HOUSTON, Texas (KTRK) -- If you've been to a convenience store recently, you've seen them. They're usually behind the counter and they promise sexual satisfaction. But do you really know what's in those brightly colored pills?"We have had people suffer very serious emergency surgeries that are requiring penile replacement surgeries," said attorney Robert Tauler.Tauler's law firm has filed a lawsuit against 15 Shell convenience stores in our area. He claims the stores are illegally selling sexual supplements that contain the main ingredient in Viagra, which is only available with a prescription.The Food and Drug Administration doesn't regulate the pills because they're classified as dietary supplements, but they are warning customers not to consume "Rhino" brands.The pills are manufactured overseas and are sold under several different names."That's all they do is change the name because they know they can beat federal law enforcement for now. And that's where we step in. We're civil enforcement," Tauler said.Emergency medical physician Dr. Erik Antonsen says there's no way for customers to know what's inside over-the-counter supplements."You could be potentially interfering with other medications or real medical problems that you have, and not catching things that need to be diagnosed and dealt with in an appropriate manner," explained Dr. Antonsen.Eyewitness News has reached out to Shell for comment, but haven't heard back.