Customer concern and a pending criminal charge pulled the product from store shelves. But that didn’t stop Craze from making a comeback. Craze V2 hit the market this past April. Although the company removed the meth-like compounds in the original formula (called, innocuously, dendrobium orchid extract), opponents of the new product say Craze’s return highlights a big problem with the supplement industry: The fact that there’s no one protecting consumers. MORE: 5 Anti-Aging Supplements That Work Even if you spoke supplement-labelese and could recognize the likes of dendrobium orchid extract, you still wouldn’t always get a complete picture of what’s really in the supplements you take. As of now, the FDA has listed more than 560 tainted supplement, some of which contain ingredients that aren’t mentioned on the label. Scientists concerned about supplement use, like the Harvard researchers who found the hidden danger in Crave, sometimes take product testing into their own hands. Here, three that have been recently revealed to contain unsavory additives. (And before you despair, here’s how to takesupplements safely.) Gluten in probiotics Probiotics are good for your digestive system—and can be an especially important support for people with celiac disease. But researchers from the Celiac Disease Center at Columbia University recently tested 22 popular probiotic supplements, and found that 55% of them contained gluten, the proteins found in grains like wheat that are harmful for people with celiac disease. Even supplements labeled “gluten free” contained at least trace amounts of gluten. Although the supplements have not been recalled, the scientists who published the study hope it will prompt more doctors to ask about supplement use. Antidepressants and Viagra in weight loss supplements Body Fat Breakthrough Weight-loss aids take the cake in the tainted-supplement department—the FDA has issued so many recalls for them that they get their own page on the agency’s “tainted supplements” list. Among the most recent offenders are supplements like Fatloss Slimming Beauty and Natural Max Slimming, which were called out earlier this year for containing hidden antidepressants and sildenafil, the active ingredient in Viagra. Neither supplement has been recalled. Another common compound found in weight loss supplements is sibutramine, which is known to dangerously increase heart rate and blood pressure. (Skip the sketchy supplements and see how you can lose 30 pounds in 30 days with the.) MORE: 21 Healing Herbs And Supplements Doctors Prescribe NSAIDS in pain supplements For the most part, pain supplements seem to be pretty safe. The FDA has listed only 7 tainted pain supplements since 2013. But 4 of those 7 warnings were issued within the last year, and the side effects associated with tainted pain supplements are dangerous. Supplements like Ortiga, Pro ArthMax, and Asihuri Plus Forte have been found to contain non-steroidal anti-inflammatory drugs (NSAIDs) that haven’t been regulated, and could cause problems like heart attack, stroke, ulcers, and internal bleeding, according to the FDA. Many of them also contain antihistamines—the common allergy medication—that could cause unwanted drowsiness. The FDA has not recalled these products, but is advising consumers not to purchase or use them.