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What Ingredient in Shampoo Causes Hair Loss?

Vicky Davis

Reviewed by Vicky Davis, FNP

Written by Geoffrey Whittaker

Published 10/23/2022

Updated 10/24/2022

Shampoo has come a long way since it emerged on the consumer market during the first half of the 20th Century. Since then, the small ingredients list of a simple natural surfactant and some fragrances has evolved into a seeming laundry list of things designed to help keep your hair clean and healthy.

But are any of them worth taking a closer look at? What ingredient in shampoo causes hair loss?

If you’re here waiting to find out that all rosemary-scented shampoos with green bottles cause alopecia, we’re sorry to let you down. Sources of scalp irritation in hair products are typically avoided by the likes of Johnson & Johnson, and ingredients in shampoos that cause allergic reactions, rob your hair of moisture, or cause dry hair to become more brittle aren’t the sort of things a company wants to put in their products.

For the most part, most of today’s hair care products are tested before they hit the market. 

Of course, there are limits to that testing. 

Things evolve and change, and new studies make new discoveries about the harsh chemicals and toxic chemicals that are part of your hair care routine. Remember the whole “Asbestos is great for insulating your home” thing? Or when people thought it was a good idea to coat their walls in lead paint?


If your ultimate goal is to steer clear of dangerous hair health hazards in the toiletry aisle, you’re going to be very busy keeping an eye on every study that comes out. Luckily, for the most part, there are only a few semi-common ingredients that may be included in shampoo that have the potential to cause hair loss

Wait… Isn’t shampoo supposed to be good for your hair? Well, yes, and for the most part, it is. 

These days, shampoo ingredients are selected for their potential for helping hair stay healthy. That may mean reducing frizz, which can increase your breakage risk. And medicinal additives might help you treat viral or fungal infections, make your hair strands less dry or brittle to avoid hair breakage, preserve softness and reduce your risk of psoriasis, alopecia or dermatitis symptoms. 

Generally speaking, shampoos and their combination of ingredients are considered safe and effective — even capable of doing things like repairing hair damage. And, as you probably suspect, any strong ingredient known to be dangerous is avoided by most manufacturers. 

When you compare that on its face with the products used to color, straighten or style your hair, the risk of damage is significantly lower with shampoos because they’re not inherently designed to manipulate the structure of your hair. 

Shampoo’s benefits aside, there are ingredients that could be considered hazardous to your hair’s health, and while they don’t appear in everything, they might be in your bathroom right now. 

hair loss treatment

balding can be optional

The shampoo ingredient list that you might encounter today that could be damaging your hair is relatively short, but there are two key ingredients to be aware of. 

The first is formaldehyde and the rest of the aldehyde family of chemicals. 

Formaldehyde has antibacterial and preservative properties and is often used in household products. While the first result of that is your hair becoming more shiny and smooth, the second is that it causes breakage to the hair.

Oh, and that’s in addition to the numerous dangers, including the increased risk of cancer associated with formaldehyde. No joke: the gasses released by formaldehyde in straightening products when heated can be a skin irritant, as well as increase your risk of developing asthma and, yes, potentially cancer.

The second is a group of chemicals known as surfactants. These chemicals (specifically, a type called sulfates) are essentially soap. Their purpose is to remove dirt, grime, grease and other things from the surface of your hair and scalp. 

They do this largely by having a different pH balance or polarization than the molecules of “dirt,” which in turn causes them to bond to those things before you wash them away.

There are two major issues with surfactants: 

  • They can damage your healthy hair by the nature of how they work (not to mention the potential for irritation and inflammation).

  • They can over-clean your hair, removing too much of the natural oil that protects your hair follicles from breakage.

Aside from these two chemicals, hair cosmetic products are largely considered safe and effective.

Since there are ingredients that could cause excessive hair loss, there might be some ingredients that fight hair loss, right?

How many different ingredients out there can help your hair loss fighting efforts and can also fit into your shampoo? Many, actually. A variety of vitamins and minerals are probably the best place to start. 

All of the following ingredients can improve hair health and growth:

Studies have also explored the following natural ingredients for suspected benefits, with modest findings:

There are even DHT blocking shampoos to consider if you’re looking to target hair loss with every wash — our hair thickening shampoo is a great example.

Natural ingredients may indeed yield some benefits and could even be part of the best shampoo for men with thinning hair, but as part of a shampoo formulation, they’re not even close to as clinically significant and proven as some other treatments. Let’s talk about those.

There are other was to prevent hair loss, of course — you don’t need to switch up your shampoo to incorporate them into your life either.

Male pattern baldness or androgenetic alopecia is generally best managed by a combination of good lifestyle choices and medications. There are two main medications most often recommended to men: finasteride (also known as Propecia®) and minoxidil, which you may know as Rogaine®.

While minoxidil’s mechanism of action for helping hair growth isn’t fully understood, it is believed to work by increasing blood flow to your hair follicles.

Finasteride, meanwhile, works to reduce hair loss by stopping your body from converting testosterone into dihydrotestosterone, or DHT, which is considered the main culprit in male pattern hair loss.

Most importantly, talk to your healthcare provider. If you’re noticing more hair at the bottom of the shower drain or on your pillowcase in the morning, or even if you’re noticing some visible thinning on parts of your scalp, your first move should be reaching out to a healthcare provider and seeking some guidance.

Modern shampoos are filled with all types of ingredients, and that could definitely be a little unnerving if you’re trying to keep your hair healthy. 

While research is always being conducted and we’re always learning and discovering new things, you can rest easy knowing that the stuff on your shampoo label isn’t going to make you go bald.

If you’re experiencing enough hair loss to the point where you suspect your shampoo is a possible suspect, it may be time to call in the pros. They’ll be able to recommend different treatment plans that make sense for your hair.

There are also plenty of ways to step up your hair protection game, from learning about your own hair type to reducing hair damage from harmful chemicals.

But if you’re seeing more hair around the drain than you used to, or finding that your comb isn’t encountering the same resistance it used to, your next move shouldn’t be binning your shampoo unless it’s brand new. 

Instead, you should be talking to a healthcare professional. Hair loss is complicated, but hair loss treatment doesn’t have to be. 

5 Sources

  1. Gavazzoni Dias MF. Hair cosmetics: an overview. Int J Trichology. 2015 Jan-Mar;7(1):2-15. doi: 10.4103/0974-7753.153450. PMID: 25878443; PMCID: PMC4387693.
  2. Ho CH, Sood T, Zito PM. Androgenetic Alopecia. [Updated 2021 Nov 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
  3. Commissioner, O. of the. (n.d.). Formaldehyde in hair smoothing products: What you should know. U.S. Food and Drug Administration. Retrieved September 5, 2022, from
  4. Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatol Ther (Heidelb). 2019 Mar;9(1):51-70. doi: 10.1007/s13555-018-0278-6. Epub 2018 Dec 13. PMID: 30547302; PMCID: PMC6380979.
  5. Ezekwe N, King M, Hollinger JC. The Use of Natural Ingredients in the Treatment of Alopecias with an Emphasis on Central Centrifugal Cicatricial Alopecia: A Systematic Review. J Clin Aesthet Dermatol. 2020 Aug;13(8):23-27. Epub 2020 Aug 1. PMID: 33178378; PMCID: PMC7595365.
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Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Vicky Davis, FNP

Dr. Vicky Davis is a board-certified Family Nurse Practitioner with over 20 years of experience in clinical practice, leadership and education. 

Dr. Davis' expertise include direct patient care and many years working in clinical research to bring evidence-based care to patients and their families. 

She is a Florida native who obtained her master’s degree from the University of Florida and completed her Doctor of Nursing Practice in 2020 from Chamberlain College of Nursing

She is also an active member of the American Academy of Nurse Practitioners.

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