Pill Identification: A Complete Guide for Patients and Caregivers
Finding an unknown pill - whether in a family medicine cabinet, dropped on the floor, or encountered in another context - is a situation that occurs more frequently than most people realise. In the United States alone, poison control centres receive over 2.1 million calls per year, with a significant proportion involving unidentified medications. Knowing how to safely and accurately identify an unknown pill is an essential patient safety skill. This guide covers the three main methods of pill identification and when to use each one.
Method 1 - Imprint Code Identification (Most Reliable)
Every prescription drug sold in the United States is required by the FDA to bear a unique imprint code - a combination of letters, numbers and/or symbols embossed or printed on the tablet or capsule. This regulatory requirement means that imprint-based identification is the gold standard for pill identification. The imprint code uniquely identifies the drug name, manufacturer and dosage strength. Our Pill Identifier by Imprint Code searches a comprehensive database of these FDA-registered imprint codes. To use it effectively, examine both sides of the tablet carefully under good lighting, note all letters, numbers and symbols exactly as they appear (including any spaces or slashes between them), and enter the complete imprint in the search field. Many tablets are scored - they have a line allowing them to be broken in half - and each half may display only part of the imprint.
Method 2 - Color and Shape Identification
When a pill's imprint is worn, illegible or absent - as can occur with very old medications, chewed tablets or some uncoated supplements - color and shape identification provides a secondary approach. The FDA recognises approximately 10 standardised pill shapes and dozens of standard colors. Filtering by multiple physical characteristics simultaneously significantly narrows down the possibilities, though this method should never be used as the sole basis for identification. Color and shape filtering is most useful when combined with any partial imprint information that can be recovered. Common pill shapes include round, oval, oblong, capsule-shaped, diamond, pentagon, hexagon, figure-8 and D-shaped.
Method 3 - Capsule Identification
Hard gelatin and HPMC capsules present unique identification challenges because they lack the embossed imprint codes of tablets. Instead, capsules typically carry printed text or codes on their body and/or cap. Our Capsule Identifier specialises in this form factor, allowing search by the two-tone color combination (e.g. red/white, blue/clear), capsule size (standardised from 000 to 5), any visible printed markings, and whether the capsule has a coloured band at the join. Soft gel capsules (commonly used for fish oil, vitamin E and some prescription drugs) are typically identified by color and any embossed markings on the gel surface.
When Color and Shape Are Not Enough
It is important to understand that color and shape alone are never sufficient for definitive identification. Dozens of different drugs may share the same color and shape - for example, small round white tablets include aspirin, metformin, paracetamol, metoprolol and hundreds of other drugs. The imprint code is what makes identification definitive. If you cannot read an imprint, take the pill to your local pharmacy - pharmacists have professional-grade identification resources and the expertise to assist. Never consume an unidentified pill based on visual characteristics alone.
Medication Safety and Storage
Many pill identification situations arise from poor medication storage practices - pills stored outside their original packaging in mixed containers, or old prescription bottles with faded labels. The best way to prevent the need for pill identification is to keep all medications in their original, labelled packaging and dispose of expired or unwanted medications safely through a pharmacy take-back programme. If you are unsure about any medication's storage requirements, our Drug Storage Condition Guide provides specific storage instructions for hundreds of medications. For patients managing multiple medications, our Medication Schedule Planner can help organise complex regimens and reduce confusion.
Pill Identification and Drug Interactions
Once you have identified a pill, you may wish to check whether it is safe to take alongside other medications you are currently using. Our Drug Interaction Checker allows you to enter up to 20 medications and instantly screen for all pairwise interactions. If you have identified a pill that you were not expecting to find in a regimen, our Multi-Drug Regimen Analyzer can help assess how it fits within the complete medication picture.