Your hair is as unique as you are, so why settle for a product made for everyone else? At Function of Beauty, we believe great hair starts with great science. Through a personalized quiz, we decode your hair's exact structure, goals, and needs to formulate a product that is truly, molecularly yours. Straight, wavy, curly, or coily, every hair type has a distinct architecture that demands a distinct formula. What gives straight hair that greasy look is the very thing coily hair is thirsting for. That is not a flaw in the product; it is a flaw in the one-size-fits-all approach. We threw out that playbook entirely. Function of Beauty crafts each formula from the ground up, engineered around your hair, because the best hair product in the world is the one made specifically for you.
Your hair type influences how natural oils travel, how moisture moves through the hair fiber, how products absorb, and how your strands respond to styling. Straight, wavy, curly, and coily hair each has distinct structural characteristics that influence how they retain moisture, distribute oils, and respond to products.
Below, we'll break down the best custom products for every hair type and explain the science behind why they work.
Straight Hair
Recommended for Straight Hair: Custom Hair Serum
Straight hair has a round follicle structure that allows sebum, your scalp's natural oil, to travel easily from root to tip. While this gives straight hair its natural shine, it can also make strands look oily, flat, or weighed down more quickly than other hair types.
That's why our Custom Hair Serum is designed with a lightweight blend of Jojoba Oil and Sunflower Seed Oil that smooths the hair cuticle without creating excess buildup. The formula enhances the shine straight hair naturally produces, helps control flyaways and frizz, and provides heat protection during styling, all while maintaining movement and volume. It works with straight hair's structure, delivering smoothness and protection without the heavy feel that can leave finer strands looking limp.
Wavy Hair
Recommended for Wavy Hair: Custom Styling Primer
Wavy hair exists in two states at once. Its S-shaped pattern creates uneven oil distribution, often leaving roots feeling oily while mid-lengths and ends feel dry. This unique structure can also make waves unpredictable, with some sections holding definition while others lose shape or become frizzy.
Our Custom Styling Primer is designed to support the balance that wavy hair naturally needs. Formulated with Provitamin B5, it helps protect strands from heat styling, UV exposure, and color-related stress while supporting moisture retention throughout the hair fiber. Because waves often benefit from a little encouragement to reach their full potential, this lightweight primer creates an ideal foundation for hot tools without weighing hair down. The result is enhanced definition, smoother texture, and protection against the daily stressors that can disrupt your natural wave pattern.
This formula works with the biology of wavy hair, helping maintain the delicate balance between hydration, protection, and movement that waves need to look and feel their best. This custom formula uses provitamin B5 to provide the ultimate protection against outside irritants like color, UV, and heat (up to 450°) damage.
Curly Hair
Recommended for Curly Hair: Custom Hair Mask
Curly hair's spiral structure makes it difficult for your scalp's natural oils to travel from root to tip. As a result, curls are often drier than other hair types and can lose moisture more quickly through naturally lifted cuticles. What may feel like chronic dryness is often a reflection of your hair's biology, not a sign that something is wrong.
Our Custom Hair Mask is designed to replenish the moisture that curly hair naturally struggles to retain. Powered by Argan Oil and Jojoba Esters, this rich conditioning treatment helps nourish the hair fiber, smooth the cuticle, and support softness and elasticity. By delivering concentrated hydration where curls need it most, the formula helps reduce dryness, improve manageability, and enhance the definition of your natural curl pattern.
For best results, use twice weekly and leave on for 5-10 minutes before rinsing. It's a simple way to give your curls the deeper nourishment their structure demands.
Coily Hair
Recommended for Coily Hair: Custom Leave-In Conditioner
Coily hair has the most complex structure of all hair types. Its tight bends and turns make it difficult for natural oils to travel down the hair shaft, while its more porous cuticle allows moisture to escape quickly. This combination often leaves coily hair feeling dry, fragile, and prone to breakage, not because it's damaged, but because of how it's built.
Our Custom Leave-In Conditioner is designed to support coily hair's unique moisture needs while helping define its natural pattern. Formulated with Avocado Oil and Coffee Seed Extract, it delivers lasting hydration to strands that naturally struggle to retain moisture. At the same time, its versatile formula doubles as a styling product, providing definition, softness, and light hold whether applied to wet or dry hair.
By combining treatment and styling in a single step, this leave-in works with coily hair's structure, helping maintain moisture, support manageability, and enhance the shape of your natural texture without compromising movement.
When your products align with your hair's natural structure, great hair days become less about managing symptoms and more about supporting how your hair is designed to behave.