Actress Kristen Bell ‏has urged fans to change their bathroom routine in a bid to save water.

The Forgetting Sarah Marshall star has teamed with bosses at beauty brand Neutrogena for their latest campaign, which aims to help conserve five million gallons of water.

Bell has vowed to cut the use of tap water while cleaning her teeth, and has called on her fans to do the same.

In a post on her page, she writes, "This month I pledge 2 (to) shut off the tap while brushing my pearlys. Come on... this is a good challenge 4 (for) us!"