There is no way you will not have bacteria in lipsticks. I assume that even a sealed lipstick will be contaminated with some kind of bacteria.
Designer expensive lipstick will mostly give you a sophisticated look. Women splurge on makeup and may have several designer lipsticks.
Some throw the lipsticks away after few months of use but I can assure you that majority of makeup lovers will keep their expensive lipsticks for more than a year if not several years.
Storing a lipstick for a year or years will definitely attract bacteria in the lipstick.
Makeup Tip to use your lipstick for a longer time and kill any bacteria in the lipstick:
Place the lipstick in a ziplock bag or a bowl with cover.
Pop it into the freezer and let it stay in it overnight.
Remove the lipstick from the freezer in the morning and let it defrost for an hour.
Freezing the lipstick could help kill the bacteria in it.
