both contain zinc. Otherwise, Dr. Lolis suggests: “Look for active ingredients like biotin and caffeine, which improve hair strength and stimulate growth.”
Do hair-growth serums work?
“Many hair-growth serums include non-medicated ingredients,” Dr. Amin says. (Translation: You don’t need a prescription for most of them.) “The efficacy of the serums is difficult to ascertain because there are not many randomized controlled clinical trials.”
However, anecdotally, Lolis has seen evidence that the serums work—especially when they’re used as intended. “Ingredients like biotin and caffeine support the scalp’s environment, helping nourish hair follicles, which can result in denser, stronger hair [over time],” she says. In short, the how-tos on the packaging are required reading, and you should try to adhere to the recommended guidelines if you want to feel blessed in the hair follicles department.
How long does it take to see growth?
“Most users report seeing visible improvements, such as reduced shedding and new hair growth, after about three months of consistent use,” Dr. Lolis says. Dr. Mian agrees, adding that patience is key here. “Hair-growth serums can take a while to show their efficacy,” she says. “I would use a serum for at least three months before deciding if it’s working or not.”
Meet the Experts
How we test and review products
We always enlist a range of testers for our makeup vertical, but hair-care products and tools are another story. While there are certainly products that can be used across different hair textures, lengths, curl patterns, thicknesses, colors (natural and unnatural), and needs, hair products are often created with specific consumers in mind. Many are created in order to address a concern (dandruff, breakage, brittleness) or to work most effectively for a specific hair type (4C curls, wavy hair, gray hair). You wouldn’t want to pick up a purple shampoo that’s only been reviewed by someone with, say, auburn hair, or a diffuser that’s never been tested by anyone with curls—right?
For our review of the best hair growth serums, we enlisted the help of multiple editors, writers, contributors, and dermatologists to find the most hydrating, strand-softening formulas out there. Testers considered performance across four primary categories: efficacy, texture and experience, fragrance, and packaging. For more on what’s involved in our reporting, check out our complete reviews process and methodology page.
Our staff and testers
A beauty product is a personal purchase. You might be searching for a face cream to address persistent dryness or a new nail product to add to your Sunday self-care routine; you may simply be browsing around for the latest launches to hit the hair market. No matter what you seek or your individual needs and concerns, Allure wants to ensure that you love anything we recommend in our stories. We believe that having a diverse team of writers and editors—in addition to the wide range of outside testers and industry experts we regularly call upon—is essential to reaching that goal.