The 14 Best Hair Growth Serums for Fuller, Thicker Hair, Tested by Our Editors

Real-life tested and expert-approved formulas for thicker, fuller hair.

We independently evaluate all recommended products and services. If you click on links we provide, we may receive compensation. Learn more.

A person dispensing hair growth serum into hand, next to bottles of other products and a brush

Health / Joy Kim

About 80 percent of men and 50 percent of women battle hair loss during their lifetime, and many of us invest a significant amount of time and money fighting it. While there's no magic potion, hair serums can help promote growth and thickness for some.

Hair growth serums enrich the scalp with nutrients, activate blood vessels to oxygenate hair follicles, and make the hair appear thicker. Ingredients like minoxidil, castor oil, rosemary, pumpkin seed oil, and menthol are recommended by experts for their benefits against dandruff, infections, dryness, and some alopecia forms. However, hair growth serums won't revive dead follicles for those with significant hair loss. According to hair restoration surgeon Dr. Alan J. Bauman, the best outcome is stabilizing further hair loss if hair follicles are irreparable or absent. So, for many experiencing thinning or wanting thicker hair, serums can be a valuable tool in their haircare routine.

With expert guidance, we tested 26 of the top-rated hair growth serums and evaluated the application, effectiveness, hair look, and feel. We also had a board-certified dermatologist on our Medical Expert Board review this article for medical and scientific accuracy.

What to Expect from Hair Growth Serums

  • Effectiveness: Results of hair growth serums may vary depending on the cause of hair loss and the specific product used. They are generally more effective for mild to moderate hair thinning but may not produce significant results for advanced hair loss.
  • Specific conditions: Before selecting a hair growth serum, consult a hair growth specialist or dermatologist. This will help you identify your specific hair concerns and goals, and choose a serum with the right ingredients that can have better chances of delivering positive results.
  • Application type: Hair growth serums come in oil and foam forms. Some require daily application, others only a few times a week. Choose an application type that suits your lifestyle for consistent use.

Why We Like It

Kerastase Initialiste Scalp & Hair Serum proved to be the best overall hair growth serum, thanks to its potent, scalp-nourishing ingredients and impressive results. We used this serum almost daily for six weeks. Applying it was simple: after showering, we used a dropper to apply the serum to our scalp, then rubbed it into our wet hair before drying. The serum is lightweight and non-greasy, and we noticed significant hair growth and increased thickness, particularly in previously thinning areas. Its gentle, irritation-free formula worked well with our hair, and the mild, floral scent doesn't linger. Our hair remained light and not weighed down, and our hair stylist observed a notable difference because a haircut was needed due to faster growth.

It's Worth Noting

  • While many find the fragrance mild and pleasant, some may find it unappealing or too strong.

Product Details

  • Size: 2.2 oz
  • Active ingredients: SP94, Ceramides, Green Tea Extract, Conditioning Agents and UV Filters
Kerastase Initialiste Scalp & Hair Serum displayed on a marble counter

Health/Paden Reich

Why We Like It

The Sephora Collection Strengthening Hair Serum has a biotin-rich formula that strengthens hair from the roots, promoting thicker, healthier growth, while phytoproteins provide essential nutrients, making it a top choice for revitalizing hair. The serum, easily applied with a dropper, quickly absorbed into our scalp, requiring 3-4 droppers for complete coverage. Although a mild tingling was felt, the serum didn't irritate or cause acne and was scent-free. Overnight application left our hair significantly volumized by morning, without greasiness. In four weeks, our hair became healthier and thicker, and layers notably grew, adding manageability and shine. Despite making our hair softer and less frizzy, it did become greasier more quickly. This serum was a beneficial, user-friendly enhancement to our nightly routine, offering noticeable improvements in the quality of our hair.

It’s Worth Noting

  • It may lead to quicker greasiness or heaviness in the hair, requiring more frequent washing.

Product Details

  • Size: 1.69 oz
  • Active ingredients: Biotin, Phytoprotiens

Why We Like It

Briogeo's Destined for Density MegaStrength+ Peptide Density Serum is specially formulated to tackle hair thinning, offering a nutrient-rich blend that supports hair density and fullness. Its peptide-infused formula nourishes the scalp and promotes healthier hair growth. We applied it nightly using the dropper bottle for precise, non-greasy, scent-free application. The serum noticeably increased hair density and was well-suited for our fine hair without causing scalp irritation. The jelly-like texture, though thick, didn't clump or make our hair greasy, proving that a little goes a long way. Post-use, our hair felt thicker and voluminous, with some overall hair growth, making it a staple in our routine.

It's Worth Noting

  • Those with fine or thin hair may find its thicker texture heavier and harder to spread than lighter, oil-based serums.

Product Details

  • Size: 1.5 oz
  • Active ingredients: Caffeine, CoQ10, Green Coffee Oil, Biotin, Copper Peptides

Why We Like It

The Philip Kingsley Density Preserving Scalp Drops are uniquely formulated drops that nourish the scalp and strengthen hair roots, effectively reducing shedding and boosting new growth, making it an essential pick for those battling hair loss. We used these drops daily. The application was incredibly user-friendly, thanks to the dropper in the cap with measurement marks. The oil felt light and quickly dried without leaving any heavy residue. The no-scent, non-greasy formula was a plus, making it easy to integrate into our routine. We noticed fewer hairs in our brush and observed new baby hairs sprouting. While our hair didn’t feel dramatically thicker, we saw promising signs of improvement, and even our editor's hairdresser of seven years commented on her hair feeling thicker. We would recommend it for its simplicity and noticeable results.

It’s Worth Noting

  • While it is effective, this serum is $70 for a one-month supply.

Product Details

  • Size: 2.87 oz
  • Active ingredients: Biomimetic Peptide blend, Azelaic acid, Pyridoxine HCL, Zinc PCA

Why We Like It

Wild Growth Hair Oil delivers an affordable solution that significantly boosts hair growth and fullness, particularly around the edges, without causing scalp irritation. Over six weeks of 2-3 weekly applications, the impressive improvements included healthier, fuller hair and recovered edges from heat damage, all without a greasy feel. The oil's natural, minty scent was distinct yet not overpowering. Ideal for thick hair, its slightly thick consistency requires only a small amount to be effective. We highly recommend it for its ease of use, noticeable results, and suitability for protective styles.

It's Worth Noting

  • The oil has a natural, minty fragrance that, while organic, may not be to everyone's liking.

Product Details

  • Size: 4 oz
  • Active ingredients: Coconut Oil, Olive Oil, Castor Oil, Jojoba, Eucalyptus
A person applies Wild Growth Hair Oil to their scalp

Health / Chantia Murphy

Why We Like It

Viviscal Hair Thickening Serum offers an effortless solution for instant volume. Its lightweight, silky formula noticeably thickens hair without weighing it down or leaving residue, making it an ideal choice for those seeking a fuller look. Applied 2-3 times weekly, its weightless, silky texture provided a mess-free application and left no residue. The scent was a mix of fresh and chemical-like, subtle and non-lingering. Our hair, which grows steadily, appeared fuller during the testing period, had a boost in volume, and enhanced silkiness. Although effective for instant volume, we'd prefer a more long-lasting solution for hair health.

It's Worth Noting

  • It's recommended for immediate enhancement, but other styling products may offer similar benefits.

Product Details

Size: 1.69 oz
Active ingredients:
Biotin, Keratin, Marine collagen, Seaweed extract

A bottle of Viviscal Hair Thickening Serum

Health / Ciara O'Grady

Why We Like It

Pattern Argan Oil Blend is perfectly tailored for dense texture. Its rich, thick consistency delivers deep hydration and enhances softness and shine without weighing hair down. Making it an ideal solution for maintaining the health and beauty of curls. Applied 4-5 times weekly, this oil was ideal for our editor's thick, curly hair, absorbing well without a greasy feel. After use, our hair appeared softer, healthier, shinier, and volumized. Our hairline appeared thicker, particularly in thinner areas, and it also helped with scalp hydration, reducing dryness and flakiness. While the oil seemed to be more effective in enhancing thickness than rapid growth, its benefits in moisturizing and softening make it highly recommended, particularly for those with thick, curly hair.

It's Worth Noting

  • If used on finer hair, it could potentially weigh it down and create a greasy appearance or feeling.

Product Details

  • Size: 3.9 oz
  • Active ingredients:  Argan oil, Apricot oil, Sunflower seed oil

Why We Like It

Augustinus Bader The Hair Oil’s lightweight formula, enriched with botanical extracts and oils, provides essential hydration and nourishment without adding extra greasiness, ensuring a balanced and healthy hair appearance. The texture was a thin oil, which was perfect for our editor's hair type (thin, straight, prone to greasiness). It didn't weigh our hair down, and there was no oiliness on our strands or scalp. The scent was gentle, subtle, and slightly floral.  After use, this serum felt luxurious and high-quality, making our air-dried straight hair look more like a professional blowout. During the testing period, our hair became softer, fuller, longer, and silkier. It enhanced our naturally straight and flat hair with noticeable fullness and shine, and the overall quality of our hair improved significantly.

It's Worth Noting

  • While the lightweight formula is great for people with oily hair, it may not offer enough moisture for those with extremely dry or coarse hair.

Product Details

  • Size: 1 oz
  • Active ingredients: TFC8, Baobab oil, Argan oil, Pomegranate oil, Vitamin E
Bomba Curls Dominican Forbidden Oil

Courtesy of Nordstrom

Why We Like It

Bomba Curls Forbidden Hair Oil is the ultimate solution for growing frizzy hair, offering a natural blend of nourishing oils that deeply moisturize and smooth unruly strands. Its unique formula not only softens and enriches hair texture but also leaves it more manageable and frizz-free. Applying Bomba Curls Forbidden Hair Oil was straightforward, and the oil's pleasant smell and gentleness on sensitive skin were positive. We like the product's natural ingredients and ease of use despite its tendency to leave a greasy appearance. After 5-6 weeks of use, we noted a richer hair color and softer, less frizzy texture. The oil's affordability, natural ingredients, and ease of use make it a valuable addition to our hair care routine.

It's Worth Noting

  • It has a tendency to leave hair feeling greasy and heavy, especially if not absorbed fully.

Product Details

  • Size: 4 oz
  • Ingredients: Coffee seed oil, Black Cumin seed oil, Rosemary extract, Castor oil

Why We Like It

K18 Molecular Repair Oil uses lightweight, nourishing oil that penetrates deeply to repair and rejuvenate, making it the best choice for those looking to revive their damaged, lifeless locks and restore their hair's natural vitality and shine. We applied this serum twice weekly, and its unique button-top dropper made effortless application. The oil, thinner than our usual preference, absorbed without residue, enhancing shine and reducing frizz in our thick, coily hair. Post-testing, our hair was revitalized, feeling excellent and free from usual dryness and frizz. Thanks to its lightweight nature, it didn't make our hair greasy or weighed down. The minimal, slightly citrusy scent was a refreshing contrast to typically fragrant products, and we experienced no irritation or tingling sensations, common with hair oils containing mint or tea tree oil. While it didn't offer wild hair growth, the product delivered on its promises, enhancing shine and reducing frizz.

It's Worth Noting

  • While it's effective in addressing dryness and frizz, it may not be sufficient as a standalone treatment for those with extreme hair loss.

Product Details

  • Size: 1 oz
  • Active ingredients: Caprylyl Caprylate/Caprate, Squalane, Avocado oil, Sunflower oil

Why We Like It

Ceremonia Aceite de Moska Silicone-Free Scalp Oil is a standout solution for postpartum hair loss, offering a nourishing blend of natural ingredients designed to rejuvenate and strengthen weakened hair. Its gentle yet effective formula is ideal for new mothers experiencing hair thinning, promoting healthier, fuller hair growth while providing the extra care and hydration needed during this transformative period. We used the growth oil 1-2 times weekly, and despite its runny texture, our hair felt hydrated, fuller, and healthier, with reduced split ends and no post-wash greasiness. During the testing period, we observed noticeable growth in shorter sections like bangs and baby hairs. This product had a positive impact on our postpartum hair recovery, with our hair growing an inch in six weeks (surpassing the average growth rate). This growth oil is suitable for all hair types and is vegan, gluten-free, and cruelty-free. It is also packaged in recyclable materials.

It's Worth Noting

  • It may be necessary to apply multiple servings to achieve thorough scalp coverage due to the relatively runny, greasy texture.

Product Details

  • Size: 2 oz
  • Active ingredients: Meadowfoam seed oil, Coconut alkanes, Chia seed oil, Babassu oil, Rapeseed oil, Patauá oil

Why We Like It

Taliah Waajid Gro Hair Gro Bamboo and Coconut Milk Growth Oil is the premier choice for combating traction alopecia, offering a nutrient-rich, hydrating formula. Infused with bamboo and coconut milk, Taliah Waajid Gro Hair Gro Bamboo and Coconut Milk Growth Oil strengthens hair follicles and promotes thicker regrowth, effectively addressing the key concerns of traction alopecia and promoting healthier, fuller hair.

We used this growth serum daily and found the application smooth thanks to its twist-top applicator. We enjoyed the tingling scalp sensation and how the oil left our hair soft and hydrated. It worked wonders with our coily hair, sealing in moisture without making our hair feel greasy or weighed down. However, it didn't reduce frizz. Over 6 weeks, we noticed significant growth, particularly on our edges, and the new growth felt stronger.

It's Worth Noting

  • Initially, the scent was overwhelming but didn't linger and felt natural and fresh.

Product Details

  • Size: 4 oz
  • Active ingredients: Sunflower seed oil, Sesame seed oil, Soybean oil, Avocado oil

Why We Like It

Women's Rogaine 5% Minoxidil Unscented Foam features a key ingredient clinically proven to stimulate hair growth and revitalize hair follicles, a crucial factor for those with androgenic alopecia, also known as female pattern hair loss. This lightweight foam formula harnesses the power of Minoxidil to effectively combat hair thinning, making it an essential choice for those seeking a proven solution to enhance hair density and promote fuller, healthier hair. We used this growth foam six times weekly. The lightweight, unscented mousse didn't weigh down our fine hair but lacked a direct scalp applicator for precise use. During the 6-week testing period, we did notice some hair growth. We only used half of the total product and observed an improvement in hair fullness, suggesting that with longer use we might see significant results.

It's Worth Noting

  • The mousse form made the application a bit messy and targeting the scalp challenging.

Product Details 

  • Size: 2.11 oz
  • Active ingredients: 5% Minoxidil

Why We Like It

The Nue Co. Supa Thick Scalp Serum is a game-changer for scalp health, delivering a unique formula that not only promotes hair thickness but also meticulously clears residue, fostering a healthier scalp. We used The Nue Co. Supa Thick Scalp Serum 2-3 times weekly, appreciating its easy application and pleasant rosemary scent. Initial applications caused some tingling but no irritation. We noticed hair growth and an increase in scalp thickness, and our hair held more volume when styled, likely due to the product's residue-eliminating effects.  Our hair felt thicker and lighter, allowing us to extend our hair-washing routine. While not as rapid as other serums for hair growth, it excelled in improving hair thickness and reducing scalp buildup.

It’s Worth Noting

  • Those looking for quick hair growth may find this serum's results slower compared to other hair growth treatments.

Product Details 

  • Size: 4 oz
  • Active ingredients: Redensyl, Probiotic, Rosemary, Clary sage, Peppermint

Our Testing Process

To determine the best hair growth serums, We tested 26 leading hair growth products, focusing on:

  • Application: Whether it was foam or oil and whether the process was difficult or messy
  • Frequency: How often we applied the product and whether it needed to be applied once per day or more often
  • Effectiveness: If we saw results and how quickly
  • Hair texture: Which hair growth serums worked best for particular types of hair
  • Appearance: If the serums made our hair appear greasy or wet after application

We strictly followed the manufacturer’s instructions, starting by recording the product's receipt date and our initial hair length. During the 6-week test, we avoided other hair growth products, applying the serum/oil post-wash using the dropper/applicator, and massaging it into our scalp and hairline. We followed the specified duration for use and applied it daily if no guidelines were provided. After using the hair growth products, we remeasured our hair length and recorded the results to evaluate their performance.

Our Experts

In addition to our tests, we consulted with dermatologists, trichologists, and hair restoration experts on the best ingredients to look for (and what to avoid) to treat the various causes of hair thinning and loss. These experts include:

  • Certified trichologist Bridgette Hill of Bridgette Hill Scalp Therapy in Palm Beach, Florida
  • Shari Sperling, DO, owner of Sperling Dermatology in New Jersey
  • Tiffany Young, trichologist and CEO of ThinHairThick
  • Hair transplant surgeon, Alan J. Bauman, MD, ABHRS, IAHRS, FISHRS, founder of Bauman Medical in Boca Raton, Florida
  • Paul Jarrod Frank, MD, board-certified dermatologist, skincare consultant, and founder of the bespoke aesthetic healthcare brand PFRANKMD

What To Know About Hair Growth Serums

If you're planning to purchase a hair growth serum, it's recommended that you consult with a hair growth specialist or a dermatologist first. This will help you identify your specific hair concerns and goals, and choose a serum with the right ingredients that can have better chances of delivering positive results. With the right product, you can avoid disappointment and achieve your hair growth goals more effectively.

Ingredients

Minoxidil

Minoxidil has long been the gold standard in hair regrowth and is recommended by renowned dermatologists like Dr. Paul Jarrod Frank. But minoxidil is not without its downside—some reported side effects include eczema and scalp irritation. There are some minoxidil-free formulas that contain DHT blockers, like saw palmetto and pumpkin seed oil, to inhibit a hormone that can cause hair loss.

Scalp Health Oils

To maintain healthy and vibrant hair, it is important to nourish your scalp. If you are experiencing scalp issues such as itchiness, dandruff, or irritation, try looking for topical solutions that contain salicylic acid. Alternatively, you can try using natural alternatives like rosemary, peppermint, and tea tree oils but avoid products with silicones and heavy oils.

Application Type and Frequency

Hair growth serums are available in two different forms - oil and foam. If you have thin or fine hair, then using a topical oil may make your hair look greasy. On the other hand, foam offers a lighter, mousse-like solution that is more easily absorbed if it gets into your hair. There are some topical solutions that need to be applied once or twice daily, while others can be used a few times a week or on the days when you wash your hair. It's important to choose an application type that suits your lifestyle and preferences so that you can use it more consistently.

Growth Effectiveness

When it comes to the effectiveness of hair growth serums, results can vary from person to person. The amount of growth you can expect depends on factors like the cause of hair loss and the specific product. Generally, these serums are more effective for mild to moderate hair thinning. While some may see noticeable improvements in hair thickness and health, they are not guaranteed to produce dramatic results, especially for advanced hair loss. It's important to talk to a dermatologist for advice that fits your situation.

Your Questions, Answered

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

You can take a before and after photo to determine if your hair is growing, especially if you are trying to treat bald spots. If you have thin or light-colored hair, it might only be noticeable if there's significant progress, so you can use your fingers to feel your hair and gauge if it seems like it's becoming thicker or denser after prolonged use. 

How often do I use these products?

Each product has different directions, but many are formulated for application once or twice daily. Some of our experts found leave-in products preferable, so keep an eye out for once-daily products that you can apply at night or leave on during the day. Some products are used before you wash your hair, while others get rinsed out after several minutes, like a hair mask. In any case, always follow the package directions carefully.

Who We Are

Alexandra Frost is a health and wellness journalist with over 15 years of experience interviewing physicians, and writing articles in the medical field. She has worked with other publications such as Popular Science, Huffington Post, and Washington Post, and has tested many products in her time as a journalist to help readers best understand what will work for them. She also has a Masters degree in education, and a Bachelor's degree in journalism, both of which she uses to help fully educate readers on health and wellness products she researches.

Rebecca Deczynski is a writer and editor. Her work appears in several publications, including Inc., DominoHealth, Shape, People, Refinery29Nylon, and Sweet. She received a degree in English from Barnard College in New York, NY.

Was this page helpful?
1 Source
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Most men experience hair loss—but it isn’t inevitable. NYU Langone News.

Related Articles