A startup Glambot is generating $1 million by selling used makeup

Buying a pre-owned shirt from a thrift shop or a lamp from an antique store is common. Even fashionable.

But used makeup? There's still a huge gross factor, and Karen Horiuchi is making it her mission to fix that.

Her company, Glambot, buys used makeup from people looking to offload their extras, then cleans it all before listing it for sale online.

While many envision pre-owned make-up to be the dregs of a tube of lipstick or powder that's already used up, Glambot's instituted a rule that anything coming in has to be at least 50 percent full - and the price is based on how much is left.

Glambot cleans and sanitizes everything that comes in the door: whether it's using heat or alcohols to sterilize containers or cleanly removing layers of product to get down to a fresh one.

There are certain items like mascara and lip gloss that can't be sold because they have a reusable applicator, but items like lipstick, blush, and even makeup brushes are listed on Glambot.

Horiuchi, who has degrees in law and biotech, was on a trip abroad when she realized she had brought several containers of pretty much the same purple shade of eye shadow. 

She wanted to make some money selling it instead of throwing it away, but realized Amazon and eBay don't accept used makeup. People looking to buy cheaper or discontinued versions of their favorites were relegated to forums and Craigslist, Horiuchi told Business Insider. 

She started Glambot as a side-business in 2013, but in the past year the team has grown to 12 people and is on track for $1 million in sales.

By setting the minimum number of products that can be sold to Glambot to 20, Horiuchi has found that most of their sellers are people within the industry who receive extra samples and freebies or make-up obsessed people who take good care of their products anyway.

"To be honest, most of the make-up that comes in is barely touched," Horiuchi said.