Biotin and acne: what the research shows

Biotin is sold for hair, skin and nails, and Google autocomplete shows dozens of searches asking whether it causes acne. The research is limited. No study has tested biotin as a cause of acne, and the few acne studies that include biotin tested it as a possible help. This guide sets out what is known: what biotin is, where the popular vitamin B5 theory comes from, what the small studies found, and the one well documented risk, which is false results on blood tests. It is part of Skinli's acne diet guide.

Skinli gives general education and is not a doctor or dietitian. Tell your doctor about any supplement you take, and always before a blood test.

What biotin is

Biotin is a B vitamin, sometimes called vitamin B7. The NIH Office of Dietary Supplements (ODS) explains that the body needs it for enzymes that process fats, sugars and proteins. The ODS sets an adequate intake of 30 micrograms a day for adults. It says people in Western countries get 35 to 70 micrograms a day from food, and that biotin deficiency is rare.

Supplements often contain far more. The ODS mentions studies of 2.5 milligrams a day for nails, which is 2,500 micrograms, and it says doses of 10 to 50 milligrams a day have shown no harmful effects. The body absorbs all of an oral dose of free biotin, even at 20 milligrams a day. There is no upper limit for biotin, because no study in people has found it toxic at high intakes.

Signs of biotin deficiency include skin rashes, hair loss and brittle nails, which is why biotin is marketed for those problems. The ODS says evidence that supplements help hair and skin comes only from case reports, mostly in children and infants with rare conditions.

Reading a biotin label

Biotin labels switch between micrograms (mcg) and milligrams (mg). One milligram is 1,000 micrograms. The adult adequate intake from the ODS is 30 micrograms, so a 10 milligram capsule, the dose used in the 2021 isotretinoin trial below, holds 10,000 micrograms, more than 300 times that amount. Check hair, skin and nail blends and multivitamins as well, because they often contain biotin alongside other vitamins.

Raw egg whites

The ODS explains that raw egg whites contain avidin, a protein that binds biotin tightly and stops the body from absorbing it. Cooking changes avidin so it no longer does this. Eating cooked eggs does not block biotin.

The vitamin B5 theory

The most common explanation online for biotin acne involves vitamin B5, also called pantothenic acid. The idea is that extra biotin crowds out vitamin B5, and that less vitamin B5 leads to acne.

Part of this is true. A 2024 review in the International Journal of Molecular Sciences describes a single transporter in the body that carries biotin, pantothenic acid and lipoic acid, and says each one competes with the others for absorption.

The rest has not been tested:

• Vitamin B5 and acne. A 1995 paper in the journal Medical Hypotheses proposed that a lack of pantothenic acid causes acne. A 2014 trial of 41 adults found fewer spots after 12 weeks on a supplement based on pantothenic acid than on a dummy pill. One small trial of a mixed supplement cannot show that low vitamin B5 causes acne.
• Biotin and vitamin B5 levels. Skinli found no study that measured whether biotin supplements lower vitamin B5 enough to matter for skin.
• Biotin and acne. Skinli found no study that tested biotin as a cause of acne.

So the theory links two real facts with a guess. It may turn out to be right, and it has not been shown.

Studies of biotin in acne

Study	Who	What was tested	Result
International Journal of Dermatology, 2021	60 people taking isotretinoin	Isotretinoin with 10 mg biotin a day, or isotretinoin alone, for 4 months	Skin moisture held steady with biotin and fell without it; hair growth measures improved
Italian Journal of Dermatology and Venereology, 2022	30 people with mild to moderate acne	Biotin and probiotic supplement plus an acne gel, 60 days	Acne score fell 37.4 percent; no comparison group
Giornale Italiano di Dermatologia e Venereologia, 2019	Review	Biotin for skin, hair and oiliness	Suggested biotin could be useful in oily skin with blackheads and whiteheads

None of these found biotin made acne worse. None was designed to find that, either. The 2022 study tested a product with several ingredients alongside a gel containing azelaic acid and a retinoid, so it cannot show what biotin itself did. The 2024 review of isotretinoin supplements in Skin Appendage Disorders called the 2021 results promising and said more studies are needed.

A 2024 review of acne supplements in the Journal of Clinical and Aesthetic Dermatology found biotin among the B vitamins in popular acne products. The review states the adult intake as 30 milligrams, a thousand times the 30 micrograms the ODS gives. The ODS figure is the correct one to use.

The same review lists the B vitamins it found in popular acne supplements: B3 (niacinamide), B5 (pantothenic acid), B6, B7 (biotin), B9 (folate) and B12. So a product sold for acne can contain biotin and vitamin B5 together, the two vitamins the popular theory sets against each other. If you want to test one of them, choose a product that contains only that one.

Biotin and isotretinoin

Biotin comes up in acne care mainly because of isotretinoin. The 2024 review in Skin Appendage Disorders says isotretinoin can lower the activity of biotinidase, an enzyme involved in handling biotin, through its effects on the liver. That is the reason researchers tested biotin as a way to ease isotretinoin side effects. In the 2021 trial, the skin of people taking isotretinoin alone lost moisture over 4 months, while the skin of those who also took biotin did not. Skin oil fell in both groups. The review rated the evidence for biotin as adequate and asked for more studies. Ask your prescriber before you add biotin to isotretinoin.

The real risk: false blood test results

The best documented problem with biotin supplements has nothing to do with acne. The ODS says high intakes of biotin can make some laboratory tests give falsely high or falsely low results. Tests affected include thyroid hormone tests and tests for troponin, which doctors use to diagnose a heart attack.

The ODS reports that even a single 10 milligram dose has interfered with thyroid tests taken within 24 hours. The FDA says it has continued to receive reports of falsely low troponin results caused by biotin, and that some lab test makers have fixed the problem while others have not. According to the ODS, the FDA has reported the death of a patient on high-dose biotin whose troponin test gave a falsely low result.

The advice from both is simple. Tell your doctor and the lab about any biotin you take, including hair, skin and nail blends and multivitamins.

A 2025 review in Nutrients adds that biotin can also affect some allergy blood tests. It says the safest approach is to stop biotin at least 48 hours before blood is drawn, and it cites a shorter gap of 8 hours for people taking 10 milligrams a day. Ask the doctor who ordered your test how long to wait. The same review found only two published cases of allergy to biotin itself, both from handling it at work.

If you think biotin is causing your acne

1. Check the timing. Did breakouts start or worsen within weeks or months of starting the supplement?
2. Look at the whole product. Hair, skin and nail blends often contain other ingredients too. Stop the whole product, since you cannot separate them.
3. Stop for a month, the longest period the American Academy of Dermatology (AAD) suggests for testing a suspected trigger. Keep your skincare the same.
4. Compare photos taken in the same light. The progress tracker keeps them in order.
5. Keep treating the acne. The 2024 AAD guideline recommends benzoyl peroxide and topical retinoids. The acne skincare routine covers them, and analyze your skin builds a free plan from a photo.
6. Mention biotin before any blood test, including tests of thyroid hormones, while you are still taking it.

Other supplements with more acne research are covered in zinc for acne and fish oil and acne. If you are taking isotretinoin, ask your prescriber before adding biotin or any other supplement.