Function of Beauty Review: Is Individualized Shampoo Better?

Function of Beauty Review: Is Individualized Shampoo Better?

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Function of Beauty sells extremely expensive individualized personal care products, including shampoo, body wash and more. The brand's website suggests that personalized cosmetic products can have better effects than standard commercial cosmetic products you'd find in a drug store.

But is individualized shampoo really better than regular shampoo or are these just marketing claims? Is Function of Beauty worth the high cost ($25 per bottle of shampoo)? Does it contain any questionable additive ingredients? And how do real users rate its effects in terms of look, smell and feel?

In this article we'll answer all of these questions by reviewing some of the ingredients in Function of Beauty based on medical research, sharing real, unsponsored user reviews of the product and compare the brand to other popular individualized shampoo brands like Prose.

Ingredient Review

Function of Beauty ingredients

We completed Function of Beauty's online quiz with fake answers just to get a sample ingredient list, shown above.

Even though this is the dye-free and fragrance-free version, there are still several ingredients with questionable health effects that we recommend avoiding.

1,2 hexanediol was shown in a medical review published in the Ecotoxicology and Environmental Safety journal to be potentially harmful to humans: “it is highly likely that 1,2-hexanediol is toxic to humans.”

Phenoxyethanol is a synthetic preservative. As we referenced in our review of Kristin Ess Shampoo (another popular shampoo containing this ingredient), this ingredient was shown in a clinical trial to be toxic to human cells.

Sodium benzoate and ethylhexylglycerin are also preservatives, and while we consider ethylhexylglycerin to have the most favorable safety profile of any cosmetic preservative, it seems illogical from a health perspective to use shampoo with preservatives when there are shampoos free of synthetic preservatives. 

We cannot identify a single ingredient in this formulation proven in medical research to be effective for improving hair quality. Function of Beauty shampoo contains exotic ingredients like Tremella fuciformis sporocarp (snow mushroom) extract and Aphanizomenon flos aquae (algae) extract, but we can't locate any clinical trials showing these ingredients to be effective, nor does Function of Beauty appear to cite any on their website.

Overall this is arguably the worst shampoo formulation we've reviewed on Illuminate Health, especially when considering the price. Function of Beauty shampoo contains no ingredients we identify as research-backed and effective, and several questionable additive ingredients. And this is even when considering the healthiest formulation they offer; free of artificial dye and fragrance.

We recommend avoiding this product line entirely.

Real, Unsponsored User Review

One of the most popular YouTube reviews of Function of Beauty Shampoo comes from a creator named Abbey Yung. The video is unsponsored and she shares her experience after using Function of Beauty shampoo for a month. She provides a live product demo, talks about how long the products last, and discusses how to choose hair goals on Function of Beauty's website.

This review is more focused on the aesthetic benefits and experience of using the shampoo rather than the health effects:

Does Function of Beauty Cause Hair Loss?

Function of Beauty has a somewhat notable amount of negative customer feedback online. A VICE article from 2021 reported that many customers were complaining that Function of Beauty products were causing hair loss.

Their Better Business Bureau (BBB) page is also overwhelmingly negative, with a review average of 1.08 out of 5 stars, and a significant number of complaints. Several reviewers claim the products caused hair loss.

A user named "Stefnie A" gave the brand 1 out of 5 stars:

"within the first few washes noticed a ton of my hair was falling out . I cried !!!!! I cant wash it without having clumps of hair clog my drains . I can brush it out without removing wads from the brush I cant even touch it without pieces falling out . Hair all over the back of my shirt its awful !!!"

A user named "Fe M." gave the brand 1 out of 5 stars and echoed similar sentiments:

"After using the shampoo and conditioner for a few months I've noticed an incredible amount of hair loss and thinning. I found no positive results in the products purchased."

Any brand as popular as Function of Beauty will have some negative reviews, but we find negative reviews claiming side effects like hair loss to be more notable than standard negative reviews of shampoo brands that may complain about cost or additive ingredients. There does not appear to be any active class-action lawsuit against Function of Beauty that consumers alleging damage could participate in.

These claims are another red flag about the brand in our opinion.

Function of Beauty at Target Vs. Online

Function of Beauty is sold in standard formulations at Target, and in individualized formulations online. A dermatologist named Dr. Dray compared the difference in a popular YouTube video that has over 40,000 views.

She explains which is a better option for consumers considering this brand:

Function of Beauty Vs. Prose

Many consumers are curious about whether Function of Beauty or Prose is a better option, since these are the leading personalized cosmetic brands in the U.S.

Our Prose shampoo reviews article reviewed the brand favorably, and we would recommend Prose over Function of Beauty. We have no affiliation with either brand so our recommendation is unbiased.

Like Function of Beauty, Prose has fragrance-free and dye-free versions of their custom formulations, but Prose uses some research-backed ingredients so we consider their formulations more likely to be effective. 

Prose shampoo is also free of questionable additive ingredients like synthetic preservatives, and the brand doesn't appear to have the same online user complaints about hair loss.

Questionable Product Safety Announcement

Function of Beauty published a blog post claiming that the brand "Passed Major Safety Standards."

The article details how a for-profit company called Biorus tested Function of Beauty’s products and deemed them safe.

There is no link to the testing data or even an explanation of what was tested, so this announcement is entirely useless to consumers in our opinion and should be regarded as marketing.

We urge Function of Beauty to publish the raw data, or at least a summary. If the brand could prove that their products are free of toxins or contaminants, this would be useful information for consumers, but publishing an announcement of safety data results without any link to those safety data results is quite strange and unhelpful in our opinion.

Our Non-Toxic Shampoo Recommendation

The shampoo we recommend is Acure Vivacious Volume Shampoo

This shampoo is formulated with effective and non-toxic plant-based compounds like aloe vera juice and argan oil. It also contains rosemary leaf oil which was shown in a clinical trial published in the Phytotherapy Research journal to promote hair growth.

Most importantly, this shampoo contains no questionable additive ingredients like fragrance or synthetic preservatives. It’s less than half of the price of Function of Beauty shampoo, costing only $8.49 at the time of updating this article.

Interested consumers can check out Acure Vivacious Volume Shampoo at this Amazon link.

Function of Beauty Pros and Cons

Here's our take on the pros and cons of Function of Beauty as a brand.


  • Beautiful branding
  • Some online reviewers claim improved hair quality


  • Expensive
  • Questionable additive ingredients
  • Questionable product safety announcement
  • Hair loss complaints
  • Negative BBB rating
  • Most products contain artificial dye
Stay up-to-date on our research reviews


We do not recommend any Function of Beauty products. In the individualized sample product we were assigned, we were unable to identify a single ingredient proven in medical studies on humans to improve hair quality or induce hair growth. 

Function of Beauty shampoos (even the fragrance-free and dye-free ones) contain questionable additive ingredients like synthetic preservatives that we recommend avoiding.

We believe there are shampoos on the market that are much better value, given that a one-time purchase of Function of Beauty shampoo currently costs $25.

We would recommend Prose shampoo over Function of Beauty shampoo for consumers set on purchasing individualized shampoo.

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