Off Patent

About the data

Where the dates come from

Every date comes from the FDA's Orange Book, its list of approved drugs with the patents and exclusivities their makers have listed. Off Patent uses the Orange Book data files as of October 9, 2026. The site doesn't update by itself, so patents added or removed after that day are not here.

The FDA takes a patent off its list some time after it ends, so the dates already past come from older copies of the same files, from December 2025 on, kept by the Internet Archive.

What counts

  1. A medicine is one brand application to the FDA (an NDA) with all its strengths. Only strengths on sale, by prescription or over the counter, count.
  2. A medicine loses its listed protection on the day its last listed patent and its last exclusivity have both ended. One medicine can have many patents, but it counts once, on that last day.
  3. The site covers medicines whose last listed protection ends between January 1, 2026 and December 31, 2027.
  4. The home page shows this month, worked out from your own device's date.
  5. US only. Biologics are mostly missing, because the FDA lists almost no patents for them in the Orange Book.

What the dates don't mean

A listed end date is not the date a generic goes on sale. Patents can be extended, challenged in court or settled, and a company can list new patents. A generic also needs its own FDA approval, and its maker decides when to launch it. So a generic may come earlier, later or not at all.

Off Patent only repeats what the FDA lists. It is not legal or medical advice. For decisions about a medicine, ask a pharmacist or a doctor; for decisions about a patent, ask a patent lawyer.

Words on the site

  1. Patent. A patent the company listed for the medicine, with the date it ends.
  2. What a patent claims. The FDA notes whether a patent claims the drug substance (the active ingredient), the drug product (its form or formula), or a use, which the FDA gives a code like U-141.
  3. Pediatric extension. Six more months the FDA adds to a medicine's patents and exclusivities after studies in children.
  4. Exclusivity. A period the FDA grants after approving something new, such as a new chemical entity, an orphan drug or a new use, during which it holds back some generic approvals. Each has an FDA code, like ODE-282.