Dealing with Hair Thinning? Experts Swear By These 11 Top Growth Serums
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Thinning and loss are major reasons to invest in one of the best hair growth serums, especially after realizing your ponytail feels a little lighter than usual. But contrary to what some beauty lovers may believe, hair doesn't need to show visible signs of thinning to incorporate one of the best hair growth serums into your routine.
"You lose approximately 80 to 100 hairs a day," Julie Dickson , founder of Joon Drop Hair Salon, tells Bazaar . "Hair growth serums, after nutrition, are the first line of defense in slowing fallout and encouraging growth. If you're waiting for visible signs of thinning before you start addressing hair loss, it's a little late."
Our Top Picks:
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Best for Sensitive Scalps: Nutrafol Women's Hair Serum
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Best for Density: Vegamour Gro Hair Serum for Thinning Hair
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Best Under $25: Undefined Beauty R&R Scalp Serum
Generally, hair loss is a physiological response to stress, shifting hormones, genetics, or illness, and it affects women in every age bracket. Fortunately, today's best hair growth serums for thicker hair—and the growing category of hair growth devices —don't just promise volume; they're backed by dermatologists, powered by clinical ingredients, and designed to treat the scalp as seriously as the skin.
We asked leading dermatologists to break down the most effective formulas and the ingredients worth paying attention to. Whether you're dealing with shedding , postpartum changes , or the slow, frustrating creep of genetic thinning, we've pulled together the best hair growth serums to shop now that deliver real, measurable results.
Nutrafol Women's Hair Serum
This non-greasy serum is designed to deliver visibly thicker, stronger hair in 90 days by replenishing key nutrients directly at the scalp. "It includes plant-based DHT blockers and peptides and is good for sensitive scalps," says dermatologist Kseniya Kobets , who often recommends it to patients experiencing early signs of hair loss or inflammation.
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Key ingredients:Ashwagandha exosomes, Irish moss peptides, pea sprout extract
Vegamour Gro Hair Serum for Thinning Hair
Powered by Redensyl, a plant-based active known to support hair density and reduce shedding, this serum is a go-to for thinning. "It's another good option," adds Kobets. "It's vegan, fragrance-free, and formulated with Redensyl, making it effective for early thinning." For more intensive hair thinning and fall-out, Vegamour also offers an advanced version of its beloved serum.
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Key ingredients:Turmeric, caffeine, red clover, mung bean blend
Nécessaire Rosemary Serum
Fans of Nécessaire's coveted Rosemary shampoo and conditioner should consider adding its plant-based, quick-drying serum to their hair care regimen. Its hypoallergenic formula is not only EU-compliant but also dermatologist-tested to enhance hair density and strength while reducing thinning over time.
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Key ingredients:Rosemary water, rosemary oil, rosemary extract, capixyl, proteins, ceramides
Cécred Restoring Hair & Edge Drops
These Beyoncé-approved hair and edge drops are among her brand's top-selling products for good reason—they work. The formula combines a proprietary blend of peptides with strengthening ingredients, including fermented rice powder, biotin, and Cécred's keratin ferment, to increase scalp density and overall hair health. And, nicely, the drops can even be used with wigs, extensions, and more.
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Key ingredients:Biopeptide-5, bioactive keratin ferment, fermented rice powder, biotin, rose extract, ginger extract
Undefined Beauty R&R Scalp Serum
This calming serum takes a wellness-first approach to scalp care, combining adaptogens, botanicals, and CBD to soothe inflammation and support a healthier environment for hair growth. Designed for stressed-out scalps, the serum helps reduce flakiness and balance oil production without clogging follicles.
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Key ingredients:Niacinamide, plant peptides, saw palmetto
Seen Restore Scalp Serum
Formulated for even the most reactive skin types, this lightweight, fragrance-free serum delivers gentle scalp support, which helps encourage hair growth. Free of sulfates, silicones, and common allergens, it's ideal for those who've struggled to find a product that won't trigger redness or sensitivity. "For patients with highly sensitive or allergy-prone skin, this has been clinically tested for common allergens and may be a calming choice," notes Kobets.
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Key ingredients:Ethylhexyl olivate, squalane, propanediol caprylate, sarcosine
Aunt Jackie's Curls & Coils Batana, Jojoba & Rice Elixir Hair and Scalp Oil
This nutrient-rich elixir is formulated to nourish the scalp and support healthier, stronger hair from root to tip. Batana oil, often referred to as "liquid gold" in some Afro-Caribbean communities, is known for its ability to help restore thinning edges and promote the appearance of thicker, fuller hair.
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Key ingredients:Batana, jojoba, and rice bran oils
KeraFactor Scalp Stimulating Solution
Developed by dermatologist Amy Taub, the formula in this growth solution uses synthetic biomimetic growth factors, designed to mimic the body's natural signaling proteins. It also contains nanoliposomes to deliver them deep into the scalp. "It's backed by science and used in-office and at home, which makes it a trusted option for both prevention and regrowth," says dermatologist Teresa Song .
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Key ingredients:Biomimetic growth factors, skin proteins, nanofluorosomes
RevitaLash Volume Enhancing Foam
While not exactly a serum, this scalp conditioning foam is dermatologist-approved to help stimulate hair growth. Originally known for its lash-boosting formulas, this lightweight foam from Revitalash is especially well-suited for anyone looking to boost volume. "This foam contains peptides and is especially helpful postpartum or when seeking added volume without irritation," explains Kobets.
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Key ingredients:BioPeptin complex, saw palmetto, ginseng, swertia japonica, amino acids, vitamin B
Hårklinikken Hair Gain Extract
This extract applies directly to the scalp, offering a non-greasy treatment Dickson says won't weigh down strands and therefore won't make the issue worse as it's being treated. It strengthens at the roots to stimulate regrowth, "so you're not weighing down already-fine hair or sacrificing volume," Dickson says. Hårklinikken also offers a highly personalized approach with a Hair Assessment that helps customers tailor their Extract's formulation to their specific scalp profile.
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Key ingredients:burdock root, marigold, apple, sandalwood, cow's milk, tannins, and fatty acids found in botanicals
Kerativ Redensify Treatment Serum
This dermatologist-developed product is backed by a ton of science and testing. For starters, dermatologist Kristen Lo Sicco highlights how the formula "brings together complementary ingredients targeting the appearance of hair density and overall scalp health while still being lightweight enough for everyday use." She says the serum also underwent an independent six-month-long study that showed "statistically significant improvement in hair density and volume beginning at three months."
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Key ingredients:Redensyl 3%, Kopexil 1%, TrichoCore Complex, Adapinoid, Panthenol, Ectoin
FAQs
Meet the Experts:
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Teresa Song is a dermatologist based in New York City.
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Kseniya Kobets is a dermatologist based in New York.
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Kristen Lo Sicco is a dermatologist based in New York and associate professor of dermatology at NYU Langone Health.
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Julie Dickson is a fine hair specialist and the founder of Joon Drop Hair Salon.
What Contributes to Hair Loss?
Hair thinning can show up gradually or all at once, and it's rarely caused by a single factor. "Hair thinning in women is surprisingly common and can happen for a mix of reasons," says Song. "Hormones, stress, nutritional deficiencies, and genetics all play a role."
For many, a sudden shift such as postpartum recovery or chronic stress) can trigger telogen effluvium, a condition in which a large number of hairs prematurely enter the shedding phase. Others experience a more insidious form of thinning known as androgenetic alopecia, where hair follicles become increasingly sensitive to normal hormone levels, shrinking over time and producing finer, weaker strands. "The scalp is incredibly responsive to what's going on inside the body," Song adds.
Fellow dermatologist Kseniya Kobets echoes this: "Hair loss is often multifactorial and rarely due to a single isolated cause," she explains. She frequently sees patients with androgenetic alopecia that's been triggered or worsened by another form of hair loss, like telogen effluvium or traction alopecia.
Is There a Difference Between Hair Loss and Shedding?
It's important to distinguish between shedding and true thinning, as the two require different approaches. "Shedding is when you're losing more hair than usual, but the follicles are still healthy and capable of regrowth," notes Song.
You might see extra strands in your brush or clogging the drain, especially after a stressful period or big life change. Thinning, on the other hand, is more structural. The follicle begins producing smaller, finer hairs (or none at all), leading to visible changes in density.
"Hair thinning refers to a reduction in overall hair density or strand diameter, even if the number of hairs falling out isn't increased," notes Kobets. You might notice your ponytail feels thinner, or that your scalp is more visible through your part.
What Hair Growth Ingredients Should I Look For?
In a category crowded with overhyped claims, only a few ingredients have real clinical evidence behind them. Minoxidil remains the gold standard. "It increases blood flow and prolongs the anagen, or growth, phase of the hair cycle," says Kobets.
Other promising ingredients include caffeine, rosemary oil, and pumpkin seed oil—all of which may enhance circulation and have mild DHT-blocking effects. Peptides, licorice root, and even peppermint extract are also showing potential in early studies. "Peppermint has demonstrated a hair growth effect in animal models, potentially upregulating growth factors," notes Song.
What these ingredients have in common is their ability to support scalp health, reduce inflammation, and extend the growth cycle, all of which contribute to stronger, thicker hair over time.
When Should I Expect Results from the Best Hair Growth Serums?
Hair doesn't follow instant gratification timelines. According to experts, early signs like reduced shedding may show up around the three-month mark, but visible regrowth typically takes closer to six months or longer. "Hair follicles need time to cycle through their growth phases, and new hairs must grow long enough to become visible," she says. Song emphasizes consistency: "Most people start to notice changes in texture or reduced shedding in two to three months, but fuller results usually take six months or more."
Does Hair Texture Impact What Serum You Should Buy?
It's generally good to purchase a serum with a formula that complements your curl pattern. "Oils are better used on curlier hair given it is more prone to desiccation [drying]," Lo Sicco says. "Someone with straighter hair may find an oil more difficult to maintain use over time if it causes the hair to become greasier quicker." She adds that lightweight, non-greasy serums that directly apply to the scalp are especially best for fine or easily weighed-down hair, while those with dry or sensitive scalps should prioritize using formulas featuring hydrating and barrier-supporting ingredients.
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