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If your skincare routine includes more than four steps, you probably have a serum or two in your arsenal. These lightweight formulas contain concentrated doses of various actives and complexion-enhancing ingredients, like retinol, vitamin C, and hyaluronic acid. Similarly, hair serum is any light, liquid styling product that gives your hair a boost of nourishment and finesse.
"Serums are a very effective means of adding moisture and nutrients to hair [while] sealing it off so it can repel humidity and fight frizz," notes renowned session stylist and product developer Kevin Murphy. They can help with the effects of humidity, soften coarse hair, add shine, tame flyaways—you name it.
Keep scrolling for a rundown of the best hair serums you can buy today.
Best Overall: BioSilk Silk Therapy Original
For an all-around amazing serum that works for all hair types, you can't go wrong with Silk Therapy. BioSilk's original formula contains smoothing and conditioning ingredients like panthenol, dimethiconol, and alkyl benzoate, as well as ester of hydrolyzed silk.
Squirt a few drops onto the palms of your hands and work it through wet or dry hair. The result? Shiny hair that not only appears healthy but also feels just as luxuriously soft as it looks. You can use it daily or any time your hair needs a little TLC. Not only that, but the paraben-free formula also works as a skin serum.
Best Budget: Garnier Fructis Sleek & Shine Anti-Frizz Serum
On a budget? You can still reap the benefits of using a hair serum, thanks to Garnier Sleek & Shine. Containing a blend of argan and apricot oil, the anti-frizz formula offers a supremely smooth finish.
Best Drugstore: John Frieda Frizz Ease Original Hair Serum
The first product offering from the timeless beloved line, Frizz Ease Original Serum is a must-have for getting flyaways under control. The classic silk-infused formula seals split ends and leaves a gorgeous shine in its wake.
What Our Testers Say
"John Frieda's Frizz Ease Original Hair Serum is a fan-favorite for a reason: It works and it’s affordable, too. The serum did a surprisingly good job at smoothing my hair." — Joline Buscemi, Product Tester
Best Treatment: Olaplex Hair Perfector No. 3
Olaplex No 3 was made for bleached, dyed, and chemically straightened hair. With once-a-week use, this reparative treatment serum mends breakage and nourishes stressed hair, offering a healthy-looking finish.
Best for Natural Hair: Pattern Jojoba Oil Hair Serum
Tracee Ellis Ross knows a thing or two about natural hair, and her brand's beloved Jojoba Oil Serum was formulated with curly, kinky, textured hair in mind. Ingredients like jojoba, safflower, olive, and rosehip oil work to moisturize dry hair while reducing breakage and leaving your hair smelling like a slice of heaven.
Best Oil: Mielle Organics Rosemary Mint Scalp & Hair Strengthening Oil
Oil-based serums can be a dream come true for curly or notably thick hair. With this in mind, Mielle's Strengthening Oil nourishes hair follicles and smooths split ends with a nourishing blend of soybean, castor, rosemary, peppermint, and tea tree oils.
Best for Flaky Scalps: Briogeo Scalp Revival Charcoal + Tea Tree Scalp Treatment
Flaky, itchy hair? Reach for Briogeo's Scalp Revival. This little tincture is infused with charcoal, witch hazel, and tea tree oil to soothe as it relieves dry, irritated scalps.
Best Multitasker: Beneath Your Mask Nourish Skin & Hair Serum
We love a good multi-use beauty product, and Beneath Your Mask Nourish Serum doesn't disappoint. The little dropper bottle contains a moisturizing, fortifying blend of plant-derived oils, like hemp seed, safflower, and rosehip, which thirsty skin and dehydrated hair will drink right up.
Best Smoothing: Paul Mitchell Super Skinny Serum
If it's smooth hair you're after, your best bet is Paul Mitchell's Super Skinny. This best-selling hair serum works as a blowout primer, but you can also use a pump or two on dry hair for an ultra-shiny, healthy-looking finish.
Best Nourishing: Aunt Jackie's Nourish My Hair Flaxseed & Monoi
Dry, brittle, or overprocessed hair? You can count on Aunt Jackie to deliver the nourishment it needs. This rich hair serum contains ingredients like Jamaican black castor oil and vitamin E to rejuvenate your tired hair and improve scalp health.
Best Reparative: Kevin Murphy Young Again Oil
Murphy formulates his haircare with many of the same ingredients you'd find in top-shelf skincare products. Young Again contains reparative components that help add moisture, luster, and elasticity, such as lemon peel oil, safflower seed oil, and green tea extract.
Best Fortifying: Sally Hershberger 24K Golden Touch Nourishing Dry Oil
To fortify your hair, celebrity hairstylist Sally Hershberger recommends 24K Golden Touch Nourishing Dry Oil. "It adds weightless control to tame frizz, provides protection from heat, UV, and color fade, and it hydrates hair," she explains.
Best Protective: Amika Blockade Heat Defense Serum
Amika's take on hair serum is this brilliant heat-protectant formula. Blockade is a nutrient-dense elixir formulated to safeguard your hair from the heat of a blowdryer and other hot hair tools while creating a humidity-resistant barrier to prevent frizz.
The best serum overall is definitely BioSilk Silk Therapy Original (view at Amazon). It works for all hair types, can be used on wet or dry hair, and contains ester of hydrolyzed silk to deliver ultra-smooth, shiny hair. That said, those with natural hair should consider Pattern Beauty Jojoba Oil Hair Serum (view at Ulta), and anyone with bleached or chemically treated hair should go with Olaplex Hair Perfector No 3 Repairing Treatment.
What to Look for When Buying a Hair Serum
As Murphy explains, hair serum is not unlike face serum in that it offers a concentrated dose of moisture, nourishment, or a smoothing effect without leaving a residue behind. To that end, you'll want to look for many of the same ingredients you'd find in high-quality skincare products. This includes natural oils, vitamin E, cyclomethicone, dimethicone, alkyl benzoate, hydrolyzed silk, tea tree extract, green tea extract, and glycerin.
Like skincare serums, some hair serums contain nothing more than plant-sourced oils, such as jojoba, coconut, argan, apricot, lemon peel, rosehip, castor, and safflower seed. Additionally, you'll find that many are blended with oils and lightweight ingredients.
Options heavy on the oils are ideal for treating damaged, brittle, or dry hair, and they tend to work best for thicker hair. For this reason, those with fine hair may want to avoid oil-based formulas, as the heavier liquid can weigh down hair.
Frequency of Use
Lightweight hair serums are generally meant to be used for daily styling, as they offer frizz control and a smoothing effect. However, thicker, oilier options are intended for treating the hair once or twice a week. So, how do you know the difference? Look at the directions to see the recommended frequency of use.
What are the benefits of hair serums?
Most hair serums nourish your hair, hydrate dry hair, and control frizz. "By refining the surface of the hair, they can help to shut the cuticle and create shine as well. A topcoat of serum is a really good way to keep the good stuff in and the bad stuff out while improving elasticity and therefore the manageability of your hair," adds Murphy. "They also can offer protection from environmental factors like pollution, wind, and sun."
How do you decide what type of serum to use with your hair type?
According to Murphy, your hair texture number (which refers to the number of hair fibers and their density) can offer some clues. "Generally speaking, the higher your texture number, the heavier the serum can be," he explains. Those with bleached or highly processed hair can use heavier options with higher oil contents, but everyone else should go with lighter formulas.
Can you use a facial serum in your hair?
In most cases, facial serums can be applied to hair. As mentioned above, hair and skincare serums are made with many of the same ingredients, so they can often be used interchangeably. Additionally, some multi-use hair serums are formulated to offer benefits to your face, body, and hair.
Why Trust Byrdie?
Theresa Holland is a seasoned commerce writer specializing in beauty and wellness. She's been writing for Byrdie since 2020, where she covers fitness, makeup, skincare, and haircare. As a serum enthusiast, she's tried several products on this list and is a big fan of BioSilk, Kevin Murphy, Olaplex, Briogeo, Amika, and Etude House.