
Function of Beauty Haircare: Our Review
Main image – Function of Beauty
Have you ever come across one of those brands so popular that you’re sure their products must be, at a minimum, slightly over-hyped?
For me that was personalised hair care brand Function of Beauty; a line of products so omnipresent in magazines and on social media that although I was keen to try, I was also fairly certain their products wouldn’t be able to tame my unruly hair.
But after testing the line for a few months I’m happy to say I couldn’t have been more wrong.
And that’s partly because beyond the genuinely child-like excitement involved in choosing the colour and scent of the products (yes I’m 5), I particularly like the chance to target five specific hair concerns in one go rather than buying a load of different products.
Committing to a minimum of $54 for a shampoo and conditioner is a bit of an ask though. That’s why we’ve set out our full thoughts on Function of Beauty’s hair care line here for anyone thinking of making the leap into custom haircare.

Image – @functionofbeauty/Instagram
This is new, up-to-date information. This article was originally published in 2019 and we updated it in June 2023 to add our further thoughts on Function of Beauty’s shampoo, conditioner, leave-in conditioner, hair serum and mask, complete with updated prices.
What is Function of Beauty?
First up though, who actually are Function of Beauty and when did they emerge on the beauty scene?
Launched in 2016, the brand is the brainchild of MIT engineers and developers, Zahir Dossa, Joshua Maciejewski, and Hien Kaplan, who decided custom haircare shouldn’t have to cost hundreds.
Fast forward a massive Instagram launch and 7 years and this custom haircare brand (offering a mind-boggling more than 87 trillion possible ingredient combinations depending on your hair care goals) is a cult beauty favourite.

Image – @functionofbeauty/Instagram
Now offering a shampoo, conditioner, leave-in conditioner, serum, mask and styling primer, the line revolves around a hair goals quiz which sees buyers customise their products online before placing their order.
The line also offers a range of beauty products, including a body wash, face wash and moisturiser.
How it works
If you’re into anything customisable, taking Function of Beauty’s seven-part hair goals quiz is probably half the fun. For anyone else though this step may feel like a bit of a faff as there are a *lot* of potential options to choose from.
In the first step you´ll tell them about your natural (untreated hair type). Choose between straight, wavy, curly and coily types, each with a handy illustration to help you choose if you’re uncertain.

Image – Function of Beauty
A second step involves picking your hair structure between fine, medium or coarse. Again, Function of Beauty offer an illustration and description if you’re not sure of exactly how thick your hair is (I wasn’t absolutely sure so this helped me).

Image – Function of Beauty
Next you’ll be asked about your scalp health, from dry to balanced or oily.
In the fourth part of the quiz the company asks about any treatments you’ve got in your hair, including highlights, bleach, keratin or perm, as well as your current hair colour.
Blonde hair shades can opt for a purple shampoo, conditioner and mask. At this point you can opt for a silicone-free formula too.
Next, is probably the most fun bit; choosing your hair goals.
Choose up to 5 goals between options like anti-frizz, colour protection, shine and volumise.

Image – Function of Beauty
In step 6 you can choose to opt out if you’re not buying a styling product since this section is based on how you style your hair and your styling goals.
Options include blow drying and straightening and goals like curl definition and volumising.
Finally you’ll get to pick the name you want to go on your bottles and the scent you’d like, as well as the strength of that perfume. Options include Floret, Coco, Mango, Rose, Peach, Lavender, Eucalyptus, or Pear. You can also go totally fragrance-free.

Image – @functionofbeauty/Instagram
After you’ve submitted your quiz, you’ll annoyingly) be asked to submit your email address before the company then gives you a list of the ingredients it will include in your formulas based on your answers.
You’ll then be asked to choose your colour from a possible 9 options, although there are often limited-edition shades to choose from too. Equally, you can go dye free if a vibrant bottle of shampoo in your bathroom isn’t your thing.
The online reviews
As with any beauty product, results are going to be completely subjective.
Despite launching to much fanfare on social media, Function of Beauty has had some mixed online reviews with many users praising the line for softening, conditioning and defrizzing hair but others complaining of lack of results or even issues like hair loss.
In response, the brand has said: “We stand behind all of our products and are confident in their safety.
“Every ingredient we use across our formulations meets both US and EU cosmetic regulations– some of the strictest in the world– and all of our formulations are reviewed by an expert toxicologist. Beyond these measures, our products are manufactured in the United States and undergo a rigorous clinical testing process to ensure safety and quality control.”
The brand’s current Trustpilot rating is still an impressive 4.1 stars from across a total of 27,736 reviews however.
But how do these Function of Beauty reviews tie in with our experience at Live That Glow HQ?

Image – @functionofbeauty/Instagram
Our review of Function of Beauty’s shampoo, conditioner and leave-in conditioner
Having ordered various different scents (peach is my favourite) and colours, for my frizz-prone, highlighted long (and fairly damaged) hair, I’ve always chosen the same hair goals.
These are deep condition, hydrate, shine, anti-frizz and colour protection, and I can honestly say the shampoo, conditioner and leave-in conditioner have always delivered on those goals for me.
My hair is noticeably softer, shinier, less frizzy and considerably more manageable when using them (and this is from someone whose hair can knot up within minutes of brushing it).
The shampoo, while sulphate-free, lathers well but I can feel that it hasn’t stripped my hair before I apply conditioner.
Meanwhile, the conditioner, designed to be left on only for a 1-2 minutes, has a thin texture which combs through hair easily and leaves my hair feeling smoother immediately after use.

Image – Live That Glow
But it’s the leave-in conditioner which is the star product for me. Again, a thin texture which applies easily (some people may find this too thin compared to heavier serums they’re used to), this conditioner seems to have exactly enough weight to keep my hair from frizzing up but without removing any volume from the roots.
Overall, I’ve been genuinely impressed to note that the three products deliver on every score.
A quick glance at the ingredients lists of each suggests this is probably due to the inclusion of hair-nourishing goodies like quinoa (containing amino acids to repair damaged hair), rice bran oil (for shine and control), and sweet almond, soybean and baobab extracts (for moisture and condition).
Since the products are heavily customised, the ingredients of each person’s formulas will vary. But for my own (somewhat wild) hair, the results have been impressive.

Image – @functionofbeauty/Instagram
In fact, after moving away to Olaplex’s own shampoo and conditioner for a couple of months (mainly just to switch things up rather than because Function of Beauty wasn’t delivering) it was my hairdresser who noticed the condition of my hair had deteriorated and suggested I go back to the customised hair care line.
A word of caution though; while my own results were far less frizzy, shinier hair, that may be largely down to how out of condition my locks were to begin with, however.
For anyone who doesn’t colour or heat treat their hair regularly, you may find you don’t gain much over your regular products here simply because there isn’t as much improvement to be had on your existing hair condition.
The hair serum
As well as the brand’s relatively new body wash and skincare line, Function of Beauty also offers a custom hair serum and mask.
I’ll be honest and say that neither of these are my favourites of their products, although those who prefer a silicone-based product may love the custom serum.

Image – Live That Glow
Created using the same hair quiz as the shampoo etc, the serum still has the same pleasing aesthetics, and the addition of your favourite custom scent helps to build up some impressively sweet-smelling hair if you’re using all the products together.
With a silicone-like feel similar to most other serums, this product applies nicely but just doesn’t have the same impact on the condition of my hair that the original three products have.
If you’re looking for a comprehensive review of this serum though, read our full thoughts here.
The hair mask
Similarly, while you would expect a mask to be even more transformative than their regular conditioner, on my own hair it actually leaves my strands feeling less conditioned.
A much thicker texture, the mask is designed to be left on hair for up to 20 minutes. Again, I chose exactly the same hair goals as for the shampoo, conditioner and leave-in conditioner.
While the results are fine (and still better than quite a few masks I’ve tried), leaving hair softer than if I hadn’t used any conditioner at all, I’m not blow away by it.

Image – Live That Glow
Again, there will be plenty of people who may well find this product does considerably more to their hair, however.
Our full thoughts on Function of Beauty’s mask are here.
How much is Function of Beauty?
Function of Beauty’s completely customised line is available exclusively on their website. Shampoo and conditioner start from $27 each for 8 oz sizes, while the leave-in conditioner is $24, the serum $29, the primer $29, and the mask $24.
Discounts are available on larger sizes if you sign up to their subscription service. They also offer free shipping with every subscription order.
Thanks to the brand’s soaring popularity you can also find a range of slightly less customisable shampoos and conditioners in store from Target in the US and from Boots and Cult Beauty in the UK. Prices are from $9.99 for a bottle of shampoo and $3.49 for a hair goals ingredients pod to put in it.

Image – Function of Beauty
While the prices for the original line are obviously higher than a supermarket buy, beyond the softer, shinier, (peachier-smelling) hair, the thing that gets me is that these bottles are actually significantly cheaper than the R+Co products they originally replaced in my routine (as well as being sulphate-free)
Don’t get me wrong, these still aren’t cheap products though and I appreciate that $27 is a lot for a shampoo. But I do think that for the service and results these might represent better value than several other luxury hair brands.
Having said that, while the products I’ve tried worked really well for my hair, I think that the sheer number of potential combinations of hair goals could end up being a little overwhelming, which could easily lead to misdiagnosing hair concerns and ending up with a custom treatment that doesn’t work for you.
The Takeaway
For someone with naturally healthy hair (lucky!) Function of Beauty’s customisable products may be something of an unnecessary luxury.
For everyone else (and that definitely includes me) who wants to tackle multiple hair issues in one product though, bring on the custom hair care routine!