What is the square barcode on my prescription package?
· 4 min read
If you have picked up a prescription recently you may have noticed a small square barcode, made of scattered dots rather than stripes, printed next to or instead of the familiar striped one. It is not decoration, and it is not the same as a QR code you would scan for a website.
What it is
It is a GS1 DataMatrix code, and unlike the striped barcode it can carry several pieces of information at once. On a prescription package it typically holds four:
- A product identifier that contains the National Drug Code — which drug, which strength, which manufacturer
- A serial number unique to that individual package
- The lot number the package came from
- The expiration date
The striped code on older packaging generally carries only the first of those.
Why it appeared
The Drug Supply Chain Security Act required the pharmaceutical supply chain in the United States to move to serialised, traceable packaging, with full enforcement arriving at the end of 2025. The purpose is to make counterfeit and diverted medicine harder to move: every package can be traced, and a package that should not exist can be identified.
It was designed for wholesalers and pharmacies rather than for patients. But because the information is right there on the box, it is useful to whoever scans it.
What it means for you
Two things worth having. Expiry stops being something you have to find and read in small print — the code carries it. And recall checking gets sharper, because recalls are issued by lot, and the code carries the lot.
If your package does not have one
Plenty still do not, and that is not a warning sign. Packaging printed before the changeover is still working its way through the supply chain, over-the-counter products are not covered by the same requirement, and a pharmacy vial filled from a large stock bottle carries the pharmacy's own label rather than the manufacturer's package. In those cases the NDC printed on the label does the same job, just without the lot and expiry riding along.