A round gray pill with the imprint OP on the front, and 15 on the back of it is 15mg of Oxycontin (made by Purdue Pharma).
Oxycontin, a brand of the generic oxycodone, is a narcotic analgesic that is used to treat pain, and chronic pain. Abuse of this drug may lead to psychological or physical dependence. This prescription-only medication is not proven to be a risk to an unborn fetus, but should be used only under a doctor's supervision.
On October 19, 2012, the Huffington Post reported that 16 pharmacists and others were charged with trafficking Oxycontin in Southern California.