33,172 reviews

new

custom hair serum

3oz - $24.99

A lightweight finishing product that helps enhance shine, smooth frizz + flyaways, and increase your hair's overall manageability.
Formulated with a hair-healthy blend of argan, jojoba, and sunflower oils, and a custom blend of natural ingredients depending on your hair goals.
100% customizable and designed to work specifically for your unique hair type and goals.
Proven to reduce frizz by 70%, increase shine by 26 times more than untreated hair, improve detangling by 75%, and thermally protect hair from damage up to 400 degrees.

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ingredients

All Function of Beauty products are formulated without sulfates, parabens, phthalates, mineral oils, or gluten. Our products are also all certified vegan and cruelty-free.

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recommended use

Warm a small amount of product in your hands and apply to wet or damp hair. Using your fingers, distribute the product evenly from the mid-shaft to ends, working your way through the length of your hair. Make sure to avoid the roots. Do not rinse out, and style as you’d like!

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great for...

Hair serum is recommended for those who are looking to tame frizz and add an added boost of shine to their hair. It is specially formulated for your unique hair goals and needs, making it a great option for all hair types, although it is particularly recommended for those with coarse, curly, and/or coily hair types.

Hair Serum is proven to reduce frizz by 70%, increase shine by 26 times more than untreated hair, improve detangling by 75%, and thermally protect hair from damage up to 400 degrees.

the people have spoken

I used it both with heating tools and air dry and I loved both.

-Elaine

Very nice for fine thin hair. Would have liked more volume. But didn’t weigh my hair down which is a major plus.

-Jen

I freaking love the hair serum I’ve tried it like: with damp hair and blow dry; with heat tools; after straightening for shine. I am absolutely in LOVE! It helps in alllll aspects I want it to for my hair.

-Vanessa

I had to walk in the rain after drying my hair and I felt this serum kept my hair smooth. Normally rain would cause it to curl and frizz.

-Mindi

Really liked getting to try out the hair serum. I have very thick hair and it helped the drying and styling process go Smoother. It helped manage my frizz and gave it a healthy shine.

-Michelle

I don’t usually use hair serum because it’s very oily on my hair. This product however was not at all. It went on smooth and soaked in right away, not leaving any oily feeling behind. Def liked it a lot!

-Jenn

Overall, I loved the serum. Made my hair soft & managable, no frizzies.

-Lisa

The above testimonials were shared by customers who received a sample as part of our testing group.

got questions?

How does the serum work?

Our serum creates a light film that coats the damaged cuticles to make hair appear less frizzy while also preventing moisture loss. This film also reflects light and gives hair shine and luster (aka that gorgeous glass hair look).

Will it make my hair oily?

Your customized hair serum is meant to be applied to the ends and mid-shaft, avoiding the scalp entirely. If you’re using the small recommended amount, it should not make the hair oily. Be sure to also start with just a small amount and add more only where needed!

Can I use it in addition to leave-in treatment?

Yes, leave-in treatment and serum are a great pair! Our leave-in treatment protects, hydrates, and conditions the hair, while the serum seals in the moisture and provides a glossy finish with ingredients like argan oil, jojoba oil, annatto oil, and sunflower oil.

How often should I use it?

You can use the hair serum as often as you like; just be sure to avoid your roots while styling!