Does Dairy Cause Acne? What the Studies Show About Milk, Cheese and Yogurt

There is no proof that dairy causes acne. Large observational studies do find that people who drink more milk have modestly higher odds of acne, with the strongest links for skim and low-fat milk, while the links for cheese and yogurt are weaker or absent. Because none of this research can show cause and effect, and one genetic study found no link at all, dairy looks like a possible trigger for some people rather than a rule for everyone.

That is a long way from the advice that floods search results and social feeds: cut all dairy and your skin will clear. Here is what the studies measured, how strong each finding is, and how to find out whether dairy matters for your own skin.

What does the research say about dairy and acne?

Most of the evidence comes from two meta-analyses that pooled observational studies, plus a handful of large cohorts.

• A 2018 meta-analysis in Nutrients combined 14 studies covering 78,529 people aged 7 to 30. Any dairy was linked with 25% higher odds of acne (odds ratio 1.25). Milk drinkers who had one glass a day had about 41% higher odds than people who drank milk less than weekly. The authors flagged publication bias and noted that the links shrank once studies adjusted for other factors, so they asked readers to interpret the results with caution.
• A 2019 meta-analysis in Clinical Nutrition found similar links for total milk (odds ratio 1.48) and the strongest for skim milk (1.82). It found no significant link for yogurt or cheese.
• A 2022 systematic review in JAAD International looked only at higher-quality studies. It called the dairy evidence "mixed" and said any effect may depend on sex, ethnicity and dietary habits, showing up mainly where a Western diet is common. The same review found more consistent evidence for high-glycemic diets, which were also tested in randomized trials.

Two large studies show how modest and inconsistent the dairy signal is in adults:

The Danish study matters because of its design. Mendelian randomization uses genes as a natural experiment, which avoids some of the confounding that limits ordinary diet surveys. Finding nothing doesn't disprove a link, but it is a reason to doubt that milk is a major driver of acne across the board.

Why might milk affect skin?

Researchers have proposed a few routes, mostly from lab and hormone studies rather than acne trials:

1. Insulin and IGF-1. Drinking milk raises insulin and IGF-1, a growth hormone that also rises in puberty. IGF-1 signals oil glands to grow and make more sebum, and acne tends to track IGF-1 levels during the teenage years.
2. Milk proteins. Whey and casein are strongly insulin-raising, which may explain why reviews suspect the protein, not the fat, does most of the work. That would fit the skim milk finding, since some skim milk is fortified with extra milk solids, though this explanation hasn't been tested directly.
3. Hormones in milk. Milk naturally contains small amounts of hormones and hormone precursors. Whether they reach the skin in meaningful amounts isn't clear.

These mechanisms are plausible, but plausibility isn't proof. They also apply to high-glycemic foods, which raise insulin too, and that is one reason the two often get blamed together. The guide on sugar and acne covers what the low-glycemic diet trials found.

Is cheese or yogurt different from milk?

Probably, though the data are thin. The 2019 meta-analysis found no significant link for yogurt or cheese, while the 2018 analysis found small links (1.36 for yogurt, and a borderline 1.22 for cheese). Fermentation uses up much of the milk sugar and changes some of the proteins, and cheese is usually eaten in smaller amounts than milk is drunk. Treating every dairy food as the same trigger isn't supported by the research.

Does whey protein cause acne?

Whey is the dairy question that comes up most among people who train. A 2020 review of supplement-related acne describes case reports of breakouts on the chest, back and face in whey users, usually settling after they stopped. Some "muscle building" products are also contaminated with steroids, which are known to cause severe acne.

The only controlled trial is reassuring. In a 2024 double-blind study, 49 men aged about 20 with mild to moderate acne took either 30 grams of whey a day or a non-whey supplement for six months. Acne lesions and severity were no worse in the whey group. The trial was small and only included men, so it doesn't settle the question, but it argues against assuming whey is a problem for everyone.

Should you cut dairy for acne?

The research doesn't support cutting all dairy as a general acne strategy. The 2024 American Academy of Dermatology guidelines base their recommendations on treatments such as benzoyl peroxide, retinoids and oral medications, not on diet. Cutting dairy also has costs: it removes foods many people enjoy, and milk and yogurt are major sources of calcium, protein and vitamin D for many diets.

What the research does support is that some people may react to some dairy. Forum threads on acne.org show both sides: some people report clearer skin after switching from cow's milk, while others went dairy-free for four to six months and saw no change. Both can be true, because skin responds individually.

What this means for your skin

If you suspect dairy, test it rather than guess. A structured test tells you more than a blanket cut.

• Start with milk, not all dairy. Milk, especially skim, has the strongest link in studies. Keep cheese and yogurt and change one thing at a time.
• Give it at least 4 to 6 weeks. Acne changes slowly, and 8 to 12 weeks gives a clearer answer. Keep your skincare and acne treatment the same throughout.
• Bring it back on purpose. After the break, reintroduce one dairy type and watch the next two weeks. A reaction that repeats is more convincing than one bad week.
• Check the protein shake. If you take whey, it is the easiest single item to pause and test.
• Look at the rest of the plate. Sugary drinks and high-glycemic snacks showed links as strong as milk in the French cohort, and they often travel with dairy (milkshakes, sweetened lattes, ice cream).
• Protect the nutrients. If you do drop milk, choose a calcium-fortified alternative and talk to a doctor or dietitian, especially for teenagers.

Logging is what turns a hunch into an answer. The Root Cause app scans your meals and your skin, then looks for the foods that line up with your breakouts over time, so you can see whether dairy is one of your triggers instead of cutting it on someone else's advice. For more on how diet interacts with the rest of the body, see the guide on gut health and acne.

The bottom line

Dairy, and milk in particular, is associated with slightly higher odds of acne in observational studies, with skim milk showing the strongest links. Cheese and yogurt show weaker or no links, a genetic study in adults found nothing, and no trial has shown that cutting dairy clears acne. If you suspect it, test milk on its own for several weeks while keeping your treatment steady, and track how your own skin responds. Keep the foods that don't affect you.