

Try as we may, our diets, habits, and go-to shampoos and conditioners aren't always supporting our hair health as much as they could be. And while investing in hair growth shampoos, hair growth oils, and other top-notch topical hair growth products can go a long way in supporting scalp health and making your hair grow, it's paramount to focus on nutrition if you're looking to grow your longest, healthiest locks yet. And if your normal diet just isn't doing the trick, you may want to look into options like collagen powders and hair growth vitamins.
The supplement industry is a controversial one, being that it's not regulated by the Food and Drug Administration (FDA), but there are still plenty of vitamin manufacturers that run clinical trials on their products and employ doctors and, in the case of hair growth vitamins, board-certified dermatologists in order to monitor safety and efficacy. To learn more, we tapped Dr. Kim Nichols, a board-certified dermatologist and expert for Nutrafol, to understand what makes a hair growth vitamin safe and effective. Scroll on to learn more about the dos and don'ts of hair supplements, and to find the best hair growth vitamin for you, no matter your flavor preference, hair goal, or dietary restrictions.
What To Look For in a Hair Growth Vitamin
While there are a number of hair growth supplements on the market, each claiming to optimize hair growth, it's important to remember that not all vitamins are built alike. So, how do you know a high-quality hair growth vitamin when you see on?
"When seeking out a hair growth supplement, you want to consider clinically effective, medical-grade ingredients," advises Dr. Nichols. "The best ingredients for hair growth include B vitamins, vitamin D, vitamin E, vitamin C, zinc, and iron." In particular, she recommends biotin as one of the most helpful—not to mention the most popular—ingredients in supporting hair, skin, and nail health.
But while hair growth vitamins can go a long way in filling any nutritional deficiencies adversely impacting your hair health, it's important to note that they're not cure-alls. A healthy diet, water consumption, exercise, and responsible haircare (like not heat-treating or over-bleaching your hair) are the primary keys to supporting hair growth and retention.
Dr. Nichols also reminds us to trust science. "If you’re in the market for a new hair growth supplement be sure to do your research," she says. "It’s important to purchase products that are backed by science—meaning they are shown to be clinically effective." And although the FDA does not regulate the supplement industry, you can still check if your supplements have been clinically tested by researching online or simply checking the back of the bottle.
How Hair Growth Vitamins Work
For many, it's hard to believe that taking a pill or gummy can really make your hair grow longer. So, what's the purported science behind hair growth vitamins?
"Hair growth supplements work synergistically to strengthen your hair," Dr. Nichols explains. "Vitamin C, for instance, increases blood circulation to your scalp; stimulating your hair follicles encourages hair growth. Moreso, when your hair growth vitamin includes vitamin D, like Nutrafol, it is metabolized by cells in the epidermis that create keratin."
And keratin, she tells us, is the "structural and protective protein" that makes up much of our hair, skin, and nails. Thus, when you ingest nutrients that support the production of keratin, Dr. Nichols says you are "reinforcing this natural protein in your body."
What Are the Possible Side Effects of Hair Growth Vitamins?
It's important to be careful when consuming any supplement or non-prescribed treatment—no matter what it's for. And while supplements are, as mentioned, not regulated by the FDA, some truly are more rigorously tested than others.
For instance, Dr. Nichols says, "There have been studies that show high levels of vitamin A can be linked to weakening of hair follicles. This is only the case when over-supplementation is occurring. When you ingest too much vitamin A, it triggers your hair follicles to go into overdrive and overgrow hair that sheds quickly. This is why it’s important to take a supplement that’s shown to be clinically effective, as the optimum dosages per ingredient has been taken into consideration."
However, she notes that even if your chosen supplement does work, it can come with side effects. "Hair growth supplements can potentially cause additional hair growth for someone with hormonal disorders that cause excessive growth in facial and body hair," she says. Among the most common of these disorders is Polycystic Ovarian Syndrome (PCOS).
Some users also claim that hair growth vitamins cause their skin to "purge," or break out, more than usual. Dr. Nichols says, "There’s no solid evidence of hair growth supplements causing breakouts. However, some vitamins don’t always work well with one another. For instance, too many B vitamins, such as biotin, can lead to dehydration in the skin; this can eventually lead to breakouts. That’s why it’s incredibly important to read the ingredients and consult with your local board-certified dermatologist."
Finally, she mentions, "While we have no reason to believe they are unsafe, hair supplements are not usually tested in pregnant women."
Nervous, or unsure that hair growth supplements are right for you? Call your doctor! Dr. Nichols herself says, "I always suggest consulting with your healthcare provider prior to taking any sort of supplement."
- Best Overall Hair Growth Vitamin: Nutrafol Women Hair Growth Supplement for Thicker, Stronger Hair
- Best Thickening Hair Growth Vitamin: Viviscal Extra Strength Hair Growth Supplements
- Best Vegan Hair Growth Vitamin: Vegamour GRO Biotin Gummies for Thinning Hair
- Best-Tasting Hair Growth Vitamin: Hello Bello Hair, Skin, Nails + Collagen
- Best Hair Growth Vitamin for Shedding: Olly Heavenly Hair Gummy Supplement
- Best Hair Growth Vitamin for Hair Loss: Nioxin Recharging Complex Hair Growth Supplement
Best Hair Growth Vitamin Pills
"Nutrafol supplements target key factors of thinning hair such as nutrition, stress and lifestyle with natural, medical grade ingredients," says Dr. Nichols. "This clinically effective supplement improves hair growth and visible thickness."
Pros: clinically-tested; dermatologist-recommended; editor-approved (I've tried and loved this formula)
Cons: expensive; only a 30-day supply
Nioxin is beloved by dermatologists and trichologists for its hair thickening products. The Recharging Complex Hair Growth Supplements—packed with biotin, zinc, and iron—do not disappoint when it comes to strengthening your hair from the inside out. Customers rave that it's made a significant difference in treating hair thinning and baldness, whether from alopecia or age, for both women and men.
Pros: beloved by reviewers; clinically tested
Cons: some reviewers say it gave them acne
I personally swear by these pretty, metallic pink caplets. Three a day (there are 150 in this package) go a long way in maintaining healthy hair, skin, and nails. Plus, they've never given me acne or an upset stomach the way some other supplements do.
Pros: affordable; large supply
Cons: contains yeast, so not suitable for those allergic
Multiple reviewers rave that this supplement stopped their hair loss (in many cases from crash-dieting and poor nutrition) in its tracks and allowed their hair growth to resume at an impressive pace.
Pros: supports lash and brow growth; fills in nutrition gaps
Cons: expensive for only a 30-day supply
This supplement is a fan favorite, loved by hairstylists and celebrities (including Jen Aniston, subject of hair envy everywhere) because it actually works. These tablets are formulated with horsetail extract, fish protein, and vitamin C to strengthen strands, prevent split ends and speed up your growth process. They're also beloved by balding women and former chemotherapy recipients for their ability to promote complete hair regrowth.
Pros: helps strengthen existing hair; clinically tested
Cons: only work after consistent use for 3-6 months
This high-potency supplement not only promotes healthier and shinier hair with a slew of fatty acids, vitamins, and antioxidants, but it also makes your nails stronger and promotes glowing skin. Reviewers say that the regimen is easy to follow and that after a few months of use, they noticed a difference in hair growth and thickness.
Pros: includes a guided regimen on when to use and take a break; large quantity
Cons: requires prolonged use for results
Unfortunately, hair loss and thinning are often a result of stress, both physical and psychological. While practices such as meditation, good diet and sleep, and exercise help with this, you can also turn to supplements such as this one to boost your nutrition. Reviewers, many of whom dealt with personal and health-related stressors, say that Moon Juice's formula bolstered their hair growth, decreased loss, and improved density.
Pros: fights stress-related hair loss; improves both fullness and length
Cons: large pills; aftertaste
This drugstore favorite will keep your strands strong for two whole months at an unbeatable price. These pills are among my go-tos, and they last for ages. Plus, they're tiny, easy to swallow, and don't have an unpleasant aftertaste.
Pros: large quantity; affordable; include Vitamin C; easy to swallow; no aftertaste; gluten-free
Cons: not vegan (formula includes gelatin)
This supplement is formulated with biotin, resveratrol, and Cynatine HNS Keratine—an ingredient that helps improve damaged hair and skin. Thus, the formula can be used to both aid hair thinning and also to protect hair and skin from the wear and tear of sun damage, heat treatment, and styling. Several customers say that the capsules work effectively, but caution that patience is key.
Pros: easy to swallow; no aftertaste; combats hair thinning
Cons: relatively expensive for size of supply; results require prolonged use
Not only will this multivitamin help you reach your hair goals, but with the presence of vitamin A, D3, and E you'll also benefit from an enhanced immune system. Users attest to this, saying that the formula even helps with joint pain by augmenting collagen intake.
Pros: helps overall health; affordable
Cons: not vegan
Best Hair Growth Vitamin Gummies
I love this supplement from Kierr, which incorporates coconut oil and elderberry into its formula, but hones in on getting you your daily fill of biotin. "The most popular B vitamin, biotin, is a key player in promoting the growth of healthy hair," explains Dr. Nichols. "With biotin comes an increase in keratin production, which is the main component of your hair make up."
Pros: