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.