5 best biotin supplements for hair growth 2025, recommended by dieticians
.jpg)
If you’re like us, your FYP is probably flooded by folks swearing by biotin supplements for hair growth, but do they work?
First, a bit of background: Biotin is a B vitamin known for promoting healthy hair and helping with brittle nails. It’s essential for the process by which cells create proteins. “Since our hair and nails are made of keratin, a type of structural protein, a biotin deficiency will negatively impact hair and nail growth,” says Kseniya Kobets, director of cosmetics dermatology at Montefiore Einstein Advanced Care. One major symptom of biotin deficiency is alopecia (hair loss). But here’s the kicker: if you aren’t deficient in biotin (most people aren’t, FYI), taking biotin supplements probably won’t do much for you. The data on taking biotin to help grow your hair, skin, and nails just isn’t there. But anecdotally, many reviewers we spoke to say saw improvements in these areas after taking biotin — even when they’re not deficient.
So, what’s a gal looking to grow her strands to do? We spoke with dermatologists and dieticians for their recommendations on the best biotin supplements for hair growth. And a quick reminder that supplements are not always regulated, so it’s always best to do your own research and check in with a doctor before adding one to your diet, especially if you take any medications.
All your biotin questions, answered
What exactly is biotin?
Biotin goes by two other names — vitamin B7 and vitamin H — and plays a role in the production of keratin, a protein essential for healthy skin, hair, and nails. It’s a water-soluble vitamin, meaning it doesn’t build up in your body; rather, you excrete the excess through urine.
The recommended daily intake of biotin is 30 micrograms per day, according to the American National Institutes of Health (NIH), and we naturally hit that mark through our diets — most healthy adults get about 35 to 70 mcg per day, Woodson says. Some biotin-rich foods include meat (and organ meats), fish, eggs, nuts, seeds, and sweet potatoes.
Benefits of biotin
Benefits of biotin (vitamin B7)
- Glucose: Biotin helps to process carbohydrates (glucose), fats, and proteins and convert them into energy for the body to use, says Marisa Garshick, a dermatologist at MDCS Dermatology in New York.
- Fatty acids: Biotin is necessary for the creation of fatty acids, which are essential for cell maintenance and energy storage, says Stacey Woodson, a registered dietitian.
- Amino acids: Biotin helps deconstruct amino acids, a.k.a. the building blocks of proteins. Amino acids are repurposed to create energy or support other metabolic needs, says Woodson.
Benefits of biotin supplements
- Hair growth: For people who have thinning hair because of a biotin deficiency, some studies suggest that biotin supplementation can reduce hair loss and stimulate hair regrowth. “Most people typically see significant improvements after consistent use for three months or longer,” Woodson says.
- Nail and cuticle health: Supplementing with biotin may help strengthen weak nails, as some studies show taking 2.5 mg per day can help with nail thickness. But the evidence isn’t crystal clear. The studies out there on using biotin for brittle nails are very small, and the researchers didn’t use placebo groups or check participants’ initial levels of biotin.
What is the downside of taking biotin?
Some people report mild digestive symptoms, like an upset stomach, when taking biotin supplements. Yet even in high doses, there isn’t any evidence that suggests biotin supplements are harmful or toxic, Woodson says. That’s because biotin is water-soluble and the excess gets excreted through urine, so it doesn’t build up in the body at toxic levels.
Still, you may not be in the clear, at least not on paper. Biotin may interfere with certain laboratory test results including thyroid and troponin levels (a marker used to detect heart attacks), according to the FDA. If you’re getting lab tests done, make sure to stop taking biotin beforehand and always remember to tell your doctor about all medications, including supplements (as well as multivitamins), you’re taking, Dr. Garshick says.
How much biotin should you take for hair growth?
Research shows that taking 5,000 mcg (5 mg) of biotin daily may help treat hair loss caused by a biotin deficiency. But remember, a biotin deficiency is pretty rare. And there isn’t much scientific evidence that supports biotin supplementation significantly improving hair health for those of us without a biotin deficiency.
“Generally speaking, the only people who should absolutely be taking biotin supplements are those who are deficient, which is generally rare,” Dr. Garshick says. “That said, although there isn’t much clinical evidence, if people are looking to try something for their hair and nails, they can consider it and if they are noticing an improvement, it is fine to continue with it.”
Dr. Garshick recommends Thorne’s biotin supplement because it contains a high dose of 8,000 mcg. The instructions suggest taking up to two capsules a day but one easy-to-swallow pill gives you more than enough of your daily biotin dose (30 mcg per day). We like that Thorne is also rigorously tested—each supplement batch goes through four rounds of in-house testing to make sure the purity and potency are up to par.
One GLAMOUR reviewer who has been taking the Thorne biotin supplement for six months says the main thing she’s noticed is how much softer and stronger her strands are. “I’ve heard of some people seeing an increase in baby hairs around the hairline, but for me, I’ve seen that my hair, which I’ve been highlighting blonde for over a decade, is stronger (no breakage), softer, and growing longer and faster,” she says. “For the first time in years I actually had to book a haircut in between normal visits because it was getting so long so fast.”
- Type: Capsule
- Dose: 8,000 mcg (8 mg)
- Pros: Free of dairy, soy, and gluten; one capsule serving size; rigorously tested
- Cons: A bit pricier than other brands
Solgar’s biotin supplement offers 5,000 mcg of biotin. Unlike some extra-strength supplements, which can contain double the biotin dosage, this pick from Solgar packs in a moderate amount of B7 so you can start slow and customise your dosage based on your results. The lower dosage also means you’re less likely to get side effects like an upset stomach.
What’s more, “this formulation also contains calcium and phosphorus, so it’s the ideal choice for those looking for more than a simple biotin supplement,” Woodson says. Plus, it’s gluten-free, vegan-friendly, and dairy-free, and comes in a dark glass bottle that protects the pills from oxidising.
- Type: Capsule
- Dose: 5,000 mcg (5 mg)
- Pros: Lower dosage is more customisable; contains added calcium and phosphorus
- Cons: Not for those who want a simple biotin supplement
Now’s Extra Strength Biotin is non-GMO, vegan-friendly, and made with quality ingredients you can trust. “It’s free from artificial sulfites and it’s CGMP [Current Good Manufacturing Practices] certified, meaning it meets requirements set by the FDA, and exhaustively tested for quality, purity, and potency in Now’s third-party accredited ISO [International Organisation for Standardisation] labs,” says Lauren Manaker, a dietitian. Just one easy-to-take capsule provides a large dosage of 10,000 mcg of biotin.
One Amazon reviewer notes: “I’ve been taking these for months now, and I’ve absolutely seen a difference in my hair growth. After struggling with postpartum hair loss, I think these are definitely the way to go. The pills are a little big but no larger than other capsules. No odd tastes either.”
- Type: Capsule
- Dose: 10,000 mcg (10 mg)
- Pros: One capsule serving size; third-party-tested; vegan
- Cons: High dose may cause minor side effects
This supplement offers 2,500 mcg of biotin, a dosage that’s especially great for those new to taking biotin who want to start slow. Nature Made’s biotin comes recommended by experts because it’s a quality supplement that’s also affordable and widely available at most drugstores. “Nature Made is an excellent choice for a supplement as it bears the USP symbol, a third-party-verification seal that ensures quality products to consumers,” says Woodson.
Hundreds of reviewers note that these soft gels are small and very easy to swallow — just make sure to take them with a meal to avoid an upset tummy (a potential side effect associated with all biotin pills).
- Type: Softgel
- Dose: 2,500 mcg (2.5 mg)
- Pros: Easy to take; USP-verified; affordable and widely available
- Cons: Contains gelatin, so may not be suitable for certain diets
Pure Encapsulation’s supplement offers 8,000 mcg (8 mg) of biotin. The serving size is just one capsule, and reviewers note that the pill is small and goes down easily. We love that it’s free from common allergens and unnecessary dyes. “This is the ideal supplement for those with special dietary needs as this formula is gluten-free, vegan, and free from soy and dairy ingredients,” Woodson says. Plus, it’s tested for purity and potency by third-party labs.
One 54-year-old Amazon reviewer notes: “Starting this product again after many years not needing it; I last used it in 1999. My hair recently has been shedding a lot and this is my go-to product for bald spots.”
- Type: Capsule
- Dose: 8,000 mcg (8 mg)
- Pros: Serving size is one capsule; free from major allergens; third-party-tested
- Cons: High dose may cause minor side effects
More supplements content:
- Shop the best folic acid supplements for pregnancy
- Best cortisol supplements, as approved by experts
- Best NAD+ supplements to shop today
- Tried and tested pre-workout supplements, as reviewed by a fitness editor
- The best vitamin D supplements to take during winter
- The best lions mane supplements, as the hero ingredient trends on TikTok
- Magnesium supplements for better sleep
- Our pick of the best collagen supplements for better skin and hair
- Reviewed iron supplements for all-year-round
This story originally appeared on GLAMOUR US. After something else? Shop the best hair masks for hair growth, best shampoo, and best hair growth products.
.jpg)
