This can last for several months in your fridge, but I don't expect that it will! (notesfromamessykitchen.com)
They have a lot of color variations with red hues (and darker ones) and the results last for several months (or longer if you wash your hair less often). (wellnessmama.com)
This puppy will last for several months too with the amount of product that it comes with, so it's actually a really good price! (kindlyunspoken.com)