Evidence: The swabs were sent to New York University's Microbiology department for testing, with 20per cent showing growth of mould, yeast, or fecal matter
The make-up testers at department stores have been revealed to be filled with bacteria, mould and fecal matter.
Good Morning America went undercover to test the safety of shared make-up testers, which on average, are switched out only once a year.
The show sampled ten stores over two states, using sterile swabs and undercover cameras to gather evidence, which were sent to New York University's Microbiology department for testing.
Allure editor-in-chief, Linda Wells, added: 'To me make-up testers are like petri dishes, I would not want to go near one. There are better ways to do it'.
Brushes and foundations were found to be the worst offenders, with make-up experts suggesting that consumers test foundations on the neck rather than the face.
With lipstick, they recommend testing colors on the pad of your finger, which, considering how many times hands come into contact with the mouth, this might need to be reconsidered.
For eyeshadow and eyeliner, which tied with foundation for the most germ-filled, it is recommended to use a disposable applicator on the back of your hands.