Following on from the nostalgic #2000s beauty challenge and the questionable lip glueing challenge, there’s a new viral TikTok trend making the rounds and it involves purple shampoo – a lot of it. 

As anyone with bleached hair will know, using purple shampoo can help tone your hair,  removing any warm brassy undertones to keep your locks icy and cool.

The fact that the hack only really works on very blonde hair, however, does not appear to be stopping the girls (and horses, see below) of TikTok. They are using entire bottles of purple shampoo on their dry, oftentimes very brown, hair all in the name of the #PurpleShampooChallenge.

The hashtag has now racked up 4.1 million views, while #purpleshampoo is at 67.5 million views. More often than not, the final “transformations” are… not at all different to the original hair. Don’t let that stop you from enjoying the process though. 

Here we’ve rounded up some of the best.