Mohs Surgery
Dermatologist Scottsdale AZ Skin Cancer Scottsdale AZ
Scottsdale Dermatologist Dr. LaTowsky




WEN® to switch to new conditioner?


Over my morning cup of Earl Grey tea (yes, I'm old school with my taste in tea) I was perusing my e-mails and something caught my eye:

"FDA Investigating Hair Conditioner Product After High Number Of Complaints."

Truth be told, I never just read the headlines because more often than not, the claims are simply to create media buzz, or the snippet of data they include isn’t even applicable to real-world people, but I digress. Back to business! So after reading the article on NPR, I ended up reading the entire 29-page FDA complaint (please don’t waste your time, I promise, it’s not that interesting). In summary, it’s drafted in the standard lawyer lexicon, intermixed with anecdotal complaints from consumers who experienced similar concerns over the use of the WEN® cleansing conditioner. Specifically, the complaint states, "The FDA is investigating reports of hair loss, hair breakage, balding, itching, and rash associated with the use of WEN® by Chaz Dean Cleansing Conditioner products.” The complaint also goes on to state: "Within two weeks of beginning use of her WEN Cleansing Conditioner, Plaintiff began losing substantial and abnormal amounts of hair. Plaintiff discontinued use, but the hair loss continued for approximately three more weeks. Ultimately, Plaintiff lost one quarter to one third of the hair on her head. As a result, Plaintiff, a nurse practitioner by profession, was forced to expend substantial sums on vitamins and supplements to attempt to regrow her very long hair. Additionally, Plaintiff was forced to undertake expensive cosmetic solutions, such as hair extensions, to mask the hair loss."

Pretty scary sounding, right? How could this uber-popular product that many of my clients swear by be the complaint of so many people? I mean, especially with claims such as "WEN® is gentle enough to use every day" and "WEN® isn't like an ordinary shampoo so you want to use more of it, not less. You can never use too much! The more you use, the better the results." With the “greatest thing since sliced-bread" claims, how could you not want to use it.

Let me begin by making this very clear; for the most part, hair care products (shampoo, conditioner, styling products) are all very safe. For a product to be on the shelf of any major retailer, they must undergo rigorous testing for safety and consistency. With that said, allergic reactions can (and will) occur regardless of whether a product is "organic" or "natural." As an aside, one of my favorite things to remind patients is that poison ivy is 100% organic and natural, and that most certainly gives many people a ripping allergic reaction!

After reviewing the label, some of the ingredients may be recognizable, while others may just trigger bad memories from high school chemistry class. Nevertheless, the ingredients of the WEN® Sweet Almond Mint Cleansing Conditioner are: Water, Aloe Vera Gel, Glycerin, Chamomile Extract, Cherry Bark Extract, Calendula Extract, Rosemary Extract, Behentrimonium Chloride, Stearamidopropyl Dimethylamine, Cetyl Alcohol, Emulsifying Wax, Panthenol, Trimethylsilylamodimethicone, Hydrolyzed Whole Wheat Protein, PEG-60 Almond Glycerides, Menthol, Essential Oils, Citric Acid, Methylchloroisothiazolinone, Methylisothiazolinone, Fragrance

While most of the ingredients are nothing to write home about, the three ingredients which I highlighted, Methylchloroisothiazolinone (MCI), Methylisothiazolinone (MI), and Fragrance are. These are important to me as a Dermatologist because they are very well studied and documented as allergens and therefore have the ability to cause allergic contact dermatitis (ACD), which by the way wreaks havoc on over 72 million Americans every year.1 They garnered so much attention in fact that Methylisothiazolinone and Fragrance were awarded the "Allergen of the Year" in 2013 and 2007, respectively, from the American Contact Dermatitis Society (ACDS).

So buckle up for our ride into the world of ACD in relation to isothiazolinones (including MCI, MI, and benzisothiazolinone (BIT) and fragrance. Before we dive into the isothiazolinones however, let’s take a quick peek at fragrances. Fragrances consist of both natural and synthetic materials. Natural fragrances are derived from distilled botanical compounds, yet the difficulty in acquiring consistently high volumes of natural products has led to the subsequent development of synthetic fragrances. Nearly 90% of fragrances are synthetic compounds, which estimates to more than 5,000 different compounds. Fragrances are found in many products, such as colognes, cosmetics, medications, foods, and cleaning products. There is a predilection for fragrance allergy to occur more often in women, which may be due to the fact that 30 to 50 different substances are used to create the unique fragrance mix found in perfumes (provided that you wear perfume of course). Furthermore, fragrances are responsible for 30% to 45% of ACD to cosmetics. 

But now onto the often missed culprit of ACD….the class of chemical compounds collectively known as isothiazolinones. These ubiquitous class of chemicals are common synthetic biocides/preservatives found in many skin and hair products (as well as industrial products). Isothiazolines is that MCI/MI (in a fixed 3:1 ratio) were first registered as preservatives in the US in 1977 under the trade name Kathon CG.2 During the 80s, isothiazolinone preservatives became widely used in consumer personal care and industrial products, mostly because they are compatible with numerous surfactants and emulsifiers and have the ability to maintain biocidal activity over a wide range of pH (pH 2-9).2,3 The Environmental Working Group’s (EWG) skin database has roughly 3234 cosmetic skincare products listed to contain MI as an ingredient.4 This is a huge increase from previous reports estimating that the use of MI nearly doubled between 2007 (1125 products) and 2010 (2408 products).5

Just this year, Scheman and Severson analyzed data (from 2013) from the American Contact Dermatitis Society’s (ACDS) Contact Allergen Management Program (CAMP).6 Collectively they analyzed 4660 consumer products, which were evaluated by category and MI was found in dishwashing products (64%), shampoos (53%), household cleaners (47%), hair conditioners (45%), hair dyes (43%), laundry additives/softeners (30%), soaps/cleansers (29%), and surface disinfectants (27%).6 Nearly 100% (except 1 product) contained MI (without MCI) in household cleaning, dishwashing, and laundry products. Other product categories that contained MI (without MCI) in high percentage included moisturizers (82%), shaving products (78%), sunscreens (71%), anti-aging products (67%), hairstyling products (56%), soaps and cleansers (30%), and hair dyes (20%).6 While that is a lot of percentages (sorry), it is important to note that these products are marketed (and are allowed to be) as "hypoallergenic," "gentle," "sensitive," "organic," "100% natural," and "dermatologist-recommended," and they can contain MI. So do you see why labeling and marketing can be downright confusing to consumers (including myself)? I certainly think it is, and this stuff is part of my business.

The Cosmetic Ingredient Review expert panel re-examined their 100 ppm concentration limit placed on MI in leave-on and rinse-off products in 2013. They have maintained their opinion that "MI is safe for use in rinse-off cosmetic products at concentrations up to 100 ppm and safe in leave-on cosmetic products when they are formulated to be nonsensitizing, which may be determined based on a quantitative risk assessment."7 Currently in the US, FDA regulations mandate cosmetic products to label only the net quantity of all items, such as the weight of the whole moisturizer bottle. Although a list of ingredients from the most frequent to the least frequent appears on the product label, declaring the actual amounts of each ingredient is NOT required. Moreover, products used solely at professional establishments not sold for retail use, as well as free samples DO NOT require ingredient declarations as these do not fall under the Fair Packaging and Labeling Act.8 Pretty transparent, huh?

By now you might be curious how this all relates to hair loss? Great question…read on!

There is a condition in Dermatology called Telogen effluvium. A little background about this condition and I promise to tie it all together! Despite it sounding excessive, it’s actually totally normal to lose up to about 100 hairs a day. This is simply the result of the normal hair growth cycle. Your hair follows a programmed cycle in which it will grow for a few years, then rest for a few months, shed, and finally regrow. Telogen is the name for the "resting" stage of the hair growth cycle. Telogen effluvium is when any form of stress (whether you actually realize the stress or not) causes hair roots to be prematurely pushed into the resting state. Telogen effluvium can be acute or chronic. You see, the body loves “balance” (or homeostasis for the science-buffs out there), so any deviation to this perfectly harmonious system can send as many as 70% of the hairs on your scalp shedding anywhere up to 2 months after the "stress," much to your chagrin of course. This abrupt loss in hair, commonly described by my patients as "coming out in handfuls," is properly termed acute telogen effluvium. This is mechanistically a different problem than the rather gradual genetic thinning of the hair found in androgenic alopecia. One of the troubles with telogen effluvium is that there are a considerable number of causes. Among the common culprits are fevers, childbirth, infections, chronic illness, iron deficiency, emotional/psychological stress, surgery, thyroid disorders, crash diets, UV exposure to the scalp, and a variety of medications.

Now that we know a little bit about some causes of allergic contact dermatitis and telogen effluvium, let’s come full circle with regards to how this fits into the FDA complaint of WEN® cleansing condition potentially causing hair to fall out. A quick search of the literature will bring up a multitude of studies linking allergic contact dermatitis as a cause of telogen effluvium. And since there are three potential culprits as a cause of ACD contained in that product, we might just be onto something here. However, while the exact pathogenesis of how ACD causes telogen effluvium isn’t known, it is suspected that it may be related to cytokine release during the inflammatory process. Remember, ANY stress can be a potential cause…and that can be as simple as the repeated exposure of hair care products containing isothiazolinones (MCI or MI), as in the WEN® Cleansing Conditioner. Now while I can’t put a definitive finger on this being the cause or the reason why consumers are reporting their hair loss, what I can do is play the Derm Detective and present my findings :-)

Stay informed!

-The Skin Doc.


1. Bickers DR, Lim HW, Margolis D, et al. The burden of skin diseases: 2004 a joint project of the American Academy of Dermatology Association and the Society for Investigative Dermatology.

2. Jacob SE. Focus on T.R.U.E. test allergen #17 methylchloroisothiazolinone/methylisothiazolinone. The Dermatologist. 2006;14(7).

3. Gadberry JR. Ingredient review: the safety of paraben substitutes. Skin Inc. April 2008.

4. Methylisothiazolinone. Environmental Working Group website. Accessed April 26, 2016.

5. Castanedo-Tardana MP, Zug KA. Methylisothiazolinone. Dermatitis. 2013;24(1):2-6.

6. Scheman A, Severson D. American Contact Dermatitis Society contact allergy management program: an epidemiologic tool to quantify ingredient usage. Dermatitis. 2016;27(1)11-13.

7. Cosmetic Ingredient Review Expert Panel. Amended safety assessment of methylisothiazolinone as used in cosmetics. October 8, 2014. Accessed April 26, 2016.

8. FDA. Cosmetic labeling guide. Accessed April 26, 2016.

9. Antonella T., Piraccini BM., Van Neste D., Telogen Effluvium After Allergic Contact Dermatitis of the Scalp. Arch Dermatol. 2001;137(2):187-190.

Articles from NPR:

Darlene P.

July 28, 2016
5:08 pm
Been using this product for a while and I saw this about WEN on another site scary to imagine this happening to me! I didn't know about the stuff that is in there and learned a bunch from your post! Thanks for the info!
Enter verification code: Captcha not loaded