Nioxin Review: Can Shampoo Really Thicken Hair?

Nioxin Review: Can Shampoo Really Thicken Hair?

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Nioxin is a hair care brand that sells products for thinning or balding hair. The brand claims that their products are “developed specifically for thinning and fine hair.” The brand's most popular products are hair "systems" that contain shampoo, conditioner and treatment.

But does Nioxin use research-backed ingredients for hair thickness? Does the brand use any questionable additives? How do real users rate and describe the effects? And how does a dermatologist review Nioxin?

In this article we’ll answer all of these questions and more, as we analyze the ingredients in Nioxin Shampoo, Nioxin Hair Regrowth Treatment and Nioxin Scalp Relief Treatment to give our take on whether or not the products are likely to be effective, and whether or not they're healthy.

We'll also share a review from a board-certified dermatologist, feature customer reviews including before-and-after images, and explain why we disagree with some of Nioxin's marketing claims.

Nioxin Shampoo Ingredient Analysis

Nioxin System 2 Shampoo ingredients list

The ingredients in Nioxin System 2 Shampoo are shown above.

This formulation does contain some research-backed ingredients for hair growth and hair quality.

Peppermint oil was shown in a clinical trial published in the Toxicological Research journal to cause hair growth when applied topically.

After 4 weeks, the animals receiving the topical peppermint oil treatment had 740% more hair follicles than the control group, and the treatment was found to be equally effective to minoxidil, which is the drug ingredient in hair growth products like Rogaine.

Camellia sinensis leaf extract is another botanical ingredient we consider effective for a hair thinning shampoo.

A 2019 medical review on this plant's uses in cosmetics stated the following: “Cosmetic preparations containing tea extracts are recommended for patients with androgenetic alopecia and hair loss, regardless of gender.”

It appears that topical application of tea extract decreases dihydrotestosterone (DHT) formation, and this hormone can cause balding.

Serenoa serrulata fruit extract has demonstrated efficacy for hair growth.

A clinical trial examined whether topical application of this botanical ingredient could increase hair count in men with male pattern baldness. The researchers found that average hair count increased significantly by week 12. 

There are some additive ingredients in this formulation that we consider unhealthy.

Blue 1 is an artificial dye. As we documented in our review of skincare brand Maelys Cosmetics, artificial dyes are in some cases contaminated with carcinogens, and there is mixed research on their overall toxicity.

Methylparaben is a type of paraben, which is a class of compounds described in medical research as hormone-disrupting chemicals, and according to the linked research study they are easily absorbed by the human body. 

Sodium benzoate and phenoxyethanol are synthetic preservatives, the latter of which was shown in a 2020 clinical trial to be toxic to human cells.

Overall, we consider Nioxin Shampoo likely to be effective for improving hair growth and thickness due to several clinically-backed ingredients.

However, we don't currently recommend the product due to the inclusion of artificial dye, synthetic preservatives and parabens.

YouTuber Tests Nioxin

A YouTube creator named Robin James tried Nioxin for four weeks and included before-and-after images:

Hair Regrowth Treatment Analysis

Nioxin Hair Regrowth Treatment ingredients

The ingredients in Nioxin Hair Regrowth Treatment are shown above.

It's worth noting that this product isn't currently sold on the brand's website, but on third-party retailers like Ulta.

Nioxin Hair Regrowth Treatment for men contains a concentration of 5% minoxidil, while Nioxin Hair Regrowth Treatment for women contains a concentration of 2% minoxidil. 

Minoxidil is one of the most well-studied chemical compounds for delaying balding and aiding hair regrowth in both men and women when applied topically to the scalp.

An extensive medical review on minoxidil for hair regrowth concluded that the compound provides “remarkable benefits.” It can improve both hair growth and hair density when applied daily over a long enough duration.

We don’t understand why Nioxin’s hair regrowth treatment for women has a lower concentration of minoxidil.

As we detailed in our review of Rogaine for Women, medical research has shown a 5% concentration of minoxidil to be more effective than the 2% concentration, and just as safe.

While we do consider Nioxin’s hair regrowth treatments likely to be effective, we don't currently recommend them for cost reasons.

At the time of writing this article, a one-month supply of Nioxin Hair Regrowth Treatment for women (5% minoxidil concentration) costs $35.98 at Ulta.

Other brands like Kirkland Signature sell 5% minoxidil products for under $20 at the time of updating this article.

The good news is that all of the ingredients in this formulation should be safe and non-toxic.

Dermatologist Reviews Nioxin

One of the most popular YouTube reviews of Nioxin is from a dermatologist named Dr Dray with over 130,000 views:

Scalp Relief Treatment Analysis

Nioxin Scalp Relief Treatment ingredients

The ingredients in Nioxin Scalp Relief Treatment are shown above.

Aloe barbadensis leaf juice, more commonly referred to as aloe vera, does have relieving properties.

A medical review published in the Italian Journal of Dermatology and Venereology found that aloe vera was effective for treating a number of skin conditions, including inflammation.

Glycerin is proven to have a number of positive effects on skin, such as optimized skin hydration and skin barrier function.

Boswellia serrata gum is derived from a plant native to Africa, and a clinical trial found that boswellic acids, which are chemical compounds in Boswellia serrata, confer anti-inflammatory properties to skin, and may reduce visible signs of skin aging.

Phenoxyethanol is a synthetic preservative that was shown in at least one clinical study to be toxic to human cells, as we documented in the first Ingredient Analysis section in this article.

Fragrance is included, and a medical review on fragranced consumer products found that they are a risk to consumer health, and found that there is a lack of safety testing data on some of the compounds used to make fragrance.

Overall, we consider this product likely to be effective for scalp relief, but we don't currently recommend it due to the inclusion of synthetic preservatives and fragrance.

Questionable Clinical Claims

questionable clinical claim on Nioxin website

Nioxin, like many skin and hair care brands, claims that their products are “clinically proven” to work. 

As shown above, the brand claims that their Night Density Rescue product is "clinically proven" to boost hair density. 

However, there is no link to the full clinical study, and we can't identify any studies on any Nioxin product published in peer-reviewed journals.

We recommend that consumers be extremely wary of brands making claims of clinical efficacy without publishing the full study to support those claims, particularly if those claims aren't based on research published in peer-reviewed journals.

Customers Rate Nioxin

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

Nioxin's System 2 Shampoo has over 9,000 reviews on Amazon, and an average rating of 4.7 out of 5 stars at the time of updating this article.

A top positive review from a verified purchaser comes from a user named “Nimari” who gave the product a 5/5 rating, and claims it stopped hair loss:

“This is the best ever for us a little up in age who find they start shedding like a persian cat...My hair now actually stays on my head instead of on my clothes, my hairbrush is no longer full of hair every time I brush and I love the fresh smell and light tingle in the scalp when this is used with the conditioner.”

A top negative review from a verified purchaser is written by a user named “G. Brown” who gave the product a 1/5 rating, and claims it's poorly-formulated:

“This is so thin and runny that I can't even put it in my hand. It just runs off and I end up wasting a good amount of it. It's like water.” 

Nioxin currently has an average review rating of 4.5 out of 5 stars on Facebook.

Our Clean Hair Growth Picks

Happy Head Topical is our top hair growth solution.

This formulation uses FDA-approved hair loss ingredients like minoxidil which is clinically shown to increase hair count by 11%.

Momentous Zinc is our top value hair growth solution.

A 2022 medical review on the use of zinc in dermatology concluded that "This review has found evidence to support the use of hair loss disorders."

MBG Omega-3 Potency+ is our top hair thickness pick.

Supplementation with omega-3 fats and antioxidants is clinically shown to improve hair density, and MBG's supplement contains both.

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

Nioxin Pros and Cons

Here are the pros and cons of Nioxin in our opinion:


  • Effective ingredients
  • Hair Regrowth Treatment contains FDA-approved ingredient
  • Positive Amazon reviews
  • Positive Facebook reviews


  • Contains synthetic preservatives
  • Some products contain parabens
  • Some products contain synthetic dye
  • Some products contain fragrance
  • Questionable claims of clinical efficacy
Stay up-to-date on our research reviews


We don't currently recommend any Nioxin products.

While the brand does have some impressive formulations in regard to efficacy, many of their most popular products contain additive ingredients like fragrance and artificial dye that health-conscious consumers may wish to avoid.

Nioxin's Hair Regrowth Treatments for men and women are free of questionable additives, but the same active ingredient (minoxidil) can be obtained much cheaper from other brands. 

Nioxin claims that their products are "clinically proven" to work, but fails to clearly publish the full clinical studies to support those claims, and we can't find any studies on Nioxin products in peer-reviewed journals.

The brand does have favorable reviews on both Amazon and Facebook.