Glamour April 29, 2024



10 Best Hair Growth Serums, According to Dermatologists


Say hello to your best hair ever.

There are many causes for hair loss or hair thinning—pregnancy, medication, stress, tight hair styling, or just plain genetics, to name a few. Some hair loss treatments are more intense than others, but scalp serums and certain hair oils are an easy topical place to start. These hair growth products help create an optimal scalp environment, promote hair growth, decrease hair loss, and strengthen individual strands. Of course, not all formulations are made equally, and not all serums effectively address hair health adequately. We spoke to dermatologists, trichologists, and hair stylists to find the best hair growth serums for stronger, healthier hair from root to tip.

All products featured on Glamour are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.

Best Overall: Rogaine Women’s 5% Minoxidil Foam

All our experts agree: Minoxidil is the gold standard when it comes to hair growth. In fact, it’s the only ingredient approved by the FDA to do so. But don’t just take their word for it; studies also show that this particular formula, which features a 5% concentration of the star ingredient, can boost hair growth. The unscented formula is easy to apply and a single box contains a two-month supply. While not the chicest option, this cinched the top spot for one simple reason: It simply works. And at the end of the day, there’s nothing more compelling than that.

Size: 2.11 oz / Dosage: Half a capful once daily / Key Ingredients: Minoxidil 5% / Cruelty-Free: No

What we like: Evidence-based claims, effective
What could be improved: Packaging is fairly lackluster

Best for Fine Hair: Kérastase Initialiste Strengthening & Volumizing Advanced Scalp & Hair Serum

Board-certified dermatologist Teresa Song, MD, suggests this serum for people with fine hair and oily scalps, thanks to its lightweight texture and strand-strengthening formula. “I like that it has ceramides to help hydrate and moisturize hair,” says Jodi LoGerfo, MD, a doctor of nursing practice and family nurse practitioner certified in family medicine and dermatology. “It also contains green tea as an antioxidant and a UV filter to protect hair against sun damage.” Meanwhile, Sanda Petrut, a stylist at Maxine Salon in Chicago, says the trifecta of ingredients is great for those with weaker hairlines looking to thicken fine hair, particularly around the face.

Size: 2.2 oz / Dosage: Apply 2 pipettes for fine hair or 4 pipettes for normal to thick hair, three times a week / Key Ingredients: Ceramides, green tea extract, SP94 / Cruelty-Free: No

What we like: Thickens and strengthens fine, weaker strands
What could be improved: We’d love a cruelty-free option

Best for Curly Hair: Pattern Argan Oil Hair Serum

A blend of argan, apricot, and sunflower oils, the Pattern Argan Oil Hair Serum promotes hair strength and health by keeping strands moisturized. According to Dr. LoGerfo, the hydrating formula helps with dry hair and scalp, creating an optimal environment for hair growth. It keeps curl cuticles soft and smooth without leaving behind any of that dreaded residue that can come with other oil blends. Plus, the serum is sulfate- and silicone-free, making it ideal for those precious curls.

Size: 3.9 oz / Dosage: A few drops daily / Key Ingredients: Argan oil, apricot oil, sunflower seed oil / Cruelty-Free: Yes

What we like: Residue-free formula leaves curls moisturized but bouncy
What could be improved: Oil-heavy formula isn’t great for thinner hair or oily scalps.

Best for Oily Scalps: Philip Kingsley Density Preserving Scalp Drops

Applying any sort of product to an oily scalp can feel like a losing battle—eight times out of ten, it simply makes things worse. Luckily, these Density Preserving Scalp Drops are in the minority, actively reducing excess sebum and deterring hair loss. According to Dr. Song, peroxide and zinc work to minimize scalp oil while ingredients like peptides, saw palmettos, and caffeine work to improve hair density. In fact, Dr. LoGerfo notes several studies have recognized caffeine as a hair-growth stimulant, praising its ability to prevent hair loss and improve hair quality.

Size: 5.07 oz / Dosage: Apply in one-inch sections to clean, washed hair / Key Ingredients: Piroctone olamine, menthol, adaptogens, synthetic botanical blend / Cruelty-Free: Yes

What we like: Residue-free formula is ideal for oily scalps
What could be improved: Focuses more on hair density versus hair growth

Best for Dry Scalps: Mielle Rosemary Mint Scalp & Hair Strengthening Oil

The TikTok-famous Rosemary Mint Scalp & Hair Strengthening Oil features more than 30 essential oils and nutrients, several of which are clinically proven to support hair growth, Dr. Song says. The gentle oil formula is ideal for more sensitive, dry scalps that might benefit from additional hydration and nourishment. The rosemary oil is infused with biotin, which is a vitamin linked to hair growth (though clinical research has been inconclusive). The formula works on two fronts to create an optimal environment for hair growth while actively strengthening existing hair to decrease hair loss.

Size: 2 oz / Dosage: Apply a small amount to scalp daily / Key Ingredients: Biotin, rosemary leaf oil, mint oil / Cruelty-Free: Yes

What we like: Formula features essential oils clinically proven to support hair growth
What could be improved: Might be too moisturizing or heavy for oilier scalps and thinner hair

Best for Damaged Hair: Evolh Better Roots RootBoost Serum

Powered by 10 clinically proven active ingredients, trichologist Shab Caspara counts this among her favorite hair growth serums, thanks to its ability to stimulate hair follicles and support healthy hair regrowth. By working to maintain the scalp’s microbiome and support protein and melanin synthesis (the processes inside hair follicles that control hair growth and color), the serum spurs the scalp’s growth cycle, resulting in thicker, fuller hair. The oil-free blend is fast absorbing and virtually weightless, with a vegan, gluten-free, and soy-free formula that works with virtually any hair type or scalp concern. Within that formula is a host of hardworking plant-based ingredients: Swiss apple stem cells help delay hair-follicle deterioration; copper tripeptides promote a healthy hair life cycle and strengthen hair follicles; pea sprout extract has a positive effect on hair gene expression; and mushroom beta glucan supports collagen production and hydrates the scalp.

Size: 1 oz / Dosage: Apply one to two times daily, starting with â…“ of a dropper and adding as needed / Key Ingredients: Swiss apple stem cells, copper tripeptide, pea sprout extract, mushroom beta glucan, Alpine rose stem cells / Cruelty-Free: Yes

What we like: Focuses on scalp health as well as hair growth
What could be improved: The added fragrance could be irritating for particularly sensitive scalps

Best for Frizzy Hair: K18 Molecular Repair Hair Oil

K18 Molecular Repair Hair Oil works on two levels of the hair fiber to fight frizz, strengthen strands, and repair damage, all of which help to promote a healthy environment for hair growth. On the surface, natural oils like avocado and sunflower oils and squalane nourish the hair, Dr. Song explains, while the brand’s proprietary K18 peptide addresses deeper level damage within the innermost layer of the hair fiber. According to Dr. LoGerfo, this helps hair withstand the everyday assaults we put it through, making strands more resilient and stronger. It also enhances shine and color vibrancy, and provides heat protection up to 450°F.

Size: 1 oz / Dosage: Apply to damp or dry hair as preferred, starting with one to three drops / Key Ingredients: K18 peptide, hemisqualane, squalane, avocado oil / Cruelty-Free: Yes

What we like: Offers additional heat protection and aesthetic improvements to the hair
What could be improved: Oil formula isn’t ideal for all scalp types, particularly oily scalps

Best for Shedding Hair: The Ordinary Multi-Peptide Serum for Hair Density

Board-certified dermatologist and founder of Facet Dermatology, Geeta Yadav, MD, is a fan of this affordable option, particularly calling out the many protein-building amino acids and three lab-made complexes on the ingredient list. Those complexes, procapil, redensyl, and baicapil, all work to promote thicker, stronger hair by targeting stem cells and human fibroblasts and increasing blood flow in the scalp, Dr. Song explains. The concentrated formula also features caffeine to improve hair density and uses a lightweight, emollient base for efficient scalp penetration.

Size: 2 oz / Dosage: Apply a few drops to clean scalp daily / Key Ingredients: Redensyl, procapil, baicapil / Cruelty-Free: Yes

What we like: Reasonable price makes it far more accessible than other options
What could be improved: Can feel slightly sticky

Best for Thinning Hair: Vegamour GRO Hair Serum for Thinning Hair

This serum uses plant-based active ingredients to reduce hair shedding and fallout. Dr. Yadav points to DHT-blocking clover extract, regenerative glycoproteins, and strengthening peptides as star ingredients, though caffeine and turmeric are also standouts, helping to stimulate the scalp and increase the appearance of hair density.

Size: 1 oz / Dosage: Apply one full dropper to scalp daily / Key Ingredients: Turmeric, caffeine, red clover and mung bean blend / Cruelty-Free: Yes

What we like: It leaves hair feeling stronger and more resilient
What could be improved: Added fragrance may irritate especially sensitive scalps

Best for Aging Scalps: Évolis Reverse Activator

Évolis’ Reverse Activor hair serum utilizes a patented formula to address brittle, thinning hair and reduce age-related hair loss. According to Caspara, a plant-based blend accelerates hair growth and extends the hair cycle, while keratin and wheat protein help strengthen and fortify individual strands for visibly thicker, more resilient hair. Meanwhile, natural antioxidants and nutrients maintain scalp health to create that optimal environment for hair growth and health. By treating the hair from root to tip, the serum addresses age-related hair loss and thinning holistically for maximum results.

Size: 1.7 oz / Dosage: Apply one full dropper to scalp twice daily / Key Ingredients: Keratin, wheat protein, FGF 5 / Cruelty-Free: Yes

What we like: Thin, watery consistency doesn’t weigh down strands
What could be improved: Twice daily application can be hard to stick to

What ingredients should I look for in a hair growth serum?

When looking for hair growth serums, it's important to look for products containing ingredients that have scientific evidence in promoting hair growth. “Minoxidil is FDA approved to promote hair growth by increasing blood flow to the scalp, and essential oils like rosemary and peppermint oil have been shown in clinical studies to stimulate hair growth comparable to low concentration minoxidil,” Dr. Song says. Meanwhile, Dr. Yadav suggests looking for ingredients that support the growth of healthy hair by fostering a healthy environment for the hair follicles such as aminexil, caffeine, and ceramides. She also points to rosemary oil, clover extract, and saw palmetto extract, which help block DHT, a hormone connected to hair loss—though she notes the evidence here isn’t as robust as others. Dr. LoGerfo recommends ingredients that increase hair density and volume like biotin, amino acids, omega fatty acids, niacinamide, peptides, keratin, and hyaluronic acid.

How do I know if a hair growth serum is “working”?

Remember that it takes time and commitment to determine if any product is working, especially a hair growth product. Because the rate at which hair grows is around half an inch per month, Caspara says it can be difficult to measure the effectiveness of a hair growth topical in less than three months. If you’re consistent, you should start to see new growth around that time period—according to Dr. Yadav, you should see hairs sprouting up along the hairline or at the top of the scalp. Depending on the type of hair serum, by three months you can also expect decreased hair fall, lengthening of once-shorter baby hairs, and stronger, shiner hair strands.