Hair, skin and nail supplements judged on evidence, testing and biotin dose
Top picks
Viviscal
A drug-free hair supplement built on the AminoMar marine complex plus zinc, vitamin C and modest biotin, with company-funded trials; cheaper than Nutrafol but still pricey.
Nutrafol
Dermatologist-favorite hair supplement, NSF Certified for Sport and now biotin-free and vegan; backed by company-funded trials but $88 a month and built on proprietary blends.
An NSF-certified grapefruit gummy with 2,500 mcg biotin, 50 mg keratin and vitamins C and E: well made and well liked, but backed by weak hair-and-nail evidence.
The essentials
Hair, skin and nail supplements promise thicker hair, stronger nails and clearer skin, and they range from $8 bottles of biotin gummies to $88-a-month multi-ingredient hair formulas. Many of the best-selling gummies are built around biotin, often at 2,500 mcg or more per serving, more than 80 times the 30 mcg Daily Value.
The evidence is thinner than the marketing. A 2017 review found that every reported case of biotin improving hair or nails involved an underlying deficiency or condition, and concluded there is not enough evidence to recommend it for healthy people. A 2023 JAMA Dermatology systematic review found the highest-quality, though still limited, evidence for a handful of products and nutrients, including Viviscal, Nutrafol and zinc, rather than for biotin alone. High biotin intakes can also distort some laboratory tests, and the FDA has received reports of falsely low troponin results.
These products make the most sense for adults whose shedding or thinning has been checked by a clinician and who want a low-risk add-on taken consistently for three to six months. Sudden, patchy or severe hair loss needs a medical diagnosis first.
Every product
4 products
Viviscal
A drug-free hair supplement built on the AminoMar marine complex plus zinc, vitamin C and modest biotin, with company-funded trials; cheaper than Nutrafol but still pricey.
Nutrafol
Dermatologist-favorite hair supplement, NSF Certified for Sport and now biotin-free and vegan; backed by company-funded trials but $88 a month and built on proprietary blends.
An NSF-certified grapefruit gummy with 2,500 mcg biotin, 50 mg keratin and vitamins C and E: well made and well liked, but backed by weak hair-and-nail evidence.
Nature's Bounty
A budget biotin gummy with 70,000+ buyer ratings: 2,500 mcg biotin plus a little vitamin C and E for about $0.19 a day; weak evidence it helps without a deficiency.
Buying guide
The five things we look at first — and what they mean for you.
Thinning hair and brittle nails have many possible causes, from nutritional deficiencies and hormonal changes to stress, illness and genetics, and each calls for a different approach. A dermatologist or primary care clinician can check for conditions that need medical treatment. Consider a supplement only as an add-on once those have been ruled out. Take photos of your hairline and part in the same lighting each month so you can judge results honestly.
Beauty gummies and biotin products commonly contain 2,500-10,000 mcg of biotin, yet research suggests it helps mainly people with a deficiency or conditions such as brittle nail syndrome. If you eat a varied diet, extra biotin is unlikely to change your hair. Judge a product on its other ingredients and its evidence, and do not assume a bigger biotin number means a better result.
Many lab tests use biotin-streptavidin chemistry, and high blood biotin can make results falsely high or low. In a 2017 JAMA study, 10 mg of biotin a day for a week interfered with 9 of 23 such assays, and the FDA has received reports of falsely low troponin results. Mention every biotin-containing product, including multivitamins and beauty gummies, before any blood work.
Supplement makers do not have to prove that products work before selling them, so independent testing is the best check that a bottle contains what the label says. NSF/ANSI 173 (NSF Contents Certified), NSF Certified for Sport and USP Verified can all be confirmed in the certifiers' online databases. Of the products we reviewed, Nutrafol and OLLY Undeniable Beauty carry NSF certifications, while Viviscal and Nature's Bounty do not.
Hair grows slowly, and controlled trials of hair supplements typically measure results after three to six months. Multiply the daily cost by 180 to see what a fair trial costs: in our reviews that ranged from about $35 for a budget biotin gummy to more than $500 for a premium hair formula. Gummies also add around 2 g of sugar per serving and often contain gelatin.
Head to head
Ingredients
Video reviews
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