Sig code: dosage form
ER medical abbreviation
ER has 2 common meanings: "extended release", "estrogen receptor". The context of the note or order decides which one is meant.
Each meaning matched at least two public references (3 in all for ER), checked October 23, 2026. The table lists them.
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2 meanings of ER
| Meaning | Latin origin | Where used | Checked against |
|---|---|---|---|
| extended release | None | Prescriptions, Medication labels | |
| estrogen receptor | None | Prescriptions, Medication labels |
Example
Sample label text: "ER tablet."
A made-up line that shows the abbreviation in place. It is not about any patient and is not an instruction.
Related abbreviations
Elsewhere on Rivvi
Questions
What does ER mean in medical terms?
ER has 2 common meanings: "extended release", "estrogen receptor". The context of the note or order decides which one is meant.
Where is ER used?
ER shows up in prescriptions and medication labels. Its category here is sig code: dosage form.
Is ER on the Joint Commission Do Not Use list?
No. ER is not on the Joint Commission Do Not Use list or the ISMP error-prone list as checked on October 23, 2026.