Etanercept is a prescription medication used to treat inflammatory conditions including moderate to severe rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and chronic moderate to severe plaque psoriasis in adults. Etanercept is also used to treat moderate to severe juvenile idiopathic arthritis in children. This medication comes in an injectable form to be injected just under the skin, subcutaneously, usually once or twice a week. Common side effects include redness or pain at the injection site, upper respiratory infections, and headache. Take this medication only as directed. For more information, download the RxWixi mobile app.