The counterfeit market isn’t limited to just handbags and designer clothing anymore—much to our dismay, knockoff makeup and fragrance sales have been on the rise. Though websites like eBay and Amazon do their best to regulate the sales of fake products, counterfeits by MAC, Urban Decay, Benefit, and Estée Lauder, among other luxury brands, tend to slip through the cracks. Not only are you buying a bootleg product, but you also expose yourself to some serious health risks. Rather than a healing blend of aloe and vitamin E, many knockoff goods contain beyond-harmful ingredients like cyanide, arsenic, rat poison, urine, and lead that definitely shouldn’t be in your household, much less your makeup. Over in the UK, luckily, police in London have already begun to crack down on counterfeit makeup sales, and with their Wake Up—Don’t Fake Up! campaign, are urging consumers to be suspicious of counterfeits, and to shop only at brand-approved retailers. Because there are a few really good fakes out there, we put together four ways to tell if the product you bought at a discount price is a dud.