Buy Now: https://bigpharmausa.com/pain-relief/hydrocodone-10-325mg/ The white/ oval pill imprint M523 has been identified as Acetaminophen and Hydrocodone bitartrate 325 mg / 7.5 mg. M523 pills are meant to be used to relieve moderate to severe pain. They’re typically prescribed by your doctor to relieve short-term pain. For example, if you just had back surgery, then your doctor might prescribe you M523 pills to help you with the pain from surgery. However, they’re not usually given to patients with long-term pain (such as ongoing back pain) because they can be addictive.