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Which hair serum is best?

Your hair deserves some special care, and a hair serum is an excellent product to incorporate into your hair care regimen. It can strengthen, protect and create a much nicer result as you style your hair. 

Kerastase Elixir Ultime L’Huile Hydrating Hair Oil Serum is a universal serum for all hair types made to restore and replenish brittle hair. It’s a triple protector from heat, frizz and damage.

What to know before you buy a hair serum

Hair type

Start by asking yourself questions about your hair type. Is your hair thick or thin? Is it naturally coiled, curly or straight? Do you wear your hair in a protective style? Is it dry, or is your scalp too oily? Is your hair textured or not? The more questions you answer about your hair, the more details you have to work with when you’re looking for the best hair serum.

Your needs

After identifying your hair type, think about what you want from a hair serum. For example, if you’re trying to rehydrate your hair after coloring it, opt for a serum that focuses heavily on moisturization. As for damaged and rough hair, a product emphasizing split end repair may be a better choice. Learn your hair needs and prioritize them as you look for a hair serum.


Review the ingredients of any product you’re considering. Keratin, argan oil, Moroccan and jojoba oils are some of the most common ingredients you’ll find in hair serums, and each has different effects on your hair. Keratin is a protein used for breakage repair and split ends. Argan and Moroccan oils are suitable for dense and thick hair types. Jojoba oil is ultra-hydrating and is very thin and light, making it a great choice for curly hair types.

What to look for in a quality hair serum

Clean products

As the cosmetics industry becomes more eco-friendly, more “clean” hair products are available. Some hair serums may contain chemicals, sulfates, parabens or artificial fragrances, so keep this in mind when looking for a product. The fewer ingredients, the more your hair will thank you. Harsh synthetic materials only coat your hair and leave it temporarily hydrated, but serums with a high density of elements like keratin and argan oil can penetrate and heal your hair.

Minimal usage

If a hair serum is doing its job correctly, you should only use it every few days. A product of high quality should be enough to keep your hair shining and healthy in between uses.

Additionally, a little goes a long way when it comes to hair serums. Only a pea-sized amount is necessary for most hair serums to cover your hair. Using too much serum overcorrects hydration, and you may find your roots and ends look greasy and wet.


A well-crafted hair serum can give you noticeable results within a month or so. Pay attention to your hair and track its progress based on your goal (reduce dryness, frizziness, retain elasticity). If you aren’t seeing any changes to the feel or look of your hair, it may be wise to change products. The lack of results may be due to choosing a product that doesn’t work for your hair type or it may indicate a poor-quality product.

How much you can expect to spend on a hair serum

You can anticipate spending $20-$50 on hair serum, based on your hair goals.

Hair serum FAQ

Should I wash my hair after using hair serum?

A. This depends on the product you’re using. More often than not, hair serum is used after washing your hair and before you use heat tools on it. Sometimes serum is used on dry hair to add shine and moisture after using heat tools.

Where do I apply hair serum?

A. Hair serum is used mostly on your mid-length to ends, but this varies based on the product you purchase. If you’re trying to rehydrate your scalp, choose a hair serum specializing in root restoration to prevent an oily appearance.

What’s the best hair serum to buy?

Top hair serum

Best Kerastase Elixir Ultime Hydrating Hair Oil Serum

Kerastase Elixir Ultime L’Huile Hydrating Hair Oil Serum

What you need to know: This lightweight oil-based serum is a harmony of four essential oils: maize, pracaxi, argan and camellia.

What you’ll love: Frizz and dullness will be a thing of the past with this product. It’s multipurpose and can be used before or after you shower, giving you a boost before you shampoo or a finishing touch to add shine.

What you should consider: The product doesn’t indicate if it’s vegan or gluten-free.

Where to buy: Sold by Amazon and Sephora

Top hair serum for coiled and curly hair

PATTERN Jojoba Oil Hair Serum

Pattern Jojoba Oil Hair Serum

What you need to know: Your hair will feel more nourished and loved with this jojoba oil-based serum.

What you’ll love: Made from safflower, jojoba, rosehip, olive and lavender oils, you can use this combination serum on the scalp or throughout your hair to deliver moisture and revive your natural shine. It’s residue-free, so you don’t have to worry about product buildup. 

What you should consider: This hair serum is highly concentrated oil, so only a drop or two is necessary for each use.

Where to buy: Sold by Ulta Beauty

Top hair serum for scalp treatment

Best Ouai Scalp Serum

Ouai Scalp Serum

What you need to know: By supporting scalp health, this serum encourages thicker, fuller hair. 

What you’ll love: The nourishing ingredients, such as hyaluronic acid and ginseng, hydrate the scalp. It has a pleasant scent with earthy notes of green fig and basil. It’s suitable for all hair types.  

What you should consider: Some users don’t notice much difference in scalp health. 

Where to buy: Sold by Amazon and Ulta Beauty

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Isabella Acitelli writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

BestReviews spends thousands of hours researching, analyzing and testing products to recommend the best picks for most consumers.

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