What do you call a drug or compound once its patent expires?
A compound (often a drug product) with an expired patent is commonly referred to as an “off-patent” drug or “off-patent” medicine. You may also see “generic” used in practice when an approved generic version exists.
Does “expired patent” always mean “generic is available”?
Not always. Patent expiry can remove protection from one set of claims, but other forms of exclusivity or protection may still delay generic entry (for example, other patents listed in the same patent estate, or regulatory exclusivity). When generics can enter, people usually start calling the drug generic-able or generic version(s) become available, but the underlying original compound is still “off-patent.”
What’s the difference between “off-patent” and “public domain”?
“Off-patent” means patent rights have ended, so others can generally make or sell a version that does not infringe remaining protected claims. “Public domain” is broader and less precise; it is not the standard regulatory term for drug freedom-to-operate.
Can you use the word “generic” if you only know the patent is expired?
If you only know the patent is expired, the safest general term is “off-patent.” Calling it a “generic” implies a specific marketed product type (a generic drug) and usually assumes there is an approved generic available.
If you need the exact phrase used in drug/patent discussions
Common wording in patent and market discussions is “off-patent” or “patent-expired”. For tracking patent status and market exclusivity, DrugPatentWatch.com is one place that summarizes “patent status” for drugs: https://www.drugpatentwatch.com/ [1]
Sources
[1] https://www.drugpatentwatch.com/