Supplements that promise to support the health of hair, skin and nails are growing in popularity, but they can come with “significant risk” and there’s limited evidence to show they offer any benefits, dermatologists warn in a new analysis.
The use of hair, skin and nail supplements has almost doubled in recent years, according to the research letter, published in the July 2023 issue of the Journal of the American Academy of Dermatology.
The portion of Americans who reported taking such a vitamin in the past month jumped from 2.5% to 4.9% in the decade ending in 2020, the analysis found. The numbers are based on data from about 40,000 Americans taking part in the National Health and Nutrition Examination Survey.
The rise may be driven in part by celebrities and social media influencers promoting the pills, the authors note.
The appeal of beauty
Consumers who were most likely to report using hair, skin and nail supplements included women, Black and Hispanic people, and adults 20 to 39 years old, according to the analysis.
The growing numbers reflect what dermatologists are seeing in their offices: More and more patients ask about these supplements and use them, says Dr. Rebecca Hartman, study co-author and assistant professor of dermatology at Harvard Medical School.
“It’s the appeal of beauty,” Hartman, who is also associate chief of dermatology at the VA Boston Healthcare System, tells TODAY.com.
“People want to look their best, feel their best and present their best self to the world, so they’re interested if there’s a quick fix or a supplement that can help them… (but) from my perspective, the risks outweigh the benefit in that there’s not a lot of great evidence for them.”
Dietary supplements are regulated as food, not as drugs, by the U.S. Food and Drug Administration, so “they have no endorsement from the FDA in terms of safety and effectiveness, and I think that’s the biggest issue,” Hartman says.
The quality assurance is very difficult to assess with many of these products, adds Dr. Adam Friedman, professor and chair of dermatology at the George Washington School of Medicine and Health Sciences.
“I don’t think many will do much of anything,” says Friedman, who was not involved in the new study.
The analysis focuses on risks associated with two common supplements: biotin and collagen.
Both are safe when used as directed, says Haiuyen Nguyen, vice president of regulatory and nutrition policy at the Council for Responsible Nutrition, a trade group that represents dietary supplement manufacturers, in a statement to TODAY.com.
But the paper highlighted a number of concerns:
Also known as vitamin B7, it's often marketed for hair growth. But biotin in high doses can interfere with tests that measure thyroid and heart function, the authors note.
“It can give a false appearance of hyperthyroidism by making it look like your thyroid is overacting,” Hartman says. “It also can give up a falsely low level of troponin, which is a really important cardiac test that’s used to identify a heart attack in the hospital.”
The daily recommended allowance for biotin is 0.03 milligrams for adults, but many dietary supplements promoted for hair, skin, and nail benefits have levels up to 650 times that amount, “with recommendations to take multiple pills per day,” the FDA notes.
The agency began warning in 2017 that biotin interference with certain lab tests may lead to faulty results.
In one instance, daily biotin supplements taken by a 48-year-old woman caused such abnormal test results that they almost led to an unnecessary surgery when doctors thought she might have a “testosterone-producing tumor,” according to a case report in the Journal of the Endocrine Society. When she stopped taking biotin, her test results normalized.
If you are currently taking a biotin supplement or are considering adding it to your diet, tell your doctor, the FDA advises. Biotin supplementation can "clearly impact healthcare," and doesn't do much for hair, Friedman notes.
Supplementation isn’t necessary for most people eating a healthy diet, Hartman adds. Foods that contain the most biotin include organ meats, eggs, fish, meat, seeds, nuts and vegetables like sweet potatoes, according to the National Institutes of Health Office of Dietary Supplements.
The concern here is contamination, the new analysis warns. The authors point to findings by the Organic Consumers Association and the Clean Label Project, which tested 28 of the top-selling brands of collagen supplements on Amazon.com in 2020.
The results showed 64% tested positive for arsenic, 37% tested positive for lead, 34% tested positive for trace levels of mercury and 17% tested positive for cadmium.
These toxic heavy metals may occur naturally in the environment, the FDA notes. Manufacturers can control for levels of contaminants in dietary supplements through good manufacturing practices, Nguyen adds.
Collagen is the most abundant protein in the body and it helps maintain healthy skin, according to nutritionist Keri Glassman.
But we have less of it as we age, which affects “that bouncy and thick texture of your skin,” Hartman says. While it’s too big to penetrate the skin topically, there is some evidence supporting the use of oral collagen supplements for skin aging, Friedman adds.
Bone broth is a good food source of collagen, and collagen formation also requires vitamin C, zinc, copper and certain amino acids, so eating foods with these nutrients can be helpful, she notes.
But there’s no optimal dose for collagen supplementation and there’s concern the gut can break down any collagen a person takes in the form of foods and supplements, Hartman points out.
If you still want to take hair, skin and nail vitamins, look for products with third-party validation from organizations such as the NSF or the USP, which test supplements and certify they contain the ingredients listed on the label and don't have contaminants, Hartman advises.
Tell your doctor if you are taking any supplements to avoid any potential drug interactions and, in the case of women trying to conceive or who are already pregnant, reduce any potential risk to the fetus.
Take care of your hair, skin and nails by eating plenty of protein, healthy fats, and fruits and vegetables; and by using sun protection to avoid the sun’s damaging rays, Hartman adds.