, choosing steel-cut oats over sugary cereal, and reducing soda intake are simple starting points.
Dairy, Especially Skim Milk
Dairy consumption is linked to acne, but not all dairy is equal. A meta-analysis of observational studies found that people who consumed the most dairy overall had roughly 2.6 times the odds of having acne compared to those who consumed the least. Skim milk carried a stronger association than whole milk or low-fat milk, with an 82% increased risk. Total milk consumption of any kind raised acne risk by about 48%.
Interestingly, yogurt and cheese showed no significant association with acne in the same analysis. The reasons aren’t fully settled, but milk contains hormones and bioactive molecules that may amplify the same insulin and IGF-1 pathways involved in high-glycemic diets. If you suspect dairy is a trigger, cutting back on milk (particularly skim) for a few weeks while keeping a skin diary can help you gauge the effect.
Stress and Cortisol
Stress doesn’t just feel bad for your skin. It measurably worsens acne through a direct hormonal pathway. When you’re stressed, your body produces more cortisol, and your oil glands have receptors that respond to it. Elevated cortisol increases sebum production, which contributes to clogged pores and more inflamed breakouts. Clinical studies have found a statistically significant correlation between cortisol levels and acne severity scores.
Your oil glands also have receptors for other stress-related hormones released by the pituitary gland, meaning they can ramp up sebum production independently of your sex hormones. This is one reason people who don’t normally break out can develop acne during high-pressure periods like exams, job changes, or personal crises. The effect creates a frustrating feedback loop: stress causes breakouts, and breakouts cause more stress.
Menstrual Cycle Timing
If you notice your skin gets worse at roughly the same time each month, you’re not imagining it. About 63% of adult women experience more acne lesions in the late luteal phase of their cycle, which is the week before their period starts. Among women who report cyclical flare-ups, 56% say their skin worsens in the week before menstruation, while another 17% notice it during their period itself.
The trigger is a shift in hormone ratios. As estrogen drops in the days before your period, androgens like DHT become relatively more dominant, stimulating oil glands and hair follicles. For most women, these breakouts resolve within a week after menstruation ends. It’s also worth knowing that certain birth control formulations containing androgenic progestins (like norgestrel and levonorgestrel) can increase free testosterone and make acne worse rather than better.
Pore-Clogging Skincare and Makeup
Some ingredients in skincare products, makeup, and even hair products are comedogenic, meaning they physically block pores. Common offenders include acetylated lanolin alcohol, certain plant oils like carrot seed oil, and thickening agents derived from seaweed such as carrageenan. These ingredients don’t lose their pore-clogging properties just because a product is labeled “dermatologist-tested” or because the overall formula is lightweight. The comedogenic nature of an ingredient stays the same regardless of the formulation it’s in.
Hair products are an often-overlooked source. Oils, pomades, and leave-in conditioners that contact your forehead, temples, or jawline can cause breakouts in those areas. If your acne is concentrated along your hairline or the sides of your face, check your hair products as well as your skincare routine. Look for products labeled “non-comedogenic” and cross-reference the ingredient list rather than trusting marketing claims alone.
Physical Friction and Pressure
Acne mechanica is the clinical term for breakouts caused by repeated pressure, friction, rubbing, or stretching of the skin. Tight helmet straps, football shoulder pads, backpack straps, bra straps, and snug headbands are classic triggers. Truck drivers historically develop it on their backs from prolonged pressure against the seat. Holding your phone against your cheek can do the same thing along your jawline.
The friction traps sweat and oil against the skin while irritating the follicle lining, making it easier for pores to become blocked and inflamed. If your breakouts are concentrated in areas where something regularly presses or rubs against your skin, the solution is often straightforward: loosen the strap, use a speakerphone, or place a clean barrier (like a cotton cover) between the object and your skin.
Poor Sleep
Sleep deprivation raises inflammation throughout the body, and your skin is no exception. When you don’t sleep enough, your body produces more pro-inflammatory signaling molecules (cytokines) that can worsen acne. Cortisol levels also rise with poor sleep, compounding the effect on your oil glands. A genetic analysis using a method called Mendelian randomization found that longer sleep duration was protective against acne, while insomnia increased the risk of inflammatory skin conditions.
The relationship is bidirectional. Inflammatory skin conditions can disrupt sleep, and disrupted sleep worsens inflammation, creating a self-reinforcing cycle. Skin also does much of its repair work overnight, relying on circadian rhythms to regulate barrier function and cell turnover. Consistently getting less than adequate sleep undermines both of those processes.
Certain Medications and Supplements
A surprisingly long list of medications can trigger acneiform eruptions, which look like acne but are driven by the drug rather than by the usual pore-clogging process. The most well-known culprits are corticosteroids, particularly at high doses or when given intravenously. Steroid-induced breakouts tend to appear predominantly on the chest and back rather than the face. Other medications associated with drug-induced acne include lithium, certain anticonvulsants, immunosuppressants, some antibiotics, and thyroid hormones.
Supplements can also be a hidden trigger. Vitamin B12 alters the behavior of acne-causing bacteria on the skin. When B12 levels rise, these bacteria reduce their own B12 production and instead ramp up production of porphyrins, compounds that promote inflammation. In case reports, acneiform eruptions have appeared within days of a B12 injection, presenting as uniform red bumps and pustules across the nose, cheeks, and chin area. Vitamins B1 and B6 have also been linked to breakouts. If you started a new supplement and noticed your skin worsening shortly after, it’s worth examining the ingredient list for high-dose B vitamins.
Air Pollution
Airborne pollutants including fine particulate matter (PM2.5), nitrogen dioxide, and polycyclic aromatic hydrocarbons can worsen acne through several mechanisms. These particles are small enough to settle into pores and on the skin’s surface, where they generate oxidative stress, deplete the skin’s natural antioxidants, and trigger inflammation. Pollution exposure can also disrupt the skin’s barrier function and alter the balance of microbes living on the skin, both of which create conditions favorable for breakouts and increased sebum production.
If you live in a high-pollution area or commute through heavy traffic, cleansing your skin thoroughly at the end of the day becomes especially important. Antioxidant-containing skincare products may also help counteract some of the oxidative damage, though the most effective strategy is simply removing pollutant residue before it has prolonged contact with your skin.