According to Trisha Torrey for About.com, pills can be identified by their shape, pattern, color and text imprint. Websites such as RxList.com and Drugs.com offer online pill identification tools where users enter the description of the pill and the website returns the best matching results.
Torrey adds that the U.S. Federal Drug Administration requires each approved pill or tablet to have a unique look to simplify its identification. Users should search for the text imprint first, and try adding the shape and color if needed. If the pill does not have any imprint, it could be of foreign origin, a counterfeit, an alternative medicine or an illicit drug. Users should avoid taking unidentified pills for risk of adverse effects from an unknown substance.