Once Or Twice...I have purple so I have to keep the colour in as much as possiable I dry shampoo if it gets to greesy.
I am lucky though my hair stays so dry after 5 days not shampooing it, if you shampoo it too much it getst even more greesy...but once I wash my hair is looks awful and fluffy. so when I do wash my hair i won''t leave the house till a day after its settled.