Credit: Act+ Acre
Key Ingredient: Apple stem cells | Size: 2.2 fl oz.
This do-it-all scalp serum is Shape writer Maddie Barber’s holy grail product — she hasn’t gone a night without applying it to her scalp (whether she’s at home or traveling) since she received her first bottle in the mail five months ago. “As someone who struggles with persistent scalp patchiness due to trichotillomania [a condition that causes obsessive hair pulling], my fuller hairline and part and sprouting of newfound baby hairs everywhere speak for themselves,” she says. “This stuff really works and, thankfully, never leaves any residue behind.”
Act + Acre’s Stem Cell Scalp Serum focuses on improving your scalp’s overall health to, in turn, stimulate hair growth and produce a thicker mane. Utilizing the power of two percent apple stem cells, this serum aims to reinvigorate hair follicles to produce growth in any necessary areas, resulting in satisfying regrowth (and minimal shedding!) for all hair types. A bonus? This formula also includes aloe vera and hyaluronic acid to hydrate the scalp and reduce any itchiness or irritation from dryness.
While Act + Acre notes it takes up to 90 days to notice a total transformation, you can observe an objectively healthier, nourished scalp after just one month, setting the stage for more growth later on. Be sure to apply one to two pipettes worth of serum on clean, damp or dry hair, gently rub it into your scalp, and let it absorb (don’t rinse it out).
Credit: Amazon
Why We Like It
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Great value at only $10
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Active ingredients include rosemary, ginseng, and caffeine
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Lightweight and non-greasy
Key Ingredient: Rosemary oil, caffeine, ginseng | Size: 2 fl oz.
The Grow Long Hair and Scalp Serum from Marc Anthony is a tester-approved, budget-friendly option with rosemary, ginseng, and caffeine — ingredients that work wonders for hair growth. When wrapped in this lightweight serum and massaged into a damp or dry scalp, rosemary can effectively improve the state of your hair follicles to lead to stronger, longer strands; ginseng can prevent shedding; and caffeine can promote further growth.
Thankfully, this formula doesn’t leave your hair greasy, so you can apply it and head out the door with no problem or before bed without needing to wash your pillow afterward. Plus, the $10 price tag ensures you can use this up without worrying about breaking the bank.
Credit: Amazon
Key Ingredient: Minoxidil | Size: 2.1 oz.
According to Howard Sobel, M.D., minoxidil is the only FDA-approved ingredient for growing new hair and the gold standard for many dermatologists and hair experts. With this, Shape’s team of testers knew they had to test Women’s Rogaine 5% Minoxidil Unscented Foam, which features minoxidil as its primary active ingredient and can regrow up to 25 percent more hair.
The application process is simple and straightforward, albeit slightly messy, since you must massage a capful into the scalp. Once on, the product took about 15 minutes to absorb into the scalp, making it a quick, convenient part of testers’ nighttime routines. Even without rinsing it out, the product didn’t leave any residue on the testers’ strands or feel like it weighed their hair down, nor did they experience any tingling or irritation.
While it can take months to see full results, testers did notice growth and an overall improvement in fullness during testing. The lightweight foam was easy to use daily; just keep in mind that you’ll have to keep up with the application to see consistent improvement. Consider a hair-growth supplement like Nutrafol for additional assistance in growing fuller, healthier hair.
Credit: Kerastase
Key Ingredient: SP94 and ceramides | Size: 2.2 oz.
After testing Kerastase’s Initialiste Scalp & Hair Serum, Shape editors immediately understood why it’s a fan-favorite. First and foremost, the lightweight, watery serum was easy to apply thanks to the dropper applicator, requiring just three full droppers to adequately cover the scalp. After six weeks of nightly use, the formula provided impressive results in the density department, and testers noticed a few patchier areas of their scalps sprouting new strands.
The absence of minoxidil in this formula is one of the main aspects setting this serum apart, instead including the brand’s signature SP94, which Kerastase says “reinforces hair structure and strength through the lengths,” strengthening ceramides, smoothing and softening conditioners, and antioxidant-rich green tea extract. It’s worth noting that this serum was not as hydrating as testers would have liked, so if you struggle with dry strands, it may help to add a nourishing conditioner to your routine, like the brand’s Nutritive Lait Vital Conditioner.
Credit: Ulta
Key Ingredients: Rosemary extract, biotin, argan oil, jojoba oil, castor oil | Size: 2 oz
Rosemary oil and rosemary shampoo are the top natural remedies for aiding hair growth, and this option from Kitsch is an editor favorite. The hero ingredient, rosemary, also reduces the effects of an itchy, irritated, and dry scalp, whether that results from sweating, product buildup, or a condition as significant as dandruff. The inclusion of argan, jojoba, and castor oils work together to nourish the scalp and further assist those struggling with irritation. You can score this serum (which comes in the cutest pink bottle) at under $20 — a steal compared to other options on the market.
Credit: Philip Kingsley
Why We Like It
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Notably reduces hair shedding
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Makes hair look and feel thicker
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Lightweight serum doesn’t leave a residue
Key Ingredients: Biomimetic Peptide Blend, azelaic acid, pyridoxine HCL, saw palmetto, and zinc PCA | Size: 2.87 oz.
The Philip Kingsley Density Preserving Scalp Drops for Hair Loss prevent excess shedding rather than focusing solely on restoring new growth. Formulated with the brand’s Biomimetic Peptide Blend, described as “an innovative and unique active complex designed to reduce hair shedding and improve hair density and quality over time,” this cooling hair serum is meant to be applied daily for best results, leading to a less visible scalp and more conditioned strands.
When trying the formula, testers were fond of the plastic dropper, which made applying the watery serum to the scalp a breeze. While the brand recommends using two and a half milliliters of the product daily, you can use less if you have ultra-fine hair to prevent weighing it down. After six weeks, testers found their hair looked impressively thicker and brush bristles less plagued with hair post-brushing. The lightweight, virtually fragrance-free serum left no pesky residue on their strands, either — a pleasant surprise.
Credit: Amazon
Key Ingredient: Biotin, caffeine, rosemary extract | Size: 1 fl oz.
The BosleyMD Follicle Energizer is a powerhouse serum that relies on a litany of different ingredients to improve the look and feel of your strands. “Protective botanical extracts make for thicker, fuller-looking hair, biotin strengthens, while rosemary extract helps to reduce scalp inflammation and increase circulation,” says trichologist Gretchen Friese, who advises using it on targeted areas rather than all over. “With this product, I like to tell people, ‘If you want hair, put it there.’”
For best results, the Follicle Energizer must be applied to freshly shampooed scalps up to twice daily. While the brand doesn’t directly state how long it takes to notice fuller-looking strands, considering the ingredients at play, you can expect to use it for at least a couple of months for a notable difference in the length and fullness of your strands.
Credit: Sephora
Key Ingredient: Peptides, red clover flower extract | Size: 2 fl oz
If you’ve noticed that areas around your hairline are thinning more than usual, consider this scalp serum from Ouai. Editors love the peptides in this formula, which are known to work wonders for stimulating hair growth (one study shows that certain types can even function better than minoxidil) and make the treated areas appear much fuller. This serum also utilizes the effects of red clover flower extract and Arctic Root, Siberian Ginseng, And Chaga Mushroom to improve overall scalp health, creating a more favorable environment for hair growth.
The application process is easy. Just remember that daily use is required for the best results — simply apply a pipette’s worth of serum to your hairline and part and massage into your scalp each day.
Credit: Sephora
Why We Like It
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Supports fuller, healthier-looking hair
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Refreshing rosemary scent
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Lightweight formula
Key Ingredient: Rosemary oil | Size: 3.3 oz.
Hoping for impressively thicker hair? The Nue Co. Supa Thick Scalp Serum can do the trick. When testing this serum (applying it two to three times a week for six weeks), testers found that their hairline appeared fuller and their heads of hair more voluminous. Despite its liquid-y consistency, the testers were pleased that this formula didn’t weigh their strands down or lead to a stringy, greasy-looking appearance post-application. Plus, its refreshing rosemary scent was a breath of fresh air, making for a self-care treat each and every time they applied it to their scalp. Just keep in mind that the rosemary extract also touts a tingling sensation that, while some can find it invigorating, others may find irritating.
Credit: Sephora
Key Ingredient: Turmeric and caffeine | Size: 1 fl oz.
There’s a reason shoppers swoon over the Vegamour GRO Hair Serum. “This serum can visibly increase hair density up to 50 percent while reducing loss from combing and washing by up to 76 percent in four months,” says Friese. This is thanks to several unique ingredients not found in many other hair growth serums, namely, mung bean and red clover, which have been shown to help inhibit the production of dihydrotestosterone (DHT, a hormone that plays a role in hair loss), and nicotiana benthamiana, an Australian plant whose proteins have been shown to increase the density of hair roots, she explains.
You can read one former Shape editor’s review, which includes her two-year experience with the serum and her results. Spoiler: “I’m a happy customer — and now a Vegamour subscriber, to boot (which also lets me save money on every bottle),” Alyssa Sparacino reveals in her review. “And these days, I can confidently wear my hair in a ponytail without staring at my scalp peeking through.”
Credit: Briogeo
Key Ingredient: Biotin, caffeine | Size: 1.5 oz.
Testers were wowed by Briogeo’s fast-acting Destined for Density MegaStrength+ Peptide Density Serum formula during testing. Infused with biotin and caffeine to stimulate follicles and enhance hair growth, it was no surprise that significant new growth and fullness sprouted at the hairline — one of the main target areas while testing — though it’s worth mentioning that it didn’t do much in terms of total length. However, when it comes to volume and density, this serum is a win.
At first glance, this orange-tinted treatment seems like it would be thick and greasy, though testers found it to be delightfully lightweight, even for fine hair. It took about 30 seconds to adequately sink into the scalps (whether using it on dirty or clean hair), making it particularly convenient to use during busy mornings and nights.
Credit: Amazon
Key Ingredient: Castor oil, peppermint oil, olive fruit oil, coconut oil, and rice bran oil | Size: 2 fl oz.
Castor oil is another common ingredient in hair growth formulations due to its antimicrobial and antifungal abilities. By helping reduce impurities and dandruff on the scalp, it’s easier for new hair to grow, and editors are happy with the inclusion of this ingredient in RED By Kiss’ Growth MD Hair and Scalp Oil. Not only this, but the formula also includes peppermint oil, olive fruit oil, coconut oil, and rice bran oil, to name a few, to further assist with hydrating, strengthening, and replenishing the hair.
Our testers love the ease of use of this oil. To apply, simply give the bottle a few good shakes, twist up the cap, and direct the serum to the areas on your scalp experiencing hair loss (and don’t rinse it out!). It’s important to apply this serum daily for the most noticeable results.
Credit: Augustinus Bader
Key Ingredient: Baobab, argan, and pomegranate oils | Size: 1 oz.
If you have oily hair, you need The Hair Oil in your life. This sunflower seed oil-based hair serum conditions and strengthens strands, reducing shedding and hair loss.
When testing this oil, testers found applying this serum two to three times a week super straightforward, thanks to the included dropper. They targeted the mid-shafts and ends of their hair, noticing instantly smoother-looking strands sans greasiness or residue. Despite not applying the potent product directly to their scalp, they were surprised to notice slight hair growth by the end of the testing period. While the growth wasn’t major, the shine, softness, and overall quality of their hair most definitely was. By the six-week mark, they were met with softer, fuller, more hydrated, easier-to-style strands that didn’t look nearly as stringy or weighed down by greasy roots. So, if you’ve been fiending for healthier-looking, less oily hair, make room for The Hair Oil in your routine.
Credit: Amazon
Key Ingredient: Biotin and keratin | Size: 1.69 oz.
Viviscal Hair Thickening Serum is the perfect treatment for those desiring a more voluminous mane. Formulated with biotin and keratin, the serum is designed to trigger new hair growth while strengthening and maintaining current strands. When testing this serum, testers first admired the seamless application process — all it takes is pumping the thin, watery formula directly onto your palms and massaging it from mid-shaft to your ends. Yes, this is another hair serum designed for applying to the lower half of your hair, yet it still notably enhances the health, fullness, and appearance of hair from roots to ends.
While testers immediately noticed fuller-looking hair with this serum, they didn’t experience any additional growth that can be attributed to the product alone. Still, the fact that the product isn’t irritating and doesn’t leave behind a greasy residue, and is affordable makes it a winner in Shape’s book.
Credit: Sephora
Key Ingredient: Amino acids, amaranth peptides | Size: 1.7 oz.
Hair loss is a common concern for those growing older, and Living Proof’s Scalp Density Serum provides the perfect two-in-one treatment for anyone over 50 looking for relief. This formula not only boasts thickening abilities with the brand’s signature Density Boosting Technology, which not only aids with hair growth but also prevents shedding from happening in the first place and can diminish the look of graying hair. That’s right, this serum’s Anti-Gray Complex includes a blend of antioxidants and amino acids that work together to limit gray hairs on your head, both in preventative and reactive ways. Anyone experiencing aging in the scalp and with their strands will find that this serum truly does it all.
Credit: SickScience
Why We Like It
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Unique, science-backed ingredients
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Targets growth, density, and hair strengthening
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Derm-tested
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Hypoallergenic
Key Ingredients: NX35 Growth Technology | Size: 60 ml
Packed in this futuristic-looking bottle is SickScience’s powerhouse hair growth serum with an innovative formula, boasting the use of its patented NX35 Growth Technology. In simpler terms, this serum works by sending messages to your cells to “correct cellular activity,” as the brand says, to kick your scalp into the anagen phase (the growth phase of the hair growth cycle) and catalyze new hair growth, improve density, and strengthen strands.
Shape loves how it’s dermatologist-tested and hypoallergenic, so despite all of the fancy features, you know, at the end of the day, it won’t irritate the scalp. As with all hair growth serums, be sure to use this consistently (once a day on damp or dry hair) for the best results, and keep in mind that your first bottle is suitable for a two-month period.
What to Know About Hair Growth Serums
- Ingredients to Look For: Only one ingredient, minoxidil, is FDA-approved to grow new hair, Sobel says. Try plant-based options for more preventative measures and to help ward off thinning in the first place; rosemary extract, CBD, curcumin, and Procapil (a botanical alternative to Minoxidil) are a few key ingredients to seek out.
- Ingredients to Avoid: If you’re suffering from hair loss, there are some ingredients you might want to steer clear of in your hair-care products. “Alcohol can dry out your hair, leading to breakage and hair loss,” explains Jeannette Graf, M.D., a board-certified dermatologist and assistant clinical professor of dermatology at Mount Sinai School of Medicine in New York. “Silicones can clog the hair follicles, and formaldehyde can contribute to hair loss and dry out your scalp, too.” Two other ingredients Dr. Graf suggests trying to avoid are parabens and sulfate. “Parabens should be avoided as they might affect hair loss and have negative effects on the scalp,” she explains. “Sulfates can strip the hair’s natural oils and potentially dry out your hair.”
Frequently Asked Questions
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How do hair growth serums work?
“Over-the-counter hair growth serums stimulate hair regrowth by improving blood flow to each follicle and providing key nutrients such as biotin and essential vitamins,” says Dr. Austin. “Some formulations also help reduce scalp inflammation and provide a healthy environment for hair growth. It is essential to be consistent with serum application, and it may take several weeks to months to notice significant hair growth.”
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How do you apply hair growth serums?
You’ll want to refer to the package instructions, as not all formulas are applied similarly. However, the strategy is generally as follows: After washing hair, towel it dry, then create several parts down your scalp and dab, spritz, or use a dropper to deposit the formula along the part lines. Massage the serum or treatment into your scalp with your fingertips, then dry and style your hair as usual. Most serums are applied a few times per week; it can be easiest to keep track if you apply on your hair wash days. It can take up to 12 weeks to see results, so stay patient and consistent.
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What causes hair loss or thinning?
“Genetics play the most significant role in the condition of one’s hair, especially if there is a family history of hair thinning or conditions such as alopecia,” says Dr. Austin. “Seborrheic dermatitis, also known as dandruff, can cause scalp and hair follicle inflammation, causing hair thinning. Hormonal changes or imbalances, such as menopause or thyroid conditions, can also cause hair to thin. Medical conditions such as autoimmune alopecia areata can cause significant hair loss.” Aside from genetics, Dr. Austin explains other factors like nutritional deficiencies in essential vitamins, such as iron, biotin, and vitamin D, recent physical or emotional stressors such as giving birth, illnesses, surgery, and overall life stress (which specifically causes sudden hair loss phenomenon called telogen effluvium, says Dr. Austin), medications such as chemotherapy can cause severe hair loss or even balding, certain hairstyles like tight braids/locs, or chemical treatments such as coloring or straightening can cause hair loss.”
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What are natural ways to restore hair loss?
“Identifying the cause of hair loss is highly important. With bloodwork, it is relatively easy to identify nutritional deficiencies, which can be supplemented,” says Dr. Austin. “One of the most common causes of hair thinning is low iron, biotin, or vitamin D, so over-the-counter oral supplementation can be highly beneficial and sometimes curative.” Zinc and selenium sulfide can reduce yeast and dandruff, says the expert.
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How can I prevent hair loss?
Dr. Austin explains that derms can help you examine your family history, perform a physical exam, do bloodwork, and possibly perform a scalp biopsy to determine any preventable cause of hair thinning.
Why Trust Shape
Madison Barber is a Shape writer and beauty fanatic. She updated this article in 2024 after spending hours researching the best hair growth serums and treatments on the market and ensuring previous product picks are up to Shape standards.
The Shape team spoke with the following dermatologists and hair experts to inform this story:
- Howard Sobel, M.D., attending dermatologic surgeon at Lenox Hill Hospital and the founder of Sobel Skin
- Jeannette Graf, M.D., a board-certified dermatologist and assistant clinical professor of dermatology at Mount Sinai School of Medicine in New York
- Gretchen Friese, a trichologist for BosleyMD, a company that specializes in hair loss and restoration
- Bridgette Hill, a trichologist and colorist at the Paul Labreque Salon
- Dr. Andrea Austin, board-certified dermatologist
