Every product on this page was chosen by a Harper's BAZAAR editor. We may earn commission on some of the items you choose to buy.
When you look at your hair brush, there will almost certainly some hair left behind. Often, there's nothing to worry about; shedding is perfectly normal, but when it starts happening more quickly and in higher quantities, there may be other factors at play. There are several causes of hair thinning; whether it's postpartum, nutrition, stress, illness (such as COVID-19), or simply aging, many people experience some form of hair loss, at some point.
But that doesn't mean you and your hair can't get a boost, in the form of hair growth serums. These products have gotten way more attention in recent years, though as with hair growth supplements, the research is still limited. "There's limited data on hair growth serums for thinning hair compared to FDA-approved minoxidil [i.e. Rogaine], but some preliminary data are very hopeful," Minnesota-based dermatologist Jenny Liu says.
Still, if the thousands of reviews are to be believed, many users have found success with these formulas. Ahead, we compiled 13 of the best hair growth serums to consider, including picks from Liu as well as celebrity hairstylist Clariss Rubenstein.
The Best Hair Growth Serums
Best Strengthening Serum
Nutrafol Lightweight Thickening-Hair Serum for Thinning Hair
Read more
Best for Alopecia
The INKEY List Caffeine Stimulating Scalp Treatment
Read more
Best for Thinning Spots
Vegamour GRO Hair Serum for Thinning Hair
Read more
Best for Hairline Growth
AAVRANI Hair Density Boosting Treatment for Thinning Hair & Hair Loss
Read more
Best Strengthening Serum
Nutrafol Lightweight Thickening-Hair Serum for Thinning Hair
Best Strengthening Serum
Nutrafol Lightweight Thickening-Hair Serum for Thinning Hair
Pros
- Addresses hair breakage
- Suitable for all hair types and textures
Cons
Nutrafol is one of the only hair-growth supplements that actually work, so you can trust that the brand's hair serum is worth the investment. Made with protein-rich ashwagandha exosomes, Irish moss peptides, and pea sprout extract—all of which help strengthen and hair and promote thickness—it's the ideal complement to taking the supplements.
What the reviews are saying:
"Great product. Been using it for 3 weeks now. I have noticed less hair fall in my comb. Does not leave hair greasy. I am combining with the vitamins." —Lili2022
Best Non-Greasy Serum
Undefined Beauty R&R Scalp Serum
Best Non-Greasy Serum
Undefined Beauty R&R Scalp Serum
Pros
- Hydrating ingredients
Cons
If you get turned off by the greasy results from hair and scalp oils, consider this water-based formula. Featuring nourishing ingredients like plant peptides, niacinamide, ashwagandha, and caffeine, it helps stimulate hair growth as it supports scalp health.
What the reviews are saying:
"I've been using this daily for about two-ish weeks. While I can't comment if it's helping my hair grow, I will order another bottle to get the full effect as you typically can't see changes in 30 days. It smells great and doesn't leave my hair super oily either. I like to apply it at night so that I don't mess with my hair after application."
Pros
- Soothes dry scalp
- Safe for color-treated hair
Cons
Dani Austin's hair care line has a devoted following, in part thanks to this scalp serum (it has over 12,000 reviews!). Containing copper tripeptide-1 for growth, tea trea oil to soothe the scalp and detox, and invigorating menthol and peppermint oil, it helps improve circulation, remove buildup, and give hair an overall thicker appearance.
What the reviews are saying:
"I had a bald spot on the top of my head, and thinning of hair all around. I started using a natural shampoo plus Divi. Man, within of one month of CONSISTENT use my hair grew back and then some!" —Jen
Advertisem*nt - Continue Reading Below
Best for Alopecia
The INKEY List Caffeine Stimulating Scalp Treatment
Best for Alopecia
The INKEY List Caffeine Stimulating Scalp Treatment
Pros
- Great price
- Derm-approved
Cons
This overnight treatment is made with caffeine and redensyl to combat hair loss, as well as conditioning betaine. Liu recommends this inexpensive option for those with alopecia, also called androgenetic hair loss.
What the experts are saying:
“Caffeine has preliminary data to support hair growth, especially for androgenetic hair loss,” says the derm.
Hairstylist Pick
Monat Hair Thinning Defense
Hairstylist Pick
Monat Hair Thinning Defense
Pros
- Works quickly
- Fragrance-free
Cons
Rubenstein “loves” this serum from Monat containing caffeine, antioxidants, and melatonin. Plus, it has a lightweight consistency and is fragrance-free.
What the experts are saying:
“It promotes hair growth, density, scalp health, and is totally safe to use daily,” says the hairstylist.
Best for Thinning Spots
Vegamour GRO Hair Serum for Thinning Hair
Best for Thinning Spots
Vegamour GRO Hair Serum for Thinning Hair
Pros
- Impressive clinical results
Cons
Vegamour is renowned in the hair-growth space, and the clinical studies support it too: 52 percent of subjects saw an increase in the appearance of hair density, while 76 percent saw a reduction in hair shedding. Plus, it's pleasantly scented with bergamot essential oil
What the reviews are saying:
"I’ve only been using Gro for three months and already have amazing results! I had severe postpartum hair loss that just wasn’t returning after having my baby 18 months ago. My thinning areas haven’t filled in completely yet, but if I’ve had this much success in only 3 months I can’t wait to see it at the six month mark!"
Advertisem*nt - Continue Reading Below
Best Lightweight Hair Serum
Nécessaire The Scalp Serum
Pros
- Skincare ingredients
- Soothes the scalp
Cons
- Needs to be used consistently in order to see results
If you hate the feeling of heavy products on your scalp, consider this lightweight, leave-in formula that feels more like a face serum. It features a five percent biomimetic peptide blend to support thinning, plus hyaluronic acid to hydrate, and green tea to soothe itchiness. Plus, it won't leave any residue on your scalp.
What the reviews are saying:
"I love how lightweight this is. It almost feels like water and has no scent. It is not greasy so I can apply it between washes on dry hair." —Emily R.
| Size | 2 oz |
|---|---|
| Hair Type | All Hair Types, Including Color-Treated |
| Active Ingredients | Biomimetic Peptide Blend, Hyaluronic Acid, Niacinamide and Vitamin B3 |
Best Oil-Free Scalp Serum
Inala Power Potion
Best Oil-Free Scalp Serum
Inala Power Potion
Pros
- Great for textured hair
- Lightweight formula
Cons
This daily treatment has a bevy of strengthening ingredients like rice water extract, biotin, and arginine to nourish the scalp and roots. It's also oil-free, and can be applied to wet or dry hair.
What the reviews are saying:
“I swear by The Inala Power Potion. My edges are back and my problem areas have new growth.” —Ebone
Best for Hairline Growth
AAVRANI Hair Density Boosting Treatment for Thinning Hair & Hair Loss
Best for Hairline Growth
AAVRANI Hair Density Boosting Treatment for Thinning Hair & Hair Loss
Pros
- Nice smell
- Doesn't weight hair down
Cons
This collagen-infused hair serum is touted for hydrating the scalp while promoting the thicker, fuller hair – all without disrupting your current hairstyle.
What reviews are saying:
"The Hair Density Boosting Treatment is my new holy grail product. After 8 weeks of daily use, my wavy hair is noticeably fuller and sheds less. The serum is lightweight, easy to apply and leaves no greasy residue - just a pleasant fragrance. A must-have for healthier, thicker hair!" – Nikkicherie
Advertisem*nt - Continue Reading Below
Best for Fast Results
Act+Acre Cold Processed Stem Cell Serum
Best for Fast Results
Act+Acre Cold Processed Stem Cell Serum
Pros
- Impressive clinical results
Cons
- Some said it made their scalp feel greasy
Act + Acre, a brand built on scalp care, uses two percent Swiss apple stem in its scalp serum. Use it daily to see less thinning and more hair density in just 30 days, and to soothe the scalp.
What the reviews are saying:
"I haven’t been using this product for very long, but I am already seeing less hair in my shower drain. And my stylist has noticed how much better my hair looks."
Pros
- Great price
Cons
This affordable serum is made with three percent Redensyl and two percent Capixyl (hence the name), to quickly absorb without leaving a residue. And while some hair growth products can have a clinical smell, but this highly rated serum has a fresh fragrance.
What the reviews are saying:
"I have been using this for almost a year. It does take a little time but it works. New hair growth comes in and you just need to keep at it. My thinning spot on my crown has filled in slowly." —Connie M.
Best Overnight Scalp Serum
Agent Nateur Holi(locks) Strengthening Hair Growth Serum
Best Overnight Scalp Serum
Agent Nateur Holi(locks) Strengthening Hair Growth Serum
Pros
- Helps strengthen hair
Cons
A combination of watermelon seed, pumpkin seed, green tea, and more extracts make up this formula. You can leave the treatment oil on for as little as 30 minutes, or as long as 12 hours; either way, you’ll start noticing less fallout and stronger hair in 12 weeks.
What the reviews are saying:
"This product is magical. I’ve used it 2-3 times a week for six weeks and it’s greatly improving my hair." —Stella9907
Advertisem*nt - Continue Reading Below
Best Balancing Scalp Serum
Better Not Younger Superpower+ Advanced Hair Densifying Scalp Serum
Best Balancing Scalp Serum
Better Not Younger Superpower+ Advanced Hair Densifying Scalp Serum
Pros
- Multitasking formula
Cons
Don't love an oil-based formula? This has a refreshing gel texture that absorbs easily into the scalp. In addition to rosemary oil—which has been studied for its hair-growth properties—it also features apple cider vinegar, which the real ones know is a must for a balanced scalp.
What the reviews are saying:
“Don't know if my hair is getting thicker yet, but my hair's texture is so soft and silky. And my scalp feels nice and hydrated. And the voume and bounce has returned to my hair.” –Velvet
| Size | 2.0 fl oz |
|---|---|
| Hair Type | Thin |
| Active Ingredients | Rosemary Extract, Apple Cider Vinegar, Proprietary Superpower Blend |
Frequently Asked Questions
What ingredients should you look for in a hair growth serum?
Several ingredients can help in the hair-growth journey. "Caffeine and topical pumpkin seed oil extract has been demonstrated in small studies to demonstrate efficacy, plant derived flavonoids and other antioxidants possibly as well," Liu says. Rubenstein echoes the caffeine recommendation, and adds biotin to the list. "Biotin supports hair health. You need things that stimulate growth but also support the new hair," the hairstylist says.
Advertisem*nt - Continue Reading Below
How do you apply hair growth serums?
In general, you apply directly to the scalp, then massage them in (enjoy the extra moment of self-care). But be sure to read the instructions, as some products should be washed out, while others are left in. Use once or twice a week, or even daily depending on the product. "Depending on what’s in it the frequency of suggested use may vary," Rubenstein says.
Meet the Experts
- Jenny Liu, MD, FAAD, is board-certified dermatologist based in Minnesota.
- Clariss Rubenstein is a celebrity hairstylist who has worked with Jennifer Garner, Dakota Fanning, and Mindy Kaling.
Why trust Harper’s Bazaar?
For more than 150 years, Harper’s Bazaar has been the preeminent fashion and beauty resource for women at every age. We cover what’s new and what’s next in beauty by working with the world’s leading authorities in dermatology, plastic surgery, cosmetics, skincare, hair care, and fragrance. Every story we publish has been thoroughly researched and vetted by our team of beauty editors and industry experts.
Lindy Segal
Lindy Segal is a beauty writer and editor. In addition to regularly contributing to BAZAAR.COM, she also writes for Glamour, People, WhoWhatWear, and Fashionista, among other publications. She lives in New York City with her Chihuahua mix, Barney.
