Most Hair-Thickening Products Don't Work, But We Found 12 Serums That Do



It can be a chore and a half trying to sort through the array of mysterious elixirs that claim to add volume and density to your hair. Do absolutely all of them work? No. But do at least some of them provide these kinds of benefits? Actually, yes, according to certified hair practitioner, PhD scientist, and Absolutely Everything Curly founder Gaby Longsworth. I picked her brain about this topic to get a little more solid information on thickening serums in particular. Here's what she had to share. 

"Hair-thickening serums work in the sense that they help with scalp and follicle health, as well as blood flow to the hair follicle, which indirectly then translates into healthier and stronger hair," she says. So there's a plus, but there are a few other things to keep in mind. "Serums do not magically make your hair grow faster. For most of us, our maximum hair growth reaches approximately half an inch a month. If a hair serum contains ingredients that bolster a healthy scalp environment, this will encourage and support healthy hair growth."

When selecting a serum, you'll also want to remember to check the label. "The way the hair serum is formulated is key," Longsworth adds. "It must contain the proper quality ingredients and the right concentration of those ingredients. Some hair serums do indeed 'thicken' the hair by depositing amino acids, hydrolyzed keratin, and other molecules onto the hair shaft, but this is an illusion as the hair strand doesn't actually grow thicker. This may still work fine for some people."

If you're still looking to invest, Longsworth also says that you should snag a hair serum that has ingredients like niacin, arginine, jojoba oil, amla oil, Brahmi herbs, and castor oil to promote blood flow in the scalp. To help with strand growth, try a serum that has ingredients like minoxidil, rosemary, antioxidants, biotin, vitamins like vitamin E, minerals, menthol, peppermint, and even salicylic acid.

To get you started, I've rounded up a few recommendations below along with a few of Longsworth's favorites in this department⁠—just keep scrolling.

1. Bellisso Biotin Serum for Hair Growth

This serum from Bellisso is specifically designed to improve your hair's thickness and volume while helping to prevent hair loss. It's a treatment that you leave on overnight and has biotin, sunflower, evening primrose, and lavender oils which coat your strands with a protective layer while you sleep.

2. Mo Mi Beauty Protect & Nourish Oil Based Serum

"This serum is good for both the scalp and nails and contains concoctions of herbs, amla (Indian gooseberries), and jojoba oil."—Longsworth

3. The Ordinary Multi-Peptide Serum for Hair Density

This hair-thickening serum from The Ordinary contains several unique ingredients that promote strand density. One is called Redensyl which targets stem cells in the scalp to improve overall hair density while Procapil increases blood flow in the scalp which allows hair to be more nourished and appear thicker. 



4. NaturAll Strengthening Jamaican Black Castor Oil Growth Serum

Longsworth describes this formula as "a nice combination of castor, peppermint, and coconut oil as well as rosemary and vitamin E." In addition to the strengthening and conditioning this growth-promoting serum provides, it has antioxidants that help reduce breakage, keeping your hair looking full and thick.

5. Camille Rose Cocoa Nibs & Honey Ultimate Growth Serum 

"The amla oil and Brahmi herbs in this clear blocked hair follicles for improved blood circulation and optimal scalp health to promote hair growth." —Longsworth

6. SheaMoisture Jamaican Black Castor Oil Hair Serum

Longsworth loves SheaMoisture's hair serum for curly and coily hair types because it's budget-friendly and highly moisturizing. Organic shea butter conditions dry or damaged hair while black castor oil strengthens and helps promote faster growth and strand density. 



7. The Innate Life Rose Hair Elixir

"This elixir is my favorite. It contains sea buckthorn oil which is rich in vitamins such as vitamin A, C, D, B, E, and K that are necessary for promoting healthy hair. It also contains rosehip oil which is rich in antioxidants, and vitamin A and E, which protect the hair against sun damage."—Longsworth

8. Nutrafol Growth Activator Hair Serum

I'm sure you've seen Nutrafol's Growth Activator Hair Serum around the internet quite a bit since folks seem to really love it. It's a fast-absorbing and lightweight serum infused with ashwagandha exosomes that boost cell renewal in the scalp. This in turn supports stronger and thicker-looking strands after just a few months of use.

9. Hair Restoration Laboratories Maximum Hair Thickening Serum

If you've been struggling with hair loss, it might be good to invest in a product that has high-strength, DHT-blocking ingredients like Hair Restoration Laboratories' thickening serum. The DHT-halting technology in this formula helps to block the negative effects of the hormone that can cause hair loss. It also has a blend of other ingredients like saw palmetto, biotin, pumpkin seed extract, caffeine, and green tea extract which encourages stronger, fuller, and healthier hair growth.



10. Pureauty Biotin Hair Growth Serum

This hair growth serum from Pureauty is actually part of a system with the brand's growth-promoting Biotin Shampoo and Conditioner. Although it works best when combined with these other products, it still works great alone as it contains biotin, provitamin B5, and pea sprout extract to help give hair a thicker appearance and strengthens it from within.

11. René Furterer Triphasic Progressive Concentrated Serum

This serum may have a complicated-sounding name, but all you need to know is that it works. It contains an array of effective ingredients like Pfaffia Extract, lavender oil, Biotrinine, squash seed, licorice extract, and more to support natural hair growth. It also visibly redensifies thin or sparse hair by penetrating deep into the hair shaft.



12. Groh Stimulating Scalp Serum

Groh's oil-free hair serum contains an antioxidant called Ergothioneine which has a unique transporter that delivers the bio-nutrients in this formula directly to skin cells in the scalp. Basically, that's a fancy way of saying it's highly effective at promoting a healthier hair follicle and increases growth and hair density fast.