Acne that won’t clear up usually isn’t a willpower or hygiene problem. It’s driven by a combination of biological factors, and when one or more of those factors stays active, breakouts keep coming back no matter what you put on your skin. Understanding which of these forces is at work helps explain why your current approach isn’t enough and what actually needs to change.
The Four Factors That Keep Acne Going
Acne requires four things happening at once: excess oil production, clogged pores, bacteria, and inflammation. Your sebaceous glands produce too much oil, often driven by hormones. Dead skin cells that should shed naturally instead stick together and plug the opening of the hair follicle. A bacterium called C. acnes colonizes that clogged, oily follicle and triggers an immune response. The result is redness, swelling, and the stubborn bumps you see in the mirror.
The reason acne persists is that most treatments only target one or two of these factors. A cleanser might reduce surface oil but do nothing about hormonal overproduction. An antibiotic might kill bacteria but leave the clogging and oil untouched. If even one of the four factors remains unchecked, the cycle restarts.
Hormones Are the Most Common Hidden Driver
Hormonal changes increase the amount of oil your skin produces, and this is the single biggest reason acne sticks around into adulthood. Androgens, the hormones most responsible, stimulate your oil glands directly. Some people’s skin converts testosterone into a more potent form at higher rates than average, which means even normal hormone levels in your blood can cause excess oil at the skin level.
For women, hormonal acne flares around periods, during pregnancy, around menopause, or after stopping birth control. Conditions like polycystic ovary syndrome (PCOS) are a major culprit. PCOS causes the ovaries to produce unusually high levels of androgens, and the acne it produces tends to appear on the jawline, back, and chest. It’s often resistant to standard treatments. If your persistent acne comes with irregular periods, unusual hair growth on your face or body, or difficulty maintaining your weight, PCOS is worth investigating. Up to 70% of people with PCOS experience excess hair growth, and between 40% and 80% have obesity.
Insulin resistance also plays a direct role. When your body produces more insulin, it raises levels of a growth factor called IGF-1, which stimulates your oil glands to produce more sebum. This connection explains why acne is more common in people with PCOS and other conditions involving insulin resistance, and it’s one of the reasons diet matters more than people realize.
Your Diet May Be Fueling Breakouts
High-glycemic foods (white bread, sugary drinks, processed snacks) cause rapid spikes in blood sugar and insulin. That insulin spike raises IGF-1 levels, which directly increases oil production in the skin. Elevated IGF-1 activates a specific pathway in oil gland cells that ramps up fat production inside them, essentially making your pores oilier from the inside out.
This doesn’t mean diet causes acne on its own, but if you’re already prone to breakouts, a diet heavy in refined carbohydrates and sugar is actively making them worse. Dairy, particularly skim milk, has also been linked to acne in several studies, possibly because of the hormones and growth factors naturally present in milk.
Your Bacteria May Be Resistant to Treatment
If you’ve used topical antibiotics like clindamycin or erythromycin for a while without lasting results, bacterial resistance is a likely explanation. A large meta-analysis covering over 2,000 bacterial samples found resistance rates of about 29% for erythromycin and 22% for clindamycin, with those rates climbing over time. Resistance to common oral antibiotics in the macrolide class (the family that includes azithromycin and clarithromycin) was even higher, ranging from 43% to 48%.
C. acnes also forms biofilms inside hair follicles, essentially building a physical shield that blocks antibiotics from reaching the bacteria. This is one reason why antibiotic monotherapy (using an antibiotic alone, without benzoyl peroxide or a retinoid) tends to fail over time. Combining an antibiotic with benzoyl peroxide helps prevent resistance, which is why dermatologists almost always pair them together.
You Might Not Be Giving Treatments Enough Time
The top layer of your skin replaces itself roughly every 28 to 30 days. That means any treatment affecting how skin cells form, shed, or behave needs at least one full turnover cycle before it can show results. Most inflammatory acne treatments require 8 to 12 weeks to produce meaningful improvement. Dermatologists typically don’t reassess until the two to three month mark because judging a treatment before then isn’t reliable.
Switching products every few weeks, a common pattern when you’re frustrated, means you never reach the point where any single treatment has a fair chance to work. If you start a new product and break out in the first few weeks, that’s often a normal adjustment period (sometimes called purging with retinoids), not a sign the product is failing.
Your Skincare Routine May Be Making Things Worse
Over-cleansing is one of the most common mistakes. Your skin is naturally slightly acidic, with a healthy pH between 4.0 and 5.0. Harsh cleansers, excessive scrubbing, and too-frequent exfoliation strip away the skin’s protective barrier. When that barrier breaks down, your skin becomes more prone to infection, increased inflammation, and paradoxically, more acne. A damaged barrier also triggers your oil glands to compensate by producing even more sebum.
Signs that your barrier is compromised include persistent dryness alongside breakouts, stinging when you apply products that didn’t used to sting, and skin that looks irritated and red beyond just the acne itself. If this sounds familiar, scaling back to a gentle cleanser and a simple moisturizer for a few weeks can help your skin recover before you reintroduce active treatments.
Choosing the Right Active Ingredients
For over-the-counter options, benzoyl peroxide and salicylic acid are the two most effective ingredients, but they work differently. Salicylic acid (available in concentrations from 0.5% to about 7%) dissolves the dead skin cells plugging your pores. Benzoyl peroxide kills acne-causing bacteria and helps prevent antibiotic resistance. Start with a 2.5% benzoyl peroxide product. If you see minimal improvement after six weeks, move up to 5%. A 10% concentration is rarely necessary and causes significantly more dryness and irritation.
When Standard Treatments Fail
Isotretinoin (often known by its former brand name, Accutane) is the most effective treatment for acne that hasn’t responded to other approaches. It works by dramatically shrinking oil glands and addressing all four acne factors at once. However, it’s not a guaranteed permanent fix. Relapse rates after a full course range from 10% to 60%, depending on the dose used and the patient population. Taking a total cumulative dose below a specific threshold is a known predictor of relapse, which is why dermatologists aim for a full course rather than stopping early when skin looks clear.
Men have roughly double the relapse risk compared to women. For women, taking antiandrogen therapy after finishing isotretinoin reduced relapse risk by about 72% in one study. Those who didn’t had 3.5 times the risk of their acne returning. Using a topical retinoid as maintenance after isotretinoin also provided measurable protection, with about a 32% reduction in relapse risk for each month of continued use.
Underlying Conditions Worth Ruling Out
Persistent acne that doesn’t respond to well-chosen treatments can be a signal that something else is going on hormonally. PCOS is the most common culprit in women, but other possibilities include adrenal gland conditions that cause excess androgen production and a genetic enzyme deficiency called 21-hydroxylase deficiency. In men, testosterone supplementation is a well-known trigger for stubborn acne.
A few patterns suggest a hormonal evaluation is worthwhile: acne concentrated along the jawline and lower face, flares that track your menstrual cycle, acne that first appeared or dramatically worsened in your twenties or thirties, and breakouts accompanied by other signs like hair thinning on your scalp, excess body hair, darkening skin in body folds, or irregular periods. Blood work can check androgen levels and insulin markers, and the results often change the treatment approach entirely.