When my hair started thinning at 25, thanks to a mix of stress, hormones, and chemical damage, I was looking for legit anything to help my hair grow faster. Hair-growth shampoos that promised thicker, fuller hair? Stocked my shower with ‘em. TikToks that boasted the miracles of castor-oil treatments, aloe-vera massages, and rosemary-oil products? I tried—and failed—every single one. So when my mom recommended hair-growth vitamins that supposedly make your hair grow longer and faster, I was intrigued… and also highly skeptical.

“While hair-growth vitamins may potentially help improve overall hair health,” says board-certified dermatologist Marisa Garshick, MD, “there is not enough evidence to prove their efficacy for hair growth.” I know, I’m sorry. And before you read that and think, “whatever—how risky can hair-growth supplements really be?” I’ve got news for you: Pretty freakin’ risky in the wrong person (more on that below). Which is why I chatted with five experts and doctors on the safety of hair gummies, whether or not hair-growth vitamins can grow your hair, what vitamins help with hair growth, and methods they actually approve of for hair growth.

✔️ FYI: We updated this article in March 2023 to give you the most up-to-date info on hair-growth vitamins, including new tried-and-tested formulas, a dermatologist’s take on hair-growth ingredients, and how to choose a hair-growth vitamin for yourself.

How do vitamins for hair growth work?

Usually, hair-growth vitamins, gummies, and supplements are filled with a mix of “hair-friendly” ingredients like biotin; folic acid; vitamins D, A, C, and E; and omegas, all of which supposedly work together to make your hair look longer, healthier, shinier, and stronger after a few months. That is, supposedly (yes, we’ll get into it). But first…

Are hair-growth vitamins safe?

Whether or not hair-growth vitamins are safe depends on your current health and the type of supplement or gummy you ingest. The thing is, supplements and vitamins are not FDA-regulated, meaning brands can kinda say and do whatever they want—and also add whatever mix of ingredients they want to their formulas. That’s not to say all gummies and vitamins are automatically scary and unsafe (afterall, it is bad business practice to poison customers), but because hair supplements aren’t backed by government-approved data, the research around them is either nonexistent or highly suspect.

“A lot of the studies you find in support of hair supplements are actually funded by the brands themselves,” says dermatologist Dhaval G. Bhanusali, MD. Dr. Bhanusali, who specializes in hair loss, says “the literature is sketchy at best, and most dermatologists agree that supplements are not very impressive.” Instead, your best bet is talking to your doctor (seriously—their 10+ years of schooling made them pretty smart in the hair-growth department), or trying some topical products instead:

But if you’re determined to try hair gummies, pills, supplements, and vitamins, regardless of what I say, then let me at least help you do it safely. So let’s get into what you really want to know:

Do vitamins for hair growth really work?

Important reminder: Vitamins and supplements are not FDA-approved, which means there isn’t a universal standard when it comes to ingredients, strengths, or formulations. So that means there’s never going to be an official yes or no answer as to whether vitamins for hair growth really work. But if you ask the experts—or me, who tried taking them for two months and was only left with breakouts—the answer to whether or not hair vitamins really work is pretty much a big ol’ NOPE across the board.

Plus, even though vitamins themselves are absolutely necessary and beneficial for your hair, they won’t do much if your body is already stocked with them—which it probably already is. “Most people get all the vitamins they need to manage their hair growth from their diet alone,” says trichologist Dominic Burg, chief scientist at Evolis Professional.

Does biotin help hair growth?

Unfortunately, there isn’t a definitive answer on whether biotin really helps hair growth, and every dermatologist we spoke with was on the skeptical side. According to dermatologist Vivian Bucay, MD,, if you’re taking a stand-alone biotin supplement, you’d need to take at least 5 milligrams daily for it to have a chance of affecting hair growth—but even then, there’s no guarantee it’ll do anything, she says.

It’s also worth noting that biotin—just like any supplement—isn’t without its downsides: Excess biotin has the potential to trigger breakouts in some acne-prone individuals (which is what happened to me). More research is needed to understand the exact correlation, but what is known is that taking biotin can also affect major medical tests your doctor may perform. So, as we’ll repeat again and again, make sure to discuss all supplement-related info with an actual doctor before trying any.

Are there side effects to vitamins for hair growth?

I know what you’re thinking: What’s the harm in taking hair growth vitamins and supplements, just in case they do end up helping? But sadly, that’s not how vitamins work in a healthy (read: non-deficient) human. Even if you were to ingest triple the vitamins your body needs (please don’t), you still wouldn’t reap triple, or even double, the hair growth rewards.

Why? Because “your body keeps only the vitamins it needs and then gets rid of the rest,” says trichologist Dominic Burg. It’s kind of like pouring water into a glass that’s already 100 percent full. So unless you’re actually missing some key nutrients—i.e., your doctor has confirmed you are vitamin deficient—you’ll usually end up peeing out the excess vitamins pretty soon after you ingest them.

What vitamin deficiency causes hair loss?

There isn’t just one vitamin deficiency that causes hair loss—thinning and shedding hair can actually be caused by multiple physical and mental factors. “There are a lot of women running around who are deficient and don’t realize it, either because of dieting, poor nutrition, or intense stress,” says Burg. And when you’re super stressed or not eating enough, “your body will shut down your hair growth first and redirect nutrients and energy to the organs that need it most,” he says, thus leaving you vitamin deficient and your hair growth at a standstill.

And if you’ve ever experienced a severe bout of physical or emotional stress (see: the pandemic), you might have noticed a sudden shedding of your hair a few months afterward. “It’s a delayed reaction to the stress or diet that usually occurs three months later,” says Burg. Of course, the only way to know for sure if your body is deficient is to have your levels tested by your doctor, so please wait for a physician to tell you supplements are safe for you to try.

Do any vitamins help with hair growth?

If your doctor confirms you’re vitamin-deficient, certain vitamins could potentially help with hair growth, says Dr. Bhanusali. “There are some studies and anecdotal evidence that support the idea that low vitamin D levels can hinder hair growth,” says Dr. Bhanusali, “and a lot of people tend to have low vitamin D, even if they’re otherwise healthy.” And the same goes for lower iron levels. “Many derms see good results by prescribing patients iron supplements and vitamin D supplements,” he says, “although always check with your doctor before taking anything.”

If you are not vitamin deficient (which, again, only a doctor can tell you) but still want longer, healthier, stronger hair, then sadly, “supplements will probably do very little for you,” says Burg. Hey, maybe you’ll be the lucky wild card—again, there are no mass studies definitively saying yes or no—but if we’re talking from a point of science here, your odds aren’t great.

What helps stimulate hair growth?

Ah, yes, the question you should be asking: If not supplements, then what? Luckily, you’ve got a ton of options:

Minoxidil

Minoxidil is the active ingredient found in both topical products (like Rogaine and Hers) that you massage on your scalp daily, and in oral medications that are prescribed by a doctor. “We don’t know the exact mechanism for how minoxidil works, but we think a lot of it has to do with increasing blood flow to the scalp,” says Dr. Bhanusali. “It’s like giving more water to the plant to help it grow.” Essentially, minoxidil helps encourage your hair to stay in the growth phase longer (versus the rest or shedding phase), which can increase hair density, says dermatologist Samantha Ellis, MD.

If you’re going to try topical minoxidil, just know you need to be consistent—use it every single day until…forever. And if you’re dealing with irritation or you’re not seeing results after a few months, head to your derm for prescription options (more on that below).

Steroids

If your hair loss is rapid—i.e., you’re suddenly shedding a ton of hair—versus gradual, there’s usually an underlying cause that should be addressed by a doctor or dermatologist ASAP (whether that’s stress, hormones, deficiencies, inflammation, or illness). Topical steroids or steroid injections are often used as a short-term fix to help get the shedding under control, says. Dr. Bhanusali.

Spironolactone

Yup, the magical acne-clearing pill can also be helpful for hair growth. “Oral spironolactone is a prescription blood-pressure medication that helps block androgens—male sex hormones—in females, which can help increase hair growth over time,” says Dr. Bhanusali. Another (off-label) added bonus? “Many patients find that their breakouts disappear and their hair is less oily too,” he says.

PRP therapy

PRP therapy—platelet-rich plasma therapy—is a treatment in which a doctor draws your blood, separates the plasma from it, then reinjects it into your scalp to help stimulate follicle activity. At least four sessions are usually required, and it’s not cheap (think: $600 to $1,200 per treatment), but it’s a promising option for hair growth. “I do think PRP can work in the right patient, but it’s not a guarantee,” says Dr. Bhanusali. “Studies generally show 20 percent of people get a significant improvement, 20 percent get slim to no results, and, anecdotally, the other 40 percent get maybe a 10 percent to 15 percent improvement.”

Compounded topicals

Thanks to the recent rise of skincare compounding (i.e., when your dermatologist custom-cocktails skincare formulas specifically for your face—think: Curology, SkinMedicinals, and Apostrophe,)we’re now seeing new compounding options for your scalp too, the latest of which being HairStim. “Your derm evaluates your scalp and then will pick and choose whatever ingredients they think will help with hair growth,” says Dr. Bhanusali, “like higher-dose minoxidil, retinoic acid, finasteride, topical spiro, salicylic acid—whatever makes the most sense for the patient.”

And unlike other hair supplements or prescription products that doctors can sometimes get a kickback for recommending (yes, that’s what really happens), “doctors don’t get a cent for recommending HairStim,” says Dr. Bhanusali, who actually created the company. The only potential downside? Compound topicals aren’t usually covered by insurance, including HairStim, which costs about $60 and lasts between 30 and 60 days, depending on how much you’re applying and how big the “affected” area is, like just your hairline or your entire head.

“We usually see results between 10 and 12 weeks,” says Dr. Bhanusali. I’ve personally used HairStim for my own thinning part for an entire year, and it’s the only formula that doesn’t leave my scalp dry, itchy, and irritated—solely because my dermatologist changed up the percentages and added additional skin soothers to minimize inflammation.

Medicated scalp treatments

Sounds obvious, but hair growth requires a peaceful environment to be successful. So if your scalp is irritated, inflamed, and flaky, whether due to dandruff, dry scalp, psoriasis, or eczema, you’ll need to re-establish a healthy foundation asap—which is where medicated scalp treatments come in.

If you’re working with a flaky, itchy scalp from dandruff, dermatologist Samantha Ellis, MD, recommends sudsing up with a dandruff shampoo with antifungals ingredients, like pyrithione zinc, ketoconazole, or selenium sulfide, all of which help to “reduce inflammation that leads to hair loss over time,” she says. If your shampoo isn’t helping after 3-4 weeks, head to the dermatologist for proper diagnosis and/or prescription treatments.

Is there a way to make your hair look thicker?

To make your hair look thicker, look to volumizing formulas (shampoos and conditioners, mousse, sprays, and creams), along with colored powders that visually conceal thinning. Because, even if you try the above treatments, you won’t see results overnight. But you can incorporate a hair-thickening treatment, like one with polymers that swell up your hair strands and make them look fuller, as well as starches that soak up oils that can weigh your hair down and make it look flat. You could also try a colored powder—like a scalp foundation or tinted hair fibers—to actually fill in the sparse areas around your hairline and make them look fuller.

Can a dermatologist help with hair growth?

Yes, a dermatologist can definitely help with hair growth and loss. “If your hair loss is abrupt and without an identifiable trigger, your scalp is itchy or painful, or if your hair loss or thinning is accompanied by other symptoms, then a trip to the doctor would be especially warranted,” says Dr. Ellis.

But even if you’re not dealing with other symptoms, you’d still be wise to see your dermatologist so they can do a full blood-panel workup to test for any vitamin deficiencies that could be contributing to hair loss or stunted hair growth. Then, they can make suggestions based on your age, sex, and other health conditions, including prescription options like oral minoxidil, finasteride, or spironolactone, along with in-office treatments like PRP therapy.

How to choose the best vitamins for hair growth:

Before trying to choose the best vitamins for hair growth, check in with your doctor to discuss your hair-loss specifics so they can first confirm your health status. After giving you the green light, they can then make recommendations on how to speed up your hair-growth journey, whether that’s taking a vitamin that you’re deficient in, starting topical minoxidil, or incorporating a prescription oral medication like spironolactone.

And if you already bought some gummies or supplements—and/or have even been taking them—make sure to bring them to your doctor’s appointment to get their thoughts on the ingredients list and how it could potentially benefit (or harm) both your health and hair growth.

Final thoughts:

Unfortunately, hair-growth vitamins don’t show any evidence of being able to magically grow your hair longer (only genetics, hormones, and age can do that). In fact, vitamins and supplements aren’t even regulated by the FDA, meaning brands have a lot of good-or-bad freedom in their ingredient formulations and marketing claims. So before you order a bottle of vitamins, set up an appointment with your doctor to discuss your hair goals and come up with a plan that can actually lead to longer, thicker hair.

Meet the experts:

• Marisa Garshick, MD, is a board-certified dermatologist at MCDS Dermatology in New York, NY. She is also a clinical assistant professor at Weill Cornell Medicine.
• Samantha Ellis, MD, is a board-certified dermatologist in Danville, CA. She’s also a clinical instructor of dermatology at the University of California Davis.
• Dhaval G. Bhanusali, MD, is a board-certified dermatologist and founder of Hudson Dermatology and Laser Surgery in New York, NY. Dr. Bhanusali is also the founder of HairStim, a custom-compounded hair loss formula that’s created and prescribed by your own dermatologist.
• Dominic Burg is a certified trichologist and chief scientist at Evolis Professional.
• Vivian Bucay, MD, is a board-certified dermatologist and founder of Bucay Center for Dermatology and Aesthetic in San Antonio, TX. Dr. Bucay is also a clinical assistant professor at the UT Health Science Center San Antonio.

Why trust Cosmopolitan?

Beth Gillette is the beauty editor at Cosmopolitan with four years of experience researching, writing, and editing hair stories that range from scalp acne shampoos to deep conditioners. She’s an authority in all hair categories but is an expert when it comes to hair-growth vitamins, thanks to interviewing dermatologists and doctors about how they work and which are actually worth trying.

Chloe Metzger is the deputy beauty director at Cosmopolitan with nearly 10 years of experience researching, writing, and editing skin, makeup, hair, and nail stories across print and digital, including curly hair products and clarifying shampoos. Her hair-growth vitamin picks were based on product reviews, ratings, and personal testing, along with information from experts.