EDITOR’S SUMMARY: Reversing the appearance of aging is big business in the United States. This is especially true for women. There are a plethora of products you can buy to attempt to turn back time; hair dye included. In some camps gray hair is seen as a health imbalance, rather than a circumstance dependent on chronological age alone. Whatever your stance, making a well-informed decision about the color of the locks on your head can be empowering. Just watch out for mainstream advertising targeted at you to uphold someone else’s beauty standard.
By Tracy Reilly
It’s estimated that 50%–80% of women, and 10% of men over 40 dye their hair. Such widespread use would seem to merit scrutiny by regulators, but it is user demand that’s prompted more accessibility to seemingly safer choices in hair dye. However, as with food labels, “natural” or “plant-based” doesn’t mean the product is as “clean” or nontoxic as you might hope.
Before you assess your appropriate level of concern, here is a quick rundown of the science of hair coloring, starting with the anatomy of a hair. The outermost layer of your hair is the cuticle. Underneath that is the cortex, within which is the melanin pigment that determines your hair color. Inside the cortex, some hairs also have an air-filled space called the hair shaft medulla. Scientists don’t know yet what the purpose of this part is, nor why one hair on your head might contain a medulla and another right beside it may not. Hair dye can either penetrate the cortex in the case of permanent types, or “weakly adhere to the hair shaft cuticle” if temporary.
Between temporary and permanent dyes are semi-permanent and demi-permanent formulations. The larger the molecules in the dye, the longer the color sticks around. So while a semi-permanent color does enter the cortex, its molecules are small in size, so they typically wash away in 6–12 shampoos. Demi-permanent dyes, composed of medium-sized molecules, linger for 24–46 washes. If you’re committed to a particular color, or covering grays, that’s where permanent dye comes in.
To achieve a permanent color change, you need a “developer” or “oxidizing agent,” often hydrogen peroxide, as well as an “alkaline” like ammonia. The alkaline causes the hair shaft to swell, allowing the developer to penetrate. This is where hydrogen peroxide does double-duty. It lightens your color and causes a chemical reaction with the color molecules in the dye, enabling them to stay in your hair permanently.
The big question: Do these chemical components merit concern for your hair and your health? When it comes to your hair, there’s no way around some degree of damage since the very job of the dye’s alkaline element is to “disrupt the protective barrier of the cuticle.” This action makes your hair more vulnerable to future damage. Bleaching, specifically, oxidizes the melanin to get rid of your hair’s natural color. But melanin doesn’t just provide your hair’s color, it also serves a photoprotective function.
Upon oxidation, that function is lost, leaving your hair more susceptible to UV (ultraviolet) light damage. External damage is one thing, but what if you’re more concerned about your overall health than simply your hair alone? This raises the question: Can your hair absorb substances into your body, even if the substance doesn’t contact the scalp? The short answer is yes, but it’s not so black and white.
Take this study, for example: Scientists researching caffeine absorption via hair (for the purpose of possible future avenues of delivering medicines), found that indeed, caffeine could be absorbed not just through the follicle, but hair itself. Even when individual hair follicles were painstakingly blocked off, the caffeine entered the bloodstream, albeit more slowly and in slightly lower concentrations than with follicular exposure. Hair follicles can be such a welcoming entry point that researchers have started looking into vaccination via follicle. It’s worth noting, however, that this has been studied only in mice thus far, whose skin and hair have different characteristics from yours.
A study like this may seem alarming in regards to chemical access to your body via your hair. But before you take a vow of natural color, it’s important to note that accessibility to your body isn’t universal—it varies greatly depending on the substance to which your hair is exposed. In other words, just because caffeine can make its way from the hair to the bloodstream doesn’t mean everything else can. Some molecules such as caffeine have special properties that make them more easily absorbed.
For example, caffeine is a hydrophilic molecule, meaning it’s attracted to water, a property that makes it easier to penetrate the hair follicle. Common hair dye components like hydrogen peroxide and ammonia have other properties that make it harder for them to be absorbed. For example, they’re small molecules that either react with the hair dye or evaporate (hence the smell of ammonia-containing products—you’re smelling the ammonia evaporate) before they have the opportunity to be absorbed by your skin.
While some studies have shown that the skin around your hair (such as your forehead and behind your ears) is more absorbent than other parts of your body, the scalp itself has sebum, a waxy coating, to protect it. That’s why some dye kits provide a barrier cream (or advise using petroleum jelly) around the hairline to prevent dyeing of the skin, whereas you don’t typically see dye staining your scalp.
Ingredients of Concern
You may get nostalgic over the good ol’ days—pre-internet, pre-smartphones, and kids playing outdoors well into the night with no worries—but one thing you wouldn’t want to go back to is hair dye of old. Before 1980, hair color formulas could contain certain coal-tar compounds found to be carcinogenic to animals. Since then, many manufacturers have reformulated their hair dyes to exclude these specific elements. Unbelievable as it may be, it wasn’t until 2018 that the U.S. Food and Drug Administration (FDA) revoked approval of lead acetate use in hair dye. The maker of Grecian Formula (Combe, Inc.) objected, and the FDA suspended its lead acetate ban for several years until 2022 when it was finally reinstated. Manufacturers had one year to remove this potentially toxic component from hair color formulations.
One ingredient “clean beauty” advocates express concern about is resorcinol. Its strength is in helping your chosen color stick around longer. What concerns healthy-dye-seekers is that it can be an irritant, and some worry it may affect your thyroid. Yes, when administered to rodents at high doses over two years, resorcinol disrupted the animals’ thyroids. However, scientists determined that in real-world conditions, exposure to resorcinol in hair dyes was unlikely to cause human thyroid dysfunction.
The purpose of ammonia in hair dye is to open the hair cuticle, allowing the color to penetrate. It has been known to cause allergic reactions, skin irritation and burns, and to trigger respiratory problems. Fortunately, many companies have heard consumers’ cries and removed it from their formulas, making it easier to find options with ammonia-free alternatives. One of the most common of these alternatives is monoethanolamine, referred to as MEA. According to dye manufacturer Madison Reed:
“It does not have the odor of ammonia and does not cause eye or respiratory irritation as readily as ammonia . . . Because it is a large molecule, MEA cannot penetrate the scalp or reach the follicle from which the hair grows.”
Once ammonia, or an alternative alkaline, has lifted your hair cuticle, that’s when the actual color comes into play. For this, you need a hair color base, which typically contains one of the more concerning ingredients in hair dye: PPD (paraphenylenediamine—say that three times fast!). PPD is a coal-tar coloring agent derived from petroleum. It’s also the main reason boxed dyes advise you to do a “patch test” before slathering their concoction all over your mane. If you’ve ever had a reaction to hair dye, PPD was likely the culprit. It’s even had the distinguished “honor” of being named Contact Allergen of the Year by the American Contact Dermatitis Society.
There are no bans keeping PPD out of your dye, but more hair color manufacturers seem to be replacing it with its less-aggressive counterpart, PTD (para-toluenediamine). PTD serves a similar function to PPD but is less likely to elicit an allergic reaction. Approximately half of the people who can’t tolerate PPD can tolerate PTD. However, both PPD and PTD have been shown to penetrate the scalp during hair dyeing, making their way into the blood, and then excreted through urine. Just what effect these chemicals can have if they seep into your body is not well-researched. This argues for being especially diligent with your barrier cream, and cautious with application of your dye.
Wildly Inconsistent Data
Where many health issues are lacking in data, hair dye safety has been studied multiple times over many decades. The maddening part is that the data has been greatly inconsistent. One of the largest and longest studies on the subject was the Nurses’ Health Study. Commencing in 1976, the study followed 117,200 women for 36 years. For the most part, the news was good in that researchers found hair dye use did not cause a significant increase in the risk of most types of cancers … but in some, it did. The study found positive associations with risks of hormone receptor-negative breast cancers, ovarian cancer, and among light-haired participants, increased risk of basal cell carcinoma (a type of non-melanoma skin cancer).
Of course, it’s difficult to isolate the causes of these results. Were light-haired participants more susceptible to basal cell carcinoma because light-haired women also tend to have fairer skin? The Skin Cancer Foundation now believes that five or more blistering sunburns between ages 15–20 can increase the risk of non-melanoma cancers by 65%—data that wasn’t factored into the study. The results of the Nurses’ Study also included these perplexing findings:
“We observed potentially lower risks of lung cancer, brain cancer, and chronic lymphocytic leukemia or small lymphocytic lymphoma among ever users of permanent hair dyes and those who used larger cumulative doses. These observations are difficult to account for and warrant re-evaluation in other investigations.”
The same study finding no increase in cancer risk, some increase in cancer risk, and even a reduced cancer risk might leave you scratching your dyed (or undyed) head. Another substantial study called the “Sister Study,” comprised of 46,000 women in the U.S., resulted in some disturbing findings. Researchers recruited women who had no history of cancer themselves but had at least one sister diagnosed with breast cancer. They determined that temporary and semipermanent dye use did not result in increased breast cancer risk.
However, the “nonprofessional” application of semipermanent dyes and straighteners on others did increase the risk. Researchers posited that although gloves are generally provided in dye kits, perhaps they weren’t used, or possibly dye ended up on the appliers’ forearms. They also proposed that inadequate ventilation could result in longer and more intense exposure to toxic chemicals. The more disturbing results came with regard to participants who regularly used permanent hair color (every 5 to 8 weeks). In this group, the risk of breast cancer increased by 9 percent. When separated out by race, the increase in risk skyrocketed to 60% among Black women.
One of the study’s authors, Dr. Alexandra White, clarified that while the increased risk they found overall was 9 percent, when put in context of a woman’s average lifetime breast cancer risk (13%), the regular use of permanent hair dye increased lifetime risk only one percentage point to 14%. For Black women, however, the 60% increase raised their average lifetime risk to 21%—a considerable jump.
The scientists had no hypothesis as to why there was such a discrepancy in the numbers between races. The study also looked at straighteners and relaxers, finding an association between such products and breast cancer, a risk that grew with increased frequency of use. Nearly three-quarters of Black participants had used straighteners within the past year, so it’s possible that together, the extra load of chemicals produced a cumulative effect, but a definitive answer has yet to be found.
This is sadly consistent with a 2016 study by the Environmental Working Group (EWG). In looking at beauty and personal care products, the EWG found that 40% of those marketed to the general public scored low in potentially hazardous ingredients compared to less than 25% of those products marketed specifically to Black women. Clearly, more specific research is needed so that if you’re a woman of color, you can make informed choices to minimize your health risks. Until such research is available, you can consult EWG’s database of over 70,000 personal care products with their own safety ratings.
Do different colors matter? It makes sense that the darker the desired color, the more concentrated the potentially harmful ingredients like PPD would be. The Nurses’ Study didn’t take into account the colors of hair dye used, but other studies have, with some finding an increase in cancer risk for those using darker dyes.
But hold on. Just as something starts to make sense, here come the Sister Study’s findings. For Black women, they found no risk difference whether using light colors (blonde or light red) or dark (black, brown, auburn/dark red). However, in white women, the risk increased with light-colored shades but not with dark. It’s enough to make your head spin. These striking inconsistencies make it hard to know what the “bad guy” ingredients in hair dye formulations are, and if they’re really that bad after all. You may wonder what to look for on the label, or if it’s all just a shot in the dark.
Natural … Ish
As with so many products across industries, seeing the term “natural” on the box doesn’t mean much. There’s no regulatory requirement for what’s defined as natural, so it could mean things as simple as plant-based dyes, fewer or less-irritating chemicals (but not an absence of chemicals), or just including (but not exclusively) essential oils.
It’s generally a good sign when a manufacturer is up-front with their ingredient list. Madison Reed is one brand that claims to be a healthier kind of dye. While their products do contain PTD, they address on their website the ingredients they specifically leave out and why. Their dyes are created in Italy, and meet EU safety standards, which are more strict than those in the U.S. It comes at a price, though—running two or three times the cost of a conventional boxed dye.
The good news is that manufacturers seem to be more aware of the growing public concern over potentially harmful chemicals. There are alternative options available, and they’re becoming increasingly accessible. This means you may not have to search out Whole Foods or Sprouts markets, or another “natural” product-heavy store. You can find PPD- and ammonia-free choices at stores such as CVS and Target, which amounts to greater convenience and more affordable options. And while you won’t find it in stores, Radico is a company whose dye powders are actually 100% organic. Free of PPD, ammonia, and peroxides, their full ingredient list is readily available, and includes mostly leaves, seeds, roots, and flowers.
Beyond the Box: Ideas for Your Consideration
What if you could forget the whole cover-my-gray approach altogether, and just restore your natural color? If this route appeals, and your natural color is brown or black, you could give Hairprint a try. A relative newcomer to the hair color game, Hairprint boasts “8 food-grade nontoxic ingredients and an inert thickener,” and claims it can restore your natural color, with some exceptions. In a fascinating video, the company’s chemist explains that the way melanin molecules are “stacked” in your hair is what determines your individual hair color. This structural setup is based on your genetics and unique to each person, much like a fingerprint (hence the name). Hairprint works by putting the eumelanin protein back into your hair’s cuticle, allowing the melanin molecules to stack in the same unique way your hair originally did, restoring its natural shade.
The one caveat is that to achieve this restoration, Hairprint needs the melanin to be present in your hair. This means if you have lighter or reddish locks—blonde, strawberry blonde, red, auburn, etc—Hairprint won’t work for you. Nor will it work on currently-dyed hair because the melanin has been altered, so you’ll need to wait until your hair grows out for it to be effective. In addition, boosting the production of melanin, by way of supplementing with catalase and L-tyrosine enzymes, may prevent gray hair development. From Verywell Health, Dr. Michelle Green, M.D., in “Supplements to Prevent Gray Hair: Do They Really Work? noted”:
“The purpose of including L-tyrosine and catalase in the formulations is to ‘“prevent hair discoloration and stimulate melanin production,”’ she added. ‘“However, there is no current clinical evidence that catalase and L-tyrosine supplements can prevent or reverse gray hair development.”’
If you want to forego commercial dyes completely, there are a few fully-natural (no quotes needed) products that can lighten or darken your hair without the questionable chemicals. With the exception of lemon juice, these methods won’t be permanent like the boxed dyes that penetrate the hair shaft, but they do work temporarily. If you’re hankering for a little red in your ’do, beet juice or even carrot juice is worth a try.
Some lighter-colored testers of the beet juice method found it added a pinkish hue to their hair; darker-haired testers found that it turned their hair a darker brown. Beet dye should last about 10–15 days. Obviously, this color leaves you sooner than traditional dyes, but it’s certainly a healthier option. Beets also have the added benefit of promoting hair growth and fighting dandruff, all while steering clear of toxins.
Another option in the reddish family is henna. Made by grinding the leaves of the henna plant into a powder, then adding liquid, it becomes a mud-like paste. If the shades henna offers appeal to you, it’s just about the best of both worlds in that it has considerable staying power (experts say it usually sticks around for about two months), yet because it coats the cuticle but doesn’t penetrate the cortex, it leaves your hair’s structure and texture intact.
Those with curls, take note: it can weigh hair down a bit, loosening your existing curls to a degree, but it’s the weight, not a structural change that’s the cause. As for gray coverage, there’s some debate over henna’s effectiveness. Some say it leaves a “bright orange sheen;”others find its effect to be more akin to natural highlights, calling it “dazzling and twinkly.”
Experts caution that the exact shade you end up with can be unpredictable, so it’s best to go a shade lighter than your target with henna because you can go darker on another attempt but not lighter. So long as it’s not black henna, which contains PPD, natural henna is generally considered “safe” and well-tolerated by most. It may even help balance the pH in your hair and scalp, and make your hair shinier. However … be mindful of which box of henna you choose, and read the ingredients. Beware of products that contain propylene glycol methyl ether, a solvent and cleaning solution used for a variety of applications, or other additives. This substance may irritate your lungs, and repeated use can lead to bronchitis. Rather, source varieties that only contain “Lawsonia inermis leaf powder” (henna); preferably organic.
If you’re seeking a lighter look, grab yourself a spray bottle of lemon juice. Most effective is to apply it to your hair and leave it for at least an hour, ideally while spending some of that time in the sun, before washing it out. Again, keep in mind while the juice can be washed out, the resulting color can’t. Steeped concoctions can work well whether your goal is to lighten or darken your mane. Chamomile flowers steeped in boiling water can lighten your locks. On the flip side, dried sage steeped in boiling water can darken brunette hair and help cover grays, as can a strongly-brewed cup of dark-roast coffee.
If the chemicals in conventional dyes are a turn-off, and the natural methods seem cumbersome, here’s an alternative: You could toss the dyes and embrace your gray. From Colorado State University’s Center for Healthy Aging, “The science of gray hair”:
“Changing the narrative around gray hair is important. Holding negative views about aging has been linked to an increased risk of diabetes, a lowered ability to bounce back from disease, lower mortality rates, and a decreased ability to fight off cancer.”
Businesswoman and author of “Going Gray: How to Embrace Your Authentic Self With Grace and Style,” Anne Kreamer did just that at age 46. She believes that using color to disguise your aging actually achieves the opposite effect and can harm your confidence. How you carry yourself is the real determinant of how your vitality presents to the world.
Alas, if you’re not ready to let it all go, or you simply enjoy playing with different colors, take reasonable precautions. When using dyes, open a window for ventilation. Don’t skip over the patch test. Keep in mind that your body’s reaction to the same substance can change over time, so testing on a small area of skin is a wise move every time.
If your patch test proves benign, you’re good to go, but use protection. Be generous with barrier cream on the skin around your hairline. Mind the time recommended on the box, and try to keep the dye solution on your roots but off of your scalp. Be sure to use gloves. If you’re doing multiple “dye jobs,” choose neoprene gloves over latex or polyvinyl chloride (PVC) since PPD has been shown to start breaking through PVC gloves after 40 minutes.
If you’re pregnant (or trying) or breastfeeding, it’s best to avoid coloring your hair as some studies have shown a link between hair dye use during pregnancy and development of childhood cancer. The inconsistent safety findings may not let you wash away your worries like you can your grays, but at least these measures will keep you as safe as possible on your next color adventure.
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Published on May 09, 2024.
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