How Safe Is Hair-Dyeing During Pregnancy?

With up to 75 percent of women in the US coloring their hair, it’s important to find out if it’s actually safe to dye hair when pregnant.

woman hair being dyed in salon

Before deciding to color your hair, it is important to understand that not all hair dyes and coloring techniques are created equal. In fact, most conventional hair dyes contain a multitude of potentially carcinogenic ingredients. 


Types of Hair Dyes:

First we will look at the three types of hair dyes available:


Temporary dyes


These dyes stay on the surface of the hair and do not penetrate the hair shaft. They usually last 1–2 washes. 


Semi-permanent dyes


These dyes can partially penetrate into the hair shaft. They typically last 5-10 washings. The dyes used for these can be pure vegetable dyes, such as henna, or chemical dyes.  


Permanent dyes


These dyes penetrate deep into the hair shaft and create a chemical change in the hair shaft and last, essentially, until the hair is cut off. The dyes used in the US for permanent hair dyes are usually coal tar dyes. Darker hair dyes tend to use more of these coloring agents.


Some of the most popular hair coloring techniques include:


  1. Root touch up or full hair dye: for this process the hair dyes are deposited directly on the scalp each time hair is dyed.
  2. Highlights, balayage, lowlights, frosting, streaking:  the dye is painted directly onto your hair shaft and does not necessarily have contact with your scalp.

When we dye our hair, we are exposed to the ingredients in hair dye by inhalation or when our scalp absorbs them during the processing of the color.


What Chemicals are used in hair dyes?


Finding out about what’s exactly in your hair dye is actually quite challenging. According to the American Cancer Society, hair dyes can contain thousands of different chemicals. The Food and Drug Administration (FDA) is in charge of ‘regulating’ hair dyes (and all cosmetics) in the United States but in doing so they don’t actually approve each an every ingredient used before the hair dyes goes on the market. This means that manufacturers can essentially use any ingredient they desire, no matter how toxic. 

Adding to the challenge of finding out what exactly is in hair dye is the fact that, while store bought dyes have to list their ingredients, dyes that are meant for salon use (labelled “For Professional Use Only”) are not required to list their ingredients.  

This makes it hard to really know what you are being exposed to, however we do know that generally speaking, permanent hair dyes tend to contain harsher chemicals and tend to need longer processing times, which is why they are of more concern. When these chemicals are placed on your hair, while the color is being processed, you absorb them through your scalp or through inhaling the fumes. 


Common chemicals found in permanent hair dyes:


  • Ammonia: Ammonia is used in permanent hair color to open the cuticle of the hair and allow the hair dye to be deposited within the hair. According to the CDC, when inhaled, it is an eye, nose, and throat irritant and can lead to breathing difficulty, wheezing, or chest pain. Additionally it is a suspected endocrine disruptor.
  • Ethanol amines: Ethanol amines are used in some ammonia-free permanent hair colors to open the cuticle and allow the dye to be deposited inside. According to Safe, “When ethanol amines are used in the same product as certain preservatives that break down into nitrogen, they can form nitrosamines. Nitrosamines are known carcinogens. In the EU, one type of ethanol amine is banned from cosmetics due to this reason.
  • P-phenylenediamin (PPD): A common coal tar dye (derived from petroleum) that is used as a coloring agent. Coal tar dyes have been linked to birth defects, skin irritationliver and blood toxicity, and allergic reactions. It is restricted for use in the European Union, however in the US coal tar dyes do not need FDA approval and can be used in hair colors. PPD is a powerful allergen which can even cause fatal anaphylactic reactions- even when having been used without any allergic reactions in the past. The EPA classifies PPD as a known human respiratory toxicant, and as generally toxic to animals in moderate doses.
  • Toluene: This is a well known neurotoxin, with long-term exposure links to birth defects, pregnancy loss and is one of the main allergens in hair dyes. 
  • Resorcinol: This is a known endocrine disrupting chemical meaning that it mimics our natural hormones which can lead to developmental, reproductive, neurological, and immune effects. 
  • Lead acetate: This is a well known neurotoxin.
  • Fragrance: Fragrances can be made of dozens of different chemicals. Most synthetic fragrances have endocrine disrupting abilities. 
  • Formaldehyde: A known carcinogen which has been linked to cancer and fetal damage in utero.

“How much of these chemicals are actually being absorbed by you?” and “How much could make its way to your baby?” are questions that still remain unanswered. What we do know is that pregnancy and fetal development is a period of life referred to as a “window of vulnerability,” when we are most susceptible to all potential toxins. Because of our susceptibility, we recommend being extra cautious. Try to reduce your exposure to all environmental chemicals during pregnancy.

In the absence of studies confirming that dyeing your hair is safe, the best action to take is to avoid dyeing your hair when pregnant.


If you can’t avoid it, here are some general guidelines dying your hair during pregnancy:


  • Try to wait until the second or third trimester to dye your hair. The majority of fetal development has formed by the third trimester.
  • If possible avoid permanent hair color and opt for temporary or semi-permanent dyes. If you must use a hair dye, look for formulas that are made using natural herbal extracts and are free of p-phenylenediamin (PPD), ammonia or parabens. See below for our natural hair color brand recommendations. 
  • If possible opt for techniques where the hair dye is not applied directly to the scalp and is less likely to be absorbed by your body. Examples include: highlights, balayage, low lights etc.
  • Always have hair dye applied in a very well ventilated room.
  • If applying the dye at home, always follow safety recommendations like wearing gloves when applying the hair dye, and not leaving hair dye on longer than needed.


Safer Hair Color Brands


There are several hair dye brands that claim contain safer chemicals.

A stand out is Hairprint, which you can buy online to try at home. Or, if you live in Los Angeles, New York or San Francisco there are salons that apply it. What makes Hairprint different is that it doesn’t strip the hair of its color and penetrate dye. Instead, it contains 8 food grade ingredients that mimic the protein that gives hair its color in the first place and then it restores your former hair color. Hairprint is currently only available for brown and black hair.

Alternatively, Christophe Robin semi permanent hair gel is a hair color that’s free of PPD, resorcinol, ammonia, peroxide or oxidants, and is available for a wide variety of color hues.


Interviews, stories, and guides on contain information that is general in nature and should not replace professional medical advice, diagnosis or treatment. If you have a medical condition or concern or plan on trying a new diet, supplement or workout, it’s best to first consult with your physician or a qualified health professional.


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