Thrifting, but for beauty products. What could go wrong? The concept is undeniably budget- and planet-friendly. But unlike vintage Levi's, makeup doesn't get better with time. More importantly: "Alcohol and makeup cleansers are not necessarily enough to kill the viruses and bacteria that have been growing on and contaminating [used] makeup," says dermatologist Shari Marchbein, a clinical assistant professor of dermatology at NYU Langone. (And a wash cycle is out of the question.)

Still, it's a thing: Secondhand goods will probably comprise 10 percent of the retail market five years from now, and buying used makeup has gone nearly mainstream among millennials in Japan. On this side of the Pacific, we have Gen Z shopping hive Depop. The Instagram-eBay hybrid has 13 million users and $500 million of merchandise. While the site explicitly prohibits the sale of used makeup and proactively moderates the platform, a quick search shows that this policy is difficult to enforce. So I decided to order some stuff.

Weeks went by before my first purchase was delivered. The Benefit mascara was accompanied by a handwritten note in magenta magic marker ("Pls leave a review!"). The outer packaging was crushed, but the tube appeared brand-new — and I paid $5 less than I would have at Sephora. I'm wary of sharing mascara, but I'm devoted to my job, and I can report that the formula grips and extends my lashes just like the store-bought stuff. Days later, I felt pretty good about not having an eye infection. But when my discounted ($23) Dior face palette arrived that afternoon with a crime scene's worth of visible fingerprints on it, I couldn't bring myself to use it.

My third delivery was two-thirds of a used Chanel lipstick. At $10, it was a little over half of a lipstick at less than a third of the cost...plus some calculated risk. "Lip products are especially dangerous to share because they can harbor the herpes virus, which can cause cold sores, as well as contagious bacteria leading to superficial skin infections on the lips or elsewhere on the face," says Marchbein.

Sejal Shah, a board-certified dermatologist in New York City, echoes Marchbein's thoughts. "Used makeup can be contaminated with bacteria, fungus, or other microorganisms, which can put you at risk for dangerous infections and potentially other adverse effects as a result of these infections."

That being said, while I understand why you may be tempted to purchase lower-priced used makeup, you should be mindful of the risks associated with forgoing new products for second-hand options. As for me, despite the fiscal and environmental benefits, I'm gonna pass.

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