ZO Skin Health Review: Unhealthy Inactive Ingredients?

ZO Skin Health Review: Unhealthy Inactive Ingredients?

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ZO Skin Health is a skincare brand that’s been highly-lauded by reviewers, and is founded by a dermatologist named Zein Obagi. The brand has won awards from Cosmopolitan, Reader’s Digest and Good Housekeeping and sells products for everything from skin brightening to anti-aging to acne reduction and more.

But do ZO Skin Health products contain research-backed ingredients for improving skin quality? Does the brand use any questionable additive ingredients? How do real users rate and describe the aesthetic effects of ZO Skin Health? And which retailer sells ZO Skin Health for the best prices?

In this article we’ll answer all of these questions and more as we review the ingredients in some of ZO Skin Health's best-selling products based on clinical studies, to give our take on whether or not they're likely to be effective, and whether or not they're healthy.

We'll review Exfoliating Polish (an exfoliator) and Growth Factor Serum (an anti-aging serum).

We'll also feature unsponsored customer reviews, share our concerns about some of the brand's clinical claims, and provide a cost comparison to show which retailer sells ZO Skin Health for the best prices.

Exfoliating Polish | Ingredient Analysis

Zo Skin Health Exfoliating Polish ingredients

The ingredients in ZO Skin Health Exfoliating Polish are shown above.

The brand claims that the magnesium oxide crystals “slough away dead skin cells” which has the effect of “leaving skin instantly soft and smooth.”

The brand fails to cite these claims at the time of updating this article, and we can't find any clinical studies suggesting that topical magnesium oxide has any beneficial dermatological effects.

This formulation does have some research-backed active ingredients.

Melaleuca alternifolia (tea tree) leaf oil is an essential oil that may have the ability to improve damaged skin.

A medical review published in the International Journal of Dermatology documented that tea tree oil can be effective at treating acne and seborrheic dermatitis (dandruff) due to its antimicrobial effect.

Our issue with this ingredient listing on ZO Skin Health’s website is that the concentration isn’t published. Tea tree oil, like most essential oils, can be damaging to skin at too high of a concentration.

Glycerin is clinically shown to positively impact skin hydration and skin barrier function.

Tetrahexyldecyl ascorbate is an ester of vitamin C.

ZO Skin Health claims this ingredient “helps to brighten skin,” however, we would disagree with this assessment. 

A 2021 medical review on tetrahexyldecyl ascorbate found that this ingredient is ineffective for improving skin quality unless another stabilizing compound is included in the formulation (which ZO Skin Health Exfoliating Polish doesn’t have):

“[Tetrahexyldecyl ascorbate] may itself lack stability within the dermal microenvironment. This study showed that [tetrahexyldecyl ascorbate] has limited oxygen radical absorbance capacity and undergoes rapid degradation when exposed to singlet oxygen…This degradation, however, could be prevented by the addition of acetyl zingerone.”

ZO Skin Health Exfoliating Polish has several ingredients that we recommend consumers avoid for health reasons.

Fragrance provides no dermatological benefits and may be unsafe.

As we discussed at length in our recent review of Nexxus Shampoo, fragrance may be harmful to human health based on some clinical studies.

Green 6 is an artificial dye, and artificial dyes can be absorbed through skin according to medical research, and may be harmful to human health.

The study authors of the above-linked research review state the following: “The consuming public is largely unaware of the perilous truth behind the deceptive allure of artificial color.”

Overall, we consider ZO Skin Health somewhat likely to improve skin quality. However, we can't find any clinical evidence supporting the brand's exfoliation claims.

We don't currently recommend this product due to the inclusion of artificial dye and fragrance.

A YouTube creator and esthetician named "rachel grace" has a popluar Exfoliating Polish review:

Questionable Clinical Claims

Zo Skin Health questionable clinical proof

The ZO Skin Health website has a page titled "Clinical Proof" with claims such as the one above.

The claims are just presented as summaries, with no links to the full studies at the time of updating this article.

We urge ZO Skin Health to either provide proof of these claims of clinical efficacy, or remove them from their website. We consider this to be a red flag about the brand.

We strongly recommend that consumers entirely disregard claims of clinical efficacy made by skincare companies unless their products, or the ingredients in their products, are proven to be effective in clinical trials published in peer-reviewed journals. 

This is the gold standard for product research, and this is the type of research we cite on Illuminate Health to form our opinion about the potential efficacy and safety of cosmetics.

Presenting highlights from "clinical studies" without sharing the full studies with potential customers is a highly questionable business practice in our opinion.

Growth Factor Serum | Ingredient Analysis

Zo Skin Health Growth Factor Serum ingredients

The ingredients in ZO Skin Health Growth Factor Serum are shown above.

The brand claims that this product can reduce the appearance of fine lines and wrinkles, which makes it an anti-aging product.

There are some research-backed active ingredients in this formulation.

Hydrolyzed sericin is a novel compound derived from silkworm that's shown in a medical review to reduce wrinkles, improve skin elasticity and improve skin hydration.

Dipeptide diaminobutyroyl benzylamide diacetate was studied in a clinical trial for its effects on facial wrinkles.

86% of participants reported reduced wrinkles around the eyes after three months of treatment with dipeptide diaminobutyroyl benzylamide diacetate, and 71% of participants reported reduced wrinkles around the upper lip.

Tocopherol, more commonly known as vitamin E, is a good choice for an anti-aging because of its photoprotective effects.

As referenced in our Beautycounter reviews article, this ingredient has significant clinical backing for its ability to reduce the damaging effects of UV rays on skin.

There are two inactive ingredients that we consider to be questionable from a health perspective in this serum.

Fragrance is an ingredient we recommend avoiding, for reasons described in the previous Ingredient Analysis section.

Phenoxyethanol is a synthetic preservative shown in a 2020 clinical trial to be toxic to human cells.

Overall, we consider ZO Skin Health Growth Factor Serum likely to be effective for anti-aging, given its multiple effective ingredients. However, we don't currently recommend the product because it contains fragrance and phenoxyethanol.

A YouTube creator and doctor named Ania Marie has a review of Growth Factor Serum with over 25,000 views:

Real Customers Review ZO Skin Health

Amazon is a better resource for honest customer reviews than a brand's website in our opinion.

ZO Skin Health Exfoliating Polish is currently the brand's most-reviewed product on Amazon, with over 1,000 reviews and an average review rating of 4.6 out of 5 stars.

The top positive review from a verified purchaser comes from an anonymous Amazon Customer who gives the product a 5/5 star rating, and claims it's had an anti-aging effect:

“My aesthetician introduced me to the product and naturally when I ran out I turned Amazon to re-order. My complexion is much clearer dark spots have faded and my skin tone is smoother. I highly recommend this product!”

The top negative review from a verified purchaser is written by a user named “Eva” who gives the product a 1/5 star rating, and claims that the product is illegitimate and not from the real manufacturer:

“I have used Z products and usually I buy it from my dermatologist, however, this time I ordered from Amazon seller. The product is diluted not 100% the real product, the box is Z obagi but the first impression when you see the box you would know that it was used and diluted.”

We have no way to verify the above allegation.

ZO Skin Health Exfoliating Polish currently has an average review rating of 4.8 out of 5 stars on Google.

ZO Skin Health currently responds to all customer complaints on the brand's Better Business Bureau (BBB) page, which is a sign of a high-quality brand.

ZO Skin Health Program Review

A YouTube creator named Sydney Nicole has a review of one of ZO Skin Health's programs, which is a set of multiple ZO Skin Health products that are used daily.

She shares her thoughts on whether the products are worth the high price, and includes before-and-after images:

Our Clean Skincare Picks

There are skincare products containing ingredients shown in clinical trials to be effective for reducing wrinkles and improving skin quality.

Annie Mak Vitamin C Serum is our top anti-aging serum.

It contains hyaluronic acid which was described as a "skin-rejuvenating biomedicine" in a medical review due to its ability to reduce wrinkles and signs of facial aging.

HYDRAGLOW by CLEARSTEM is our top moisturizer pick.

It features bakuchiol as an active ingredient which was described in a 2014 clinical trial as "clinically proven to have anti-aging effects."

Bulletproof Collagen Powder is our top skin supplement.

Collagen supplementation was shown in a medical review published in the Journal of Drugs in Dermatology to reduce visible signs of skin aging as well as improve skin elasticity and skin hydration.

All of the products recommended in this section are entirely free of ingredients that we consider to be unhealthy or unsafe.

Where to Buy ZO Skin Health for the Best Price

ZO Skin Health is sold at a variety of online retailers.

Here's a price breakdown for a one-time purchase of the two products reviewed in this article, at the time of updating this article:

Exfoliating Polish (2.3 ounces)

Brand website: $68 (free shipping, link)

Amazon: $52.99 (free shipping, link to Amazon listing)

Walmart: $25.53 (free shipping, link)

Growth Factor Serum

Brand website: $168 (free shipping, link)

Walmart: $160.71 (free shipping, link)

Amazon: $97 (free shipping, link to Amazon listing)

Third-party sellers currently have better prices on ZO Skin Health than the brand's website, but purchasing directly from the manufacturer may be a safer choice.

Pros and Cons of ZO Skin Health

Here are the pros and cons of ZO Skin Health in our opinion:


  • Many effective active ingredients
  • Likely to have an anti-aging effect
  • Positive customer reviews
  • Brand responds to customer complaints
  • Uses some novel ingredients not easily sourced elsewhere
  • Free shipping from brand's website


  • Contains fragrance
  • At least one product contains artificial dye
  • Relatively expensive
  • Questionable clinical claims of efficacy
  • Growth Factor Serum contains phenoxyethanol
Stay up-to-date on our research reviews


ZO Skin Health has formulations that impress us from an efficacy perspective, and fail to impress us from a health perspective.

Exfoliating Polish contains some active ingredients that are clinically shown to support optimal skin health, but we can't find any exfoliating ingredients, and the brand's claim that magnesium oxide is an effective exfoliating agent is not cited at the time of updating this article.

This product also contains fragrance and artificial dye.

Growth Factor Serum contains active ingredients clinically shown to have an anti-aging effect, but also contains fragrance and a synthetic preservative.

We don't currently recommend either product due to the inactive ingredients.

There are a number of "clinically proven" claims on the ZO Skin Health website that we disagree with from an ethical perspective, because no link to the full studies are provided. This prevents consumers from making an informed purchase decision.

Most of the customer reviews that we came across while researching this article were positive.

At the time of updating this article, Amazon and Walmart currently have the best prices on ZO Skin Health.