It’s simple to use, costs a few dollars, and saves you a trip to the salon–but there’s a good reason why boxed hair dye makes most stylists cringe. For one thing, with the exception of a few lucky women out there, most of us probably don’t possess the skills needed to mix color formulas in order to achieve a beautiful, natural hair color that is neither too ashy nor too brassy. Then there’s the dye itself, which many experts say is unpredictable and far stronger than those used in salons.
In addition to ammonia and peroxide, which can weaken hair, strip it of shine, and in some cases, cause an allergic reaction, Tsippora Shainhouse, a board-certified dermatologist in Beverly Hills and clinical instructor at the University of Southern California, says there are lesser-known chemicals in boxed hair dye that can cause skin to itch and burn or develop red rashes on the scalp, face, and even body. “Three of the top five contact allergens in adults can be found in many hair dyes: PPD (p-phenylenediamine), which is the ingredient in almost all black hair dye and black henna dyes; Formaldehyde (a preservative); and fragrance,” Shainhouse says. “These can cause a rash that may not start until a few days after you dye your hair, and it can last for weeks. In fact, it’s often persistent because women touch up their roots every 4-6 weeks.”
In addition to the dangerous chemicals, there’s also the issue of color accuracy. Marina Fuks of Serenity Hair Lounge says boxed hair dye is almost always flat, rarely ends up looking like it does on the model on the box and that it’s difficult to get out of your hair if you decide you no longer want the color. “What boxed hair color does not provide is a consultation on what color you are trying to achieve, how much grey you have, what your existing color is, if you’re trying to lighten your hair or your underlining pigment,” Fuks says. “When a professional is ready to mix your personal hair color, we have 200+ tubes of color in front of us that we choose from to create that perfect blend of color just for you.”
The reason most at-home kits just don’t cut it is simple: they are designed for one purpose and that is to cover grey hair, says Matrix StyleLink Celebrity Stylist George Papanikolas. Because they are determined to take stubborn white or grey hairs and coat them with color, they can also be more aggressive on the hair than necessary. “A professional stylist in the salon can decide if you need a semi permanent or demi permanent like Matrix Color Sync, which has no ammonia and is very gentle,” Papanikolas says. “We use them to deposit color and to refresh mid lengths and ends.”
A “one-size-fits-all” dye solution is never going to be as beautiful as salon color for another glaringly obvious reason, says Adrien Flammier, Senior Stylist at Atelier Emmanuel: your hair has its very own history and a bottle of dye alone isn’t capable of catering to its needs. “Hair is not like a sheet of white paper where whatever color you place on it stays true to the color,” Flammier says. “Hair dye reacts differently depending on the hair, whether it’s porous, already colored, damaged, light or dark. For example, someone with previously dyed blonde hair may think that it’s easy to go dark. However, their hair turned out green when using a random box hair dye instead of brown. Vice versa, someone with brown hair may think it’s easy to lighten their hair a few shades, but instead, they end up with brassy orange hair.”
You may be thinking: sure, this is all easy to say, but frequent salon trips can add up in cost. Fuks suggests looking for hair salons that provide educational classes because they may offer discounted prices for services on those days, as well as referral programs to help you bring down the price of a service. “There are multiple steps to actually achieving the perfect color, so it’s important to see a colorist,” Flammier says. “It might be more expensive than a box of hair dye at the grocery store, but the results will be much better and your hair will stay much healthier.”