Do Hair-Growth Vitamins Work? 6 Supplements That Get Our Stamp of Approval

One Cosmo editor says: "I have such a hard time getting myself to take vitamins. It's a problem; my doctor hates me. Anyway! This one is actually easy because it's only two tiny pills per day. I keep it with my skincare, and ever since I started taking these, I'm calling my hairstylist for root touch-ups way more often the last few months."—BETH GILLETTE, BEAUTY EDITOR

To narrow down this list of best vitamins for hair growth, we consulted with the above dermatologists and trichologists on their own recommendations for patients. Then, we also dove deep into the ingredients of each treatment to determine which actually have ingredients that might encourage healthier scalp and hair. We've also thoroughly tested products on ourselves (including polling other Cosmo staffers) and combed through product reviews and ratings.

“While hair-growth vitamins may potentially help improve overall hair health, there is not enough evidence to prove their efficacy for hair growth,” says board-certified dermatologist Marisa Garshick, MD. In essence, hair-growth vitamins could work to help grow longer, thicker hair, but it's not that simple. If your hair loss or thinning is caused by a vitamin deficiency, then potentially flooding your body with a whole lot of that vitamin could, potentially, help slowly regrow back some hair. But “Most people get all the vitamins they need to manage their hair growth from their diet alone,” says Burg, meaning all that extra in your system won't do too much.

Some hair-growth supplements will contain botanical extracts, like grapeseed extract, saw palmetto, horsetail extract, and others—that are filled with amino and fatty acids that might help encourage scalp stimulation a bit. But there's just not enough scientific research yet that can say any of these truly work.Here's the thing: Vitamins and supplements are not FDA-approved, which means there isn't a universal standard when it comes to ingredients, strengths, or formulations. Plus, all of these concoctions can include a whole slew of ingredients that say they work, even when there isn't the scientific backing proving so just yet. Which brings us to...

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 (after all, 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, who specializes in hair loss. “The literature is sketchy at best, and most dermatologists agree that supplements are not very impressive.” Instead, your best bet is to talk to your doctor (seriously—their many 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.

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-vitamin-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 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 have a deficiency—you’ll usually end up peeing out the excess vitamins pretty soon after you ingest them.

So if you do decide to try any of the above hair-growth vitamins, expect to take them consistently for three to six months before you'll notice results. And really, it can take even longer—potentially, up to a year–if you're experiencing hair loss or thinning. Hair growth takes a lot of time—your hair only realistically grows ½-inch per month.

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 dermatologist Samantha Ellis, MD.

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.

Yes, 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.

Before you start shopping for hair-growth vitamins, it’s worth checking in with your doctor to talk through the specifics of your hair loss. A medical professional can help determine whether shedding is linked to stress, hormones, nutritional deficiencies, or an underlying health issue—and make sure your body is in a healthy place before you add supplements into the mix. Once you get the green light, they can recommend a plan tailored to your goals, whether that includes correcting a specific vitamin deficiency, adding a topical treatment like minoxidil, or considering prescription options such as oral spironolactone for hormonally driven hair loss. With that foundation in place, there are a few key factors dermatologists and nutrition experts say to keep in mind when choosing a hair-growth vitamin.

Look for clinically supported ingredients.

Biotin often gets the spotlight, but dermatologists also point to nutrients like zinc, iron, vitamin D, selenium, and the B‑complex vitamins as important players in healthy hair growth. Some formulas combine these with botanical boosters like saw palmetto or horsetail extract — though evidence for botanicals can be mixed, they’re worth discussing with your clinician.

Match the formula to your deficiency.

The most effective supplementation starts with knowing what you’re actually deficient in. For example, if your doctor confirms low iron or vitamin D, targeting that specific gap can make a bigger difference than a generic multivitamin.

Pay attention to form and dosage.

Not all supplements are created equal. Some vitamins come as single‑nutrient pills, others as multi‑ingredient blends; some are gummies, others capsules. Dosage matters, too — too much biotin, for example, can skew certain lab results and interfere with thyroid testing. That’s another reason to loop in your clinician before starting.

Consider your lifestyle and absorption.

Some ingredients are better absorbed with food or healthy fats, so your doctor or dietitian can help you sequence your routine (e.g., take with breakfast vs. at night) to maximize effectiveness.

If you’ve already stocked up on gummies or supplements — or have been taking them for a while — bring them along to your appointment. Your doctor can review the ingredients list, weigh the potential benefits for hair growth, and flag any possible interactions with medications or underlying conditions. Approaching hair‑growth vitamins with professional insight and personalized context means you’re investing in something that’s not just trendy, but genuinely tailored to your body and goals.

• 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.

Beth Gillette is the beauty editor at Cosmopolitan with seven 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.

Siena Gagliano was the associate editor at Cosmopolitan, and has four years of experience writing about beauty, fashion, and lifestyle news. She’s an expert at researching and writing beauty stories, like the best shampoo for a dry scalp and the best hair-growth oils, and feels especially knowledgeable in hair-growth vitamins, thanks to her own struggles with—what she believes—was post-Covid-19-related hair loss. She regularly tests and analyzes vitamins for her own hair for efficacy, while working with the industry’s top dermatologists and trichologists to assess new formulas and brands.

Additional reporting by Chloe Metzger, the former deputy beauty director at Cosmopolitan with 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.