11 Hair Serums That Really Work, According to Our Beauty Scientists

The winner the GH Beauty Lab anti-frizz products test, this Orlando Pita Play serum-cream hybrid was rated best for leaving hair feeling smooth and frizz-free right after styling and was loved for keeping hair soft and crunch-free. Plus, this lightweight formula conditions without weighing hair down. "It left my hair shiny, frizz-free and with body, not flat!" one tester commented. "My curls looked amazing."

Garnier's classic silky serum scored at the top in past GH Beauty Lab anti-frizz stylers testing, and contains a combination of silicones that surround and protect hair from swelling in humid conditions. Consumers ranked it high for preventing frizz and keeping hair shiny, and 91% said they would continue using it. "The product made my hair smooth, shiny, silky, and frizz-free!" one said. 

This oil-based hair serum from Pattern is formulated with botanical oils such as safflower and jojoba, and contains no silicones (some types of silicones that are not water-soluble may cause buildup on delicate curls that can be difficult to rinse). GH Beauty Lab scientists tested the serum on frizzy curls, which were left soft, smooth, and flexible after the treatment. 

For sleek, straight strands, turn to this Goldwell serum-oil hybrid. GH Beauty Lab testers ranked it high for keeping hair smooth throughout the day and not leaving any film behind. "Love everything about it," a tester raved. "It smoothed my hair with no residue," one tester raved. The formula also scored the highest in the test for adding shine. 

This Aloxxi thickening serum, a GH Beauty Lab test winner, noticeably turns up hair volume without sacrificing softness. In Lab evaluations, it increased the diameter of individual strands. Plus, the formula had "no sticky feel or heaviness at all" and helped hair "hold curl better." 

This treatment serum from Rogaine is the only one proven to treat hair loss and stimulate growth. "The only over-the-counter topical drug approved by the U.S. Food and Drug Administration (FDA) to treat hair loss is minoxidil," says GH Beauty Lab chemist Danusia Wnek. The serum with 2% Minoxidil is clinically proven to regrow up to 25% more hair during the first stages of hair thinning. It works by boosting hair follicle activity and stimulating hair protein production to help regrow fuller hair. 

If your hair is frizz prone, look no further than this super-powered version of the iconic John Frieda anti-frizz serum. It tamed one user's stubborn frizz in one application. Apply it to soaking wet hair with a light touch, using more if your hair is extra thick, to lock in moisture. Blow-dry for a smooth finish or let hair air dry, letting texture form sans frizz or flyaways.

Whether your hair is tight curls require intense moisturizing to keep spirals protected from frizz and damage. Shea Moisture's hair serum is packed with super hydrators such as castor oil and shea butter to get the job done. With 1,264 Amazon shoppers vouching for its shine and softness benefits (4.4 stars!), this serum is also sustainably-produced and doesn't weigh down hair. 

This Kérastase serum dispenses oil and cream formulas from a dual-chamber bottle that mix together before application. The concoction slides effortlessly into towel-dried hair to bring vitality back to brittle strands. GH Beauty Lab scientists confirmed that this serum made damaged hair smooth and silky without weighing it down.

Hair serums meant to boost fine, straight hair while also protecting it from breakage and frizz are tough to find, as building volume usually falls under the domain of thickening mousses and sprays. This lightweight texturizing serum from Davines impressed the GH Beauty Lab's senior chemist. It gives light grip to fine, straight hair all while keeping it full and conditioned. Apply the serum to damp hair and style as usual for flexibility without stiffness. Bonus: It has a distinctive warm, slightly spicy yet subtle fragrance.

Redken's serum lives up to its name by keeping frizz and flyaways at bay for GH beauty assistant Katie Berohn. "I can let my hair air dry without worrying that it's going to be frizzy, and it will stay smooth all day long," she says of this "life-changing" serum. It has sustainably-sourced babassu oil, which is known to enhance shine and silkiness. "A little goes a long way" (she's had her bottle for over a year and still has a lot left!) and it also "smells really good," Berohn notes.