Gentle ingredients
Once again, for the ppl in the back: All hair dyes include some chemicals, because that’s what’s required to give your hair a semi-permanent or permanent color change. But there are a few things to keep in mind if you want to keep it as natural as possible: Look for dyes made with moisturizing and protective oils, along with formulas free of alcohol, ammonia, and PPD. These three ingredients can not only dry out hair but potentially lead to skin irritation, so if you see it anywhere on the box and you’re sensitive, just put it back and keep on lookin’.
The coverage
If you’re still a little unclear on the difference between permanent, semi-permanent, and demi-permanent hair dyes, here’s the basics: With semi-permanent dyes, “there’s no developer, there’s no hydrogen peroxide—the color just sits on the hair’s surface for about 15 washes,” Patty Slattery, AVP of hair color education, training, and testing at L’Oréal Paris, has told Cosmo.
Demi-permanent dye washes out after three to four weeks and is “great for people who want to amp up their existing color, like making chestnut-brown hair richer and shinier,” added Slattery. Neither semi- or demi- or glosses are great at covering grays, so if that’s your main goal, choose a permanent hair dye instead, which “penetrates deep into the cortex of your hair.”
The amount
K, this one sounds obvious, but “almost every person underestimates the thickness of their hair,” celebrity hairstylist Cynthia Alvarez has told Cosmo. So check the instructions on how much dye you’ll need before you walk out of the store, and if you’re on the fence, pick up an extra box of dye in case. “You don’t want to be left with a section of hair that’s not colored due to lack of product,” she warned.