IT'S GIVING GROWTH

3 Best Scalp Serums That Support Fuller-Looking Hair

Nurturing your follicles can bring you one step closer to thicker, healthier hair.
Image contains a photo of an Allure editor surrounded by scalp serums that promote hair growth.
Collage: Gabrielle Langdon; Source images: Courtesy of Allure editors and brands

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The best scalp serums for hair growth might sound too good to be true. Formulated to create a healthier environment for strands to grow, these lightweight treatments are meant to reduce inflammation, balance oil production, and support follicle function over time. But, before we dive in, it's worth managing expectations: If you're experiencing thinning hair and active hair loss, it's important to consult your dermatologist. There could be any number of contributing factors—hormonal imbalances, genetics, underlying health conditions, and recurring tension, to name a few—that a topical simply can't fix.

With that said, if you have modest goals of encouraging hair growth and thickness, hair-growth serums can help, and we spoke with dermatologists to put their favorite ones to the test. Ahead, find the scalp serums that make hair feel fuller, promote hair growth, minimize shedding, and improve overall scalp health.

Our Top Scalp Serums

Best Overall: Nécessaire The Scalp Serum

Nécessaire The Scalp Serum in branded component on a light gray background

Nécessaire

The Scalp Serum

Allure content director Kara McGrath using Nécessaire's The Scalp Serum

Kara McGrath

Why it’s worth it: If your hair goals include less shedding and more fullness, Nécessaire The Scalp Serum might be worth adding to your routine. This daily, lightweight scalp treatment is designed to create a healthier scalp environment that supports thicker-looking hair over time. Central to the formula is Capixyl, which combines red clover extract with acetyl tetrapeptide-3. “There are some small-scale studies comparing it with minoxidil that show it has similar results in terms of boosting hair growth,” says Chicago-based dermatologist Omer Ibrahim, MD. (Minoxidil is a widely used topical treatment that helps extend the hair’s growth phase by increasing blood flow to the follicles.) “Capixyl helps reduce inflammation and shedding while stimulating hair proliferation,” he adds. The formula also includes niacinamide, which “can help support hair health by slowing shedding and providing antioxidant protection,” he says. And, if you have a sensitive scalp, it’s also been recognized by the National Eczema Association as proof of just how gentle and skin-friendly the formula is.

Kara McGrath before and after using Necessaire's The Scalp Serum for 4 months.

Kara McGrath

Tester feedback from content director Kara McGrath

“Working it into my hair-care routine was easy. The formula goes on super wet and dries really quickly. It played well with my other products—leave-in conditioners, curl creams, dry shampoo, too. I applied it to wet hair on washdays and dry hair the rest of the week. It didn’t leave a trace in either situation. Other than sticking to the recommended ‘half pipette’ amount of product, my application technique was fairly haphazard. I would part my hair with my fingers and use the dropper to apply the serum directly to my scalp in different sections, then massage it in. I started seeing results pretty quickly. After about a month, my hair was already looking much shinier and bouncier, if not exponentially thicker.” —Kara McGrath, content director

Kara has type 2 wavy hair, thinning hair, and has been using Nécessaire The Scalp Serum for five months.

How the brand tested this product’s efficacy

Nécessaire says you’ll start seeing results from The Scalp Serum after 90 days, which lines up with the average eight-to-12-week hair growth cycle. And according to the brand’s own clinical data, 90% of people saw thicker hair and 94% saw fuller hair after using the serum (along with its shampoo and conditioner) for three months. The formula takes a skin-care-first approach “to treat scalp with the same care and advanced ingredients as facial skin,” says Brattleboro, Vermont-based cosmetic chemist Sherry Backman.

Hyaluronic acid counteracts dryness and itchy scalp, which can reduce the kind of low-grade inflammation that silently disrupts healthy growth. capixyl—a blend of a peptide and red clover extract—helps anchor hair more securely and blocks DHT, the hormone that causes follicles to shrink and shed. Niacinamide, a form of vitamin B3, calms irritation, reduces oxidative stress, and helps prevent DHT-triggered hair-shedding signals. “All of these effects support healthier follicles and steady growth,” says Backman.

More to know

  • Key ingredients: capixyl, hyaluronic acid, biotin, niacinamide
  • Fragrance-free: yes

Best for Textured Hair: Cécred Restoring Hair & Edge Drops

Cécred Restoring Hair & Edge Drops silver dropper bottle on light gray background

Cécred

Restoring Hair & Edge Drops

Allure Editor in chief Jessica Cruel applying Cécred Restoring Hair & Edge Drop

Jessica Cruel

Why it’s worth it: Beyoncé’s editor-loved Cécred Restoring Hair & Edge Drops keep selling out, and our testers understand why. This fast-absorbing, non-greasy serum is designed to help strengthen thinning areas and boost hair density, especially around the hairline. According to Dr. Ibrahim, “of the featured ingredients, peptides have the most promising evidence to help stimulate hair growth, but it depends on what kind of peptides are used.” Brattleboro, Vermont-based cosmetic chemist Sherry Backman agrees, noting that the real heavy hitters in this formula are the peptides, “which can influence follicular signaling, anagen phase duration, and follicle anchoring.” She adds that some of the biomimetic peptides in this product “may even help ‘wake up’ dormant stem cells in the follicle,” potentially encouraging thicker, denser hair over time.

While biotin and keratin are unlikely to regrow hair when applied topically, they can “help reinforce the hair shaft and reduce breakage,” which can improve the look of fullness, says Backman. The formula also includes ginger extract and fermented rice proteins—ingredients with early, though limited, evidence suggesting they may support scalp health. Add in a subtle sandalwood-musk scent and a cooling feel from peppermint oil, and you’ve got a routine-worthy favorite.

Tester feedback from editor in chief Jessica Cruel

“A year ago I started to notice how my edges seemed to snap with even the slightest slick back. So, I put away the edge brush and picked up these Cécred Restoring Hair & Edge Drops. I'm on my second bottle! It feels like a serum, not so watery that my natural hair reverts but not too oily either. The smell is divine and after months of using it, I feel my hairline has become more resilient.” —Jessica Cruel, editor in chief

Jessica has type 4B hair, an itchy scalp with hair breakage, and has been using Cécred Restoring Hair & Edge Drops at least five days a week for several months.

How the brand tested this product’s efficacy

Cécred conducted a 16-week third-party study on participants with visibly thinning edges. The results showed up to a 1.5x improvement in hair density when used daily, along with noticeable improvements in hair texture and scalp health. It also showed that 84% of participants agreed they saw their edges and hairline return, 84% reported visibly improved hair density, and 84% noticed better overall scalp and hair health. While individual results may vary, the brand’s clinical testing suggests consistent use can lead to stronger, fuller-looking edges over time.

More to know

  • Key ingredients: bioactive keratin ferment, biopeptide-5, biotin, fermented rice powder, ginger extract, rose extract
  • Fragrance-free: no

Best for Sensitive Scalps: Vegamour Gro Hair Serum

Vegamour GRO Hair Serum pink and gold serum dropper bottle on light gray background

Vegamour

GRO Hair Serum

Allure shopping market editor Angela Trakoshis applying Vegamour Gro Hair Serum

Angela Trakoshis

Why it’s worth it: If your scalp’s been getting in the way of healthy hair growth, this daily reset might be for you. Vegamour Gro Hair Serum “uses plant-based ingredients like red clover and mung bean to stimulate hair follicles, boost density, and reduce shedding,” says Margarita Lolis, MD, a board-certified dermatologist and Mohs surgeon based in Hackensack, New Jersey. “It’s ideal for those experiencing thinning hair and has strong clinical evidence backing its claims.” The serum also includes caffeine and peptides to support healthy circulation and minimize fallout at the root. “On top of that, the serum is clean, lightweight, and safe for all scalp types—even sensitive scalps.” It absorbs quickly with zero residue, making it easy to use daily, and has earned a loyal following (they boast the top spot as a prestige hair serum for thinning and shedding).

Angela Trakoshis before and after applying Vegamour Gro Hair Serum

Angela Trakoshis

Tester feedback from shopping market editor Angela Trakoshis

“I’m on my second bottle of Vegamour’s Gro Hair Serum and the baby hairs are finally coming in—just in time for my wedding. It’s the only growth serum I’ve tried that doesn’t leave my roots greasy, just fuller.” —Angela Trakoshis

Angela has type 2B wavy hair, oily scalp concerns, and has been using Vegamour GRO Hair Serum two to three times a week for five months.

How the brand tested this product’s efficacy

In clinical and placebo-controlled studies, 93% of users reported reduced shedding, 90% noticed an improvement in the appearance of their hair, and 83% stated that their strands felt stronger and more resilient. Visible results can be seen in as little as 90 days, with up to an 85% reduction in signs of shedding and a 56% increase in hair density.

More to know

  • Key ingredients: turmeric, caffeine, mung bean, and red clover blend
  • Fragrance-free: yes

More scalp serums to consider:

  • If you have hereditary hair loss, Rogaine 5% Minoxidil Foam is ideal for individuals who are noticing gradual shedding and want to slow down the process or regrow some of what has been lost. This Best of Beauty Award winner is one of the few over-the-counter treatments with clinically proven hair regrowth claims. “It’s FDA-approved, well-studied, and widely available,” says Backman. Initially created as an oral medication to help manage high blood pressure, minoxidil was later discovered to promote hair growth as a beneficial side effect. leading to the development of topical formulas. “Though its exact mechanism isn’t fully understood, it’s believed to extend the hair growth cycle and enhance follicle function by boosting blood flow and cellular activity,” says Backman. Consistency is key, though: It only works as long as you keep using it.
  • If you're looking for a gentle scalp care approach or are experiencing early signs of thinning, Act+Acre Cold Processed Stem Cell Scalp Serum helps create a healthy growth environment. “The serum contains apple-derived stem cells, which deliver signals to enhance the activity of the hair follicles themselves,” says New York City-based board-certified dermatologist Joshua Zeichner, MD. The formula also includes hyaluronic acid to hydrate and protect the scalp, as well as bio-fermented minerals and amino acids to nourish the follicles—all cold-processed to preserve potency without harsh chemicals.

Frequently Asked Questions

What’s the best ingredient for hair regrowth?

The best ingredient for hair regrowth is minoxidil, which dermatologist Dr. Ibrahim calls “the gold standard for hair regrowth.” It's FDA-approved and works by increasing blood flow to the hair follicles and extending the growth phase. “But it can be a little harsh and lead to dry scalps,” he adds, which is why oral minoxidil has been gaining popularity as a gentler alternative.

You can read more about minoxidil in our reporting on what dermatologists say you can really expect from the hair loss treatment here.

For those seeking alternative options, Dr. Ibrahim notes that ingredients such as caffeine, peptides, niacinamide, ginseng extract, and rosemary oil show promise in reducing shedding to make hair look fuller. He also mentions that naturally sourced DHT blockers, such as saw palmetto, could be helpful for hair loss caused by hormonal factors.

How long does it take to see results from a scalp serum?

Most hair products take time to deliver noticeable results, and scalp serums are no exception. “Even with minoxidil, it usually takes three to six months to see any visible hair growth,” says Dr. Ibrahim. “For scalp serums without minoxidil, I recommend using them for at least six months.” Since hair grows in cycles, visible improvements in density won’t happen overnight. Many of these hair products work gradually by reducing shedding and improving overall scalp health first. The key is consistency: apply regularly and give your follicles the time they need to respond.

Are there any risks to scalp serums?

Scalp serums are generally safe; however, certain ingredients may cause irritation, particularly for individuals with sensitive skin or pre-existing scalp conditions. “Stimulating actives like caffeine, menthol, essential oils (e.g., rosemary, peppermint), or even niacinamide can cause irritation, redness, or itching in sensitive individuals,” says Backman. She also notes that overusing DHT-blocking botanicals may impact hormone-sensitive users. To minimize risks, it’s best to patch test first and avoid applying serums to broken or inflamed skin. Those with scalp eczema, psoriasis, or seborrheic dermatitis should check with a dermatologist before using formulas with strong stimulants.

Meet the experts

How we test and review products

When Allure tests a product, our editors look at it from every angle in an effort to best serve you. We review ingredients, scrutinize brand claims, and, when necessary, examine peer-reviewed scientific and medical studies. In addition to testing each and every product that's included in each and every review, we rely on experts who shape their fields, including dermatology, cosmetic chemistry, and medicine, to help us vet the ingredients and formulas.

For our list of the best scalp serums for hair growth, we considered each product's performance across the following categories: product ingredients, packaging, fragrance, texture, and efficacy. Every product was determined to have excelled in each category by our editorial team, which is composed of in-house writers and editors as well as contributors—along with special consideration from dermatologists. For this piece, our editorial testers are those who are specifically looking for overall fullness and hair thickening, and tested the products for a minimum of four months. To learn more information on our reporting and testing processes, read our complete reviews process and methodology page.

Our staff and testers

A beauty product is a personal purchase. You might be searching for a face cream to address persistent dryness or a new nail product to add to your Sunday self-care routine; you may simply be browsing around for the latest launches to hit the hair market. No matter what you seek or your individual needs and concerns, Allure wants to ensure that you love anything we recommend in our stories. We believe that having a diverse team of writers and editors—in addition to the wide range of outside testers and industry experts we regularly call upon—is essential to reaching that goal.

After all, can we really say a skin-care product is the "best" for people over 50 if the only testers we've solicited opinions from folks who have yet to hit 30? Can we honestly deem a high-end diffuser worthy of your hard-earned cash if it's never been tested on curls? We're proud that our staff spans a wide range of ages, skin tones, hair textures, genders, and backgrounds, which means that we are able to fairly assess any beauty product that comes into the beauty closet.


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