How to Identify a Pill by Its Imprint Code
The imprint code is the single most reliable method for identifying an unknown tablet or capsule. Every prescription drug sold in the United States is required by the FDA to bear a unique imprint - a combination of letters, numbers and symbols that uniquely identifies the drug product, its manufacturer and dosage strength. This guide explains how to read imprints correctly and how to get the most accurate result from our identifier.
Reading the Imprint Correctly
Examine the pill carefully under bright, directed light - a torch or desk lamp angled at the surface works better than overhead lighting. Use a magnifying glass if available. Check both sides of the tablet: many tablets have imprints on both faces, and both together form the complete identification code. Note every letter, number, symbol and space exactly as it appears. Pay attention to whether a dividing line is a score line (allowing the tablet to be split) or part of the imprint itself. Enter the complete imprint above - if the pill has imprints on both sides, enter them separated by a slash (e.g. "M / 5").
When the Imprint Doesn't Match
If your search returns no result or unexpected results, try these steps. First, check whether you may have confused similar-looking characters: the letter O and zero (0), the letter I and number 1, or the letter B and number 8. Second, try entering just the numeric portion of the imprint without the letter prefix, or vice versa. Third, try our Pill ID by Color and Shape tool to narrow down candidates visually. If you still cannot identify the pill, take it to a pharmacist - they have professional identification resources and the expertise to help. Never take an unidentified pill.
Pills Without Imprints
Some medications legally have no imprint: dietary supplements, vitamins, most herbal products, some OTC generics and foreign-manufactured medications are not subject to the FDA imprint requirement. If a pill has no visible imprint after careful examination, it is most likely a supplement or vitamin. Take it to a pharmacy for professional identification. Do not assume it is safe to take.
After Identification - Next Steps
Once you have identified a pill, you may want to check whether it interacts with other medications you are taking. Use our Drug Interaction Checker to screen for interactions. To check side effects, use our Side Effect Checker. For correct storage conditions for the identified medication, see our Drug Storage Condition Guide. If you need to find the generic equivalent of an identified brand-name medication, our Generic ↔ Brand Name Converter can help.