Whey protein and acne: shakes, isolate, back acne

Whey is the protein in most gym shakes, and it comes from milk. Doctors have published reports of acne after starting whey since at least 2012. The evidence is still limited: a few case reports, one study of gym users and one controlled trial that found no harm. This guide covers what each study found, what isolate means for acne, why back acne comes up, and what to do if you think your shake is the cause. It is part of Skinli's acne diet guide. For milk as a drink, see milk and acne.

What whey protein is

Cow's milk contains two main kinds of protein. A 2021 review in the American Journal of Clinical Dermatology says 80 percent of milk protein is casein and 20 percent is whey. A 2017 report explains that whey protein comes from the liquid left over when cheese is made.

A 2024 review in the journal Healthcare describes the main forms sold:

Form	Protein content	Other contents
Whey concentrate	20 to 85 percent	Varying amounts of fat, lactose and minerals
Whey isolate	90 to 95 percent	Minimal fat, lactose and minerals
Hydrolyzed whey	Varies	Protein broken down for faster absorption

Lactose is the sugar in milk. The theory linking whey to acne is about the whey proteins, and isolate contains the most protein per scoop. No study has compared isolate with concentrate for acne.

What the studies found

Study	Who	Design	Finding
Cutis, 2012	5 boys aged 14 to 18	Case reports	Acne began soon after starting whey and cleared in 4 after stopping
Dermatology, 2012	5 adult male bodybuilders	Case reports	Acne developed after starting whey
Health Promotion Perspectives, 2017	6 teenage boys	Case reports	Acne on the back and chest only, starting an average of 3.1 months after starting protein supplements
Six-country online survey, 2020 (in a 2022 review)	6,679 people aged 15 to 39	Cross-sectional survey	Whey users had almost 4 times the odds of acne
Dermatology Research and Practice, 2024	201 male gym users in Jordan	Case-control	47 percent of men with acne had used whey in the past 3 months, against 27.7 percent of men without acne
Journal of Dermatology, 2024	49 men in Thailand, mean age near 20	Double-blind randomized trial, 6 months	30 grams of whey a day was no worse for acne than a supplement without whey

The case reports

In the 2012 Cutis report, 5 boys developed acne shortly after starting whey. Three used it for football training and two to gain weight. All five responded poorly to standard acne treatment: antibiotic tablets, retinoid creams and benzoyl peroxide. Four stopped whey and their acne cleared fully. One restarted whey and his acne flared again within a week. The boys had used at least 6 different brands, both shakes and powders.

Case reports show that something happened to a few people. They cannot say how common it is, and the acne might have had other causes. The Cutis authors concluded that whey may be the part of dairy that promotes acne, and called for larger studies.

The gym study from Jordan

The 2024 study from Jordan compared 100 men with acne and 101 men without it, all using fitness centers. The two groups were similar in age, weight, education, smoking and use of steroids. Whey use was more common in the acne group, and the difference held after other factors were accounted for. The authors say their design and small size limit the result, and that larger studies should follow.

A large online survey

A 2022 systematic review in JAAD International, a journal of the American Academy of Dermatology, lists one larger survey. Researchers recruited 2,826 people with acne and 3,853 people without it, aged 15 to 39, over the internet in France, Germany, Italy, Brazil, Canada and Russia. People who used whey protein had almost 4 times the odds of acne. The review points out two limits. People chose to take part online, so the groups may differ in ways the survey did not measure. The survey also asked only yes or no about each food, with no amounts.

The same review searched for trials that gave people whey or casein and then measured their acne. As of its search, it found none. The Thai trial below was published in 2024, after that review.

The controlled trial

The 2024 trial from Thailand is the strongest test so far. Forty-nine young men with mild to moderate acne on the face or body were randomly assigned. One group took 30 grams of whey a day plus a nutrition supplement. The other took a nutrition supplement with no whey. Neither the men nor the doctors knew who had which. After 6 months, acne counts and severity in the whey group were no worse than in the other group, within the limit the study set in advance.

The trial has limits too. It included only men, only mild to moderate acne, and one dose of 30 grams a day.

Why whey might affect skin

The 2021 review explains the leading theory. Whey proteins cause most of the insulin rise that milk triggers. Higher insulin raises IGF-1, a growth hormone, and IGF-1 can make the skin produce more oil. The review adds that whey concentrate contains 14 grams of leucine in every 100 grams of protein. Leucine is an amino acid that switches on a growth signal inside cells, which researchers also connect to acne.

This is a theory built from laboratory and hormone studies. It explains why whey could matter. It has not been proven in people with acne.

Back and chest acne

Several reports mention acne on the body. The 2017 report described 6 teenage boys with acne only on the back and chest, and the face clear. The authors suggested that friction and sweat on the back during exercise could add to the effect. In the Jordan study, 80 percent of men with acne had it on the face and 43 percent on the back.

Sweat and clothing matter for body acne as well. The NHS advises loose, breathable clothing when exercising or sweating if you have acne on your body. If your breakouts are on your back and chest, read back acne too.

Women, teens and creatine

• Women. Every study of whey and acne so far included only men or boys. Nobody knows whether the results apply to women.
• Teenagers. Most case reports describe teenage boys who started whey for sport or weight gain.
• Creatine. In the Jordan study, creatine use was no different between men with and without acne. A search of PubMed on 26 September 2026 found no study of creatine and acne.

What the research cannot tell you yet

The 2024 review in Healthcare describes the whey and acne research as scarce and mostly limited to single case reports, and its summary table calls the results mixed, with a possible link in some people. Several questions have no answer so far:

• How much whey matters. The trial tested one dose, 30 grams a day. The case reports and surveys did not measure amounts in a way that can be compared.
• Which people react. The case reports describe a few people whose acne flared. The trial found no average effect in 25 men. Both can be true if only some people react, and no study has shown how to tell in advance who they are.
• Whether the form matters. Concentrate, isolate and hydrolyzed whey have not been compared.
• Women. No study has included them.

What the guidelines say

The 2024 acne guideline from the American Academy of Dermatology (AAD) reviewed the research on diet. It found the evidence insufficient to make a recommendation on a low-whey diet for acne. NICE, which writes health guidance for England, says there is not enough evidence to support specific diets for treating acne. The AAD's public advice is to watch whether a food seems to trigger breakouts, then see what happens without it for a day, a week or a month.

What to do if you think whey is the cause

1. Look at the timing. Did your acne start or worsen within a few months of starting a shake?
2. Stop whey for a month. Keep your skincare, other supplements and training the same, so whey is the only change.
3. Take photos in the same light at the start and end. The progress tracker keeps them in date order.
4. Tell your doctor, especially if your acne is not responding to treatment. The 2012 case reports describe acne that improved only after whey stopped.
5. Keep treating the acne. Stopping a supplement is one step. The acne skincare routine covers the rest, and a free plan from a photo is at analyze your skin.

If you need extra protein for sport or weight gain, a doctor or registered dietitian can suggest other sources. Skinli found no acne research on plant protein powders, so switching to one is a personal test with no research behind it. See a doctor about acne that is deep, painful or scarring, whatever you eat.