Coffee and acne: what the studies measured

Coffee turns up in acne surveys often enough that the question feels settled. It is not. No trial has ever given one group coffee and another group no coffee and then counted spots. Everything that exists is a survey, and surveys record what people drink alongside everything else they eat.

That matters more than it sounds, because of what comes with coffee. Most coffee drinks sold are not black coffee. They carry milk, sugar, or both. Both of those have research behind them for acne. Coffee on its own does not.

What the surveys found

Two large studies have measured coffee and acne in the same population, and reading them together is more useful than reading either alone.

The first is a 2026 cross-sectional study published in Frontiers in Public Health, which surveyed 1,299 students aged 11 to 16 across five junior high schools in Shanghai. Acne was common in this group, affecting 64.43 percent overall.

The researchers recorded how often students drank various things, in three bands: never, sometimes, or daily. Here is what came out of the analysis that adjusted for other factors:

Drink	Odds of acne, compared with not drinking it
Sugar-sweetened drinks	1.56 times (95% CI 1.09 to 2.23)
Coffee	1.43 times (95% CI 1.08 to 1.88)
Milk tea	1.43 times (95% CI 1.07 to 1.92)

Coffee sits in a group of sweet drinks, at the same figure as milk tea. The authors describe a dose-response pattern: students with higher scores on their combined high-sugar and high-fat index had more acne. Their own stated limitation is direct, that the design does not allow for causal conclusions, and that recall bias may exist because the diet information came from face-to-face interviews.

The second study points the other way. A 2021 cross-sectional study in Acta Dermato-Venereologica surveyed 2,476 Thai adolescents and adults, 681 men and 1,795 women. In its first round of analysis, black coffee appeared among the drinks linked to less severe acne. Then the researchers adjusted for everything else people ate, and coffee dropped out. It was not independently associated with acne severity in the final model.

What did survive adjustment in that study is worth reading, because it is a cleaner list of what the diet evidence actually supports:

• Chocolate, more than 100 grams a week: 1.29 times the odds of severe acne
• Oily and fried food, 3 or more times a week: 1.84 times
• White rice: 1.80 times
• Vegetables, 3 or more portions a week: 0.74 times, meaning lower odds
• Tea without sugar or milk, 3 or more glasses a week: 0.61 times

The same paper found that dairy products, sweets and snacks, and sugary drinks did not hold up as independent factors in its multivariate model, which is the opposite of what the Shanghai study found. Two careful surveys in two countries disagreeing is a sign that the real effect, if there is one, is small and hard to separate from everything else a person eats.

There is a reason single drinks are hard to measure this way. The Shanghai researchers built a combined score across several high-sugar and high-fat items rather than relying on any one of them, and found that students scoring higher on that combined measure had more acne, with the pattern rising as the score rose. Read that way, coffee is not acting as a cause in their data. It is acting as a marker for a wider eating pattern, in a group of teenagers where a coffee is usually a sweet coffee. Someone who drinks coffee daily at 13 is also more likely to drink milk tea and sweetened drinks, and a survey cannot separate the three when they are consumed by the same people.

What is in the cup

The clearer story is the additions, not the coffee.

On milk, the American Academy of Dermatology reports that women who drank two or more glasses of skim milk a day were 44 percent more likely to have acne than others. The same page points out that no studies have found yogurt or cheese lead to more breakouts, which is a useful detail: the link is specific to milk, not to dairy in general. The milk and acne guide goes through those studies.

On sugar, the evidence is the strongest in the whole diet-and-acne field. A 2022 systematic review in JAAD International examined 34 articles and concluded that a high glycemic index, increased glycemic load and carbohydrate intake have a modest but real acne-worsening effect. It reported that 77 percent of observational studies supported a link between the glycemic content of the diet and acne. The high glycemic foods guide covers what that means for ordinary meals.

So a large sweetened milky coffee contains two things with evidence against them and one thing with none. Black coffee contains the one with none.

The cortisol argument

A common explanation runs: caffeine raises cortisol, cortisol is a stress hormone, stress causes acne, so coffee causes acne.

The last step is where it breaks. The American Academy of Dermatology is clear that stress cannot cause acne, though stress may worsen acne that a person already has. Beyond that, no study has measured whether a cup of coffee raises cortisol enough to change anything on skin. The chain has never been tested end to end, and treating it as established would mean inventing a result nobody has produced.

Something simpler may explain more. The AAD lists getting too little sleep among the things that worsen acne. Caffeine in the afternoon or evening shortens sleep for many people. If coffee affects your skin, that route is at least made of steps that have each been observed. The sleep and acne guide covers what the research on sleep itself shows.

Coffee grounds on the face

A separate question comes up often enough to answer here. No trial has tested coffee grounds as a face scrub or mask for acne.

Grounds are coarse and uneven. Scrubbing skin that already has inflamed spots tends to irritate it, and irritated skin is harder to treat. Acne forms when pores clog with oil and dead skin cells, and the treatments shown to clear that are applied as gels, creams or washes designed for the job. Nothing about ground coffee does what those do. The home remedies guide covers which kitchen ingredients have been studied and which have not.

How to test your own cup

If your skin does seem to respond to your morning drink, you can test it, and the useful version of the test changes one thing.

Rather than giving up coffee, switch to it black for 8 weeks, keeping everything else the same. That removes the milk and the sugar, the two parts with evidence behind them, while keeping the caffeine. If your skin improves, the additions were the issue. If nothing changes, the drink was not the issue at all, and you have learned that without giving up coffee.

Take photos at the start and at the end, in the same light, because memory is a poor record of skin. Eight weeks is the minimum worth waiting, since skin takes that long to show a response to any change.

The AAD's own framing for food triggers is to ask what happens when you go without something for a day, a week or a month. For acne, the month end of that range is the part that tells you anything.

Where coffee sits among the real causes

It is worth keeping this in proportion. The NHS lists the causes of acne as blocked hair follicles, changes in hormone levels such as during puberty, periods, menopause and pregnancy, certain medicines, and products that make skin greasy. Diet is not on that list at all.

The AAD's own conclusion on food is that diet may play a role in causing or worsening breakouts, and that keeping skin clear requires more than a diet change. A treatment used daily on the skin does more for acne than any drink decision, and the diet and acne guide sets out which foods have evidence and how strong it is.

The NHS says to see a GP if you have tried treating acne yourself and it is not getting better, if you have lots of spots, or if the spots are deep, painful or causing scars. No change to a coffee order substitutes for that.

The honest summary: nobody has tested coffee, the surveys that include it disagree with each other, and the two things in a typical coffee shop drink that do have evidence are the milk and the sugar.