Prose, Function of Beauty, Formulate: What’s the difference between these custom hair care brands?
What do we need to look for when vetting all the different personalized hair care brands?

Prose, which launched in 2017, can create 79 trillion different hair care formulas. (Photo: Prose)
PERSONALIZED HAIR CARE
A number of modern hair care brands are promising customers they’ll never have a bad hair day again.
Through the use of algorithms, questionnaires and even their customer’s own DNA, the likes of Function of Beauty, Prose, Formulate and others are able to whip up shampoos and conditioners that have been customized to the individual needs of each shopper.
The big idea is that, by creating formulas that respond to factors such as the customer’s specific hair type, their diet and more, we will all be able to have the kind of healthy, bouncy hair seen in the “after” shots on a shampoo ads.
But can filling out a quick survey really result in a product that's better for you and your hair? And do consumers really need trillions of different shampoos to choose from? We asked the customizable hair care brands to explain how their formulation processes work, so we could compare.
How do customizable hair care brands decide what’s going into your shampoo?
The process is pretty uniform across the hair care brands, starting with a quiz, which is then checked over by an internal team. The surveys ask a fairly uniform set of questions, which include information about a customer’s hair type, thickness and styling methods commonly used, as well as things like geographical location, diet and what the customer’s personal hair goals are.
Formulate, for example, which launched in January 2019, takes in 25 different data points through its quiz, while Ravel, based in India, gives customers 20 questions to answer. Prose and Ravel say that, in total, they assess around 85 different factors when creating their formulas.
Standing out from the pack is Strands, a customizable hair care company that launched in April 2020. It asks customers to send in samples of their hair for internal analysis.
How many possible formulas can they create?
An unfathomable amount. Function of Beauty — the first customizable hair care brand to launch in 2015 — says on its website that it can create more than 54 trillion different combinations of ingredients, up from 12 billion reported in 2017.
Prose says it can create over 79 trillion different formulas. Ravel also says that it can create “trillions” of different formulas, and that the number is “always increasing, since we improve the formulas and test new actives on a constant basis,” says founder Ayush Varma.
The reality, however, is that just because a hair care brand can create an almost infinite number of formulas, that doesn’t mean it actually does in practice. Osmaan Shah, the founder of Formulate, says that number of combinations are “technically infinite” using his brand's 3D-printing-like process to create formulas. “But frankly, it’s just ridiculous to focus on possible combinations, or to say there are trillions of combinations like some companies do,” he adds. “With Formulate, most customers initially fall into one of 5,000 formulas.”
When Function of Beauty launched in Target in December 2020, its formulation process was rejigged so that it could work in an in-store environment. In Target, customers can combine one of four base shampoos with a possible 10 “booster” packets, meaning it offers thousands of combinations in this format — not trillions.
What gives each customizable hair care brand its competitive edge?
The fact Function of Beauty is available to shop at Target gives it a convenience factor that the other customizable hair care brands currently can't compete with.
Formulate says the way it produces its products sets it apart from the other personalized hair care companies. “We spent several years pre-launch building the manufacturing platform that runs Formulate, including the customer app and dispensing robots,” Shah says. “We don’t use pre-made formulation bases like [our competitors]. We construct each formula from the ground up, dispensing each ingredient separately. This [practice] gives us the power to make small manipulations to your formulas over time, based on feedback.”
Prose says that its advantage is also in manufacturing — in 2020, it started using a new kind of fulfillment machine that can reprogram itself depending on the formulas it is dispensing, meaning it can churn out bottles of shampoo four times quicker. “We believe that no other beauty brand is currently doing this with the precision and scale [of] Prose,” cofounder Arnaud Plas says.
Ravel says that it relies heavily on the input from its hair care experts, who assess a customer’s quiz answers before recommending a formula to them. “What we observed is that people don’t really know what they want, and could end up submitting contradictory details,” says Varma. “For example, someone with an oily scalp could add ‘deep condition’ and ‘hydrate’ as their primary goals. [That] final formula would be counterproductive.”
Are customized shampoos really better than ready-made ones?
This one is a tricky question to answer. Of course, the customizable hair care brands that Thingtesting spoke to claimed that there was indeed a need for their products, pointing out that most mass-market hair care products are unable to address hair concerns on an individual level.
It’s true that customers, generally speaking, aren’t happy with what’s on the market at the moment. According to analysis by AI data company Revuze, reviews for hair care products were increasingly negative in 2020, the year it analyzed consumer sentiment. Hair products “experienced a steep decline,” with sentiment around shampoos and conditioners down 2.4% year-on-year.
Whether or not a customized hair care brands' formulas are actually better than what else is on the shelves will likely come down to customer preference. With eight in 10 people not properly assessing their hair type before buying their shampoos and conditioners, the brands touting personalization do perhaps have an advantage in that they make you actually think about what your needs are.
Do customers actually stick with these brands?
No matter how innovative they say their formula-choosing algorithms are, perhaps the best way to judge whether or not these brands’ products are effective is to look at how many customers actually stick with them.
When asked by Thingtesting, Formulate reported that 64% of its customers in February 2022 were repeat customers. Prose says that 50% of its customers are subscribers, while Ravel reports a repeat custom rate of 45%, and a net promoter score — that is, the percentage of customers who are enthusiastic about a brand versus the percentage that are unhappy — of 78. (Anything above 50 is generally considered to be a good score.)
Function of Beauty and Aura Hair Care did not respond to our requests for comment, but in a February press release, Aura claimed to have sold 65,000 personalized orders since it launched in January 2021, while Business of Fashion has reported that Function of Beauty made $100 million in net sales in 2020.