Coffee is so much more than a morning pick-me-up. Beauty insiders know that the grounds can be used for everything from crafting a DIY soap to exfoliating away rough skin, but despite its versatility, there's one treatment they shouldn't be used for: hair colouring. Recipes are spreading across the internet touting the ingredient as a safe, natural dye, but some professional colourists are sceptical.
"Coffee is meant to be ingested," Rita Hazan, celebrity colourist and owner of Rita Hazan Salon, told POPSUGAR over email. "There are better alternatives to colouring your hair such as using vegetable dyes or henna, which are also natural."
Other pros use the beverage for this unexpected beauty hack, but only in conjunction with other methods. Master colourist and co-founder of Spoke & Weal salons Christine Thompson has used coffee to tint strands by blending it with henna. Instead of using water to turn henna powder into a pigmented paste, you mix in hot coffee.
"Both the temperature and the acid helps the henna to adhere," she told POPSUGAR via email. She wouldn't recommend using it as a standalone hair colour, though. "I have not seen this work for grey coverage. It is not dark enough to deepen brunettes," Thompson said. "The effects are essentially minimal until washed or wiped off." Think about it: even if you spill coffee on a white shirt, the stain will still come out pretty easily in the wash, meaning that any colour will be just as temporary in your hair.
Using coffee on light strands is especially a bad idea. "It will most likely make blond hair a muddy colour," Hazan warned. Instead, try a product that was actually developed to add a brunette tint. Hazan likes her Ultimate Shine Gloss in Brown, which adds dimension to deeper strands. If you're looking for a natural solution, Aveda offers a line of organic hair dyes that are free of parabens and petroleum-based chemicals but also gentle on your strands, so your colour will last longer.
If you're still hellbent on incorporating coffee into your colour regimen, you can try Thompson's henna method, but note that henna will permanently stain your hair. "If you have hair darkened with henna, it is very difficult to lighten," she cautioned. "If you frequently colour your hair, I would stay away from henna."