Medicines and prescriptions
What Does Extended-Release Mean on a Medicine Label?
Extended-Release · say it: ek-STEN-did ree-LEESAlso written: ER, XR, XL, SR, sustained-release, modified-release, MR, controlled-release, CR, long-acting, LA
Short answer
Extended-release means a medicine is designed to release its active ingredient slowly over many hours, so it is often taken less often.
What it means
Ordinary tablets release their medicine quickly after you swallow them. Extended-release versions use special coatings or structures so the medicine is released gradually over time.
This can keep levels in the blood steadier and allow fewer doses a day. Labels show it with letters after the name, such as ER, XR, XL, SR, CR, MR or LA. The exact letters differ between makers and countries.
Many extended-release tablets should not be crushed, split or chewed, because that can release the whole dose at once. Always follow the label or ask a pharmacist.
Where you may see it
- Prescription labels and medicine names
- Pharmacy information leaflets
- Hospital medication lists
📄 How it looks on a report
Metformin XR 500 mg PO once daily with evening meal
🙅 What it does not mean
- Extended-release is not the same as a stronger medicine; it changes how the dose is released, not the ingredient.
- An extended-release version cannot always be swapped with the immediate-release version at the same schedule.
- Extended-release tablets often should not be crushed or chewed, even if it makes swallowing easier.
🗒️ Questions to ask your doctor
🧾 Reports where you will see “Extended-Release”
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💊 Medicines whose labels mention “Extended-Release”
Plain-English explanations of each medicine, from its official FDA label.
- Bupropion Hydrochloride
an aminoketone antidepressant, a type of medicine used to treat depression
- Insulin Glargine
an insulin analog, a long-acting man-made insulin used to treat diabetes
- Metformin
a diabetes medicine of the biguanide type
- Morphine Sulfate
a strong prescription opioid pain medicine (the label describes it as an opioid agonist)
- Nifedipine
a calcium channel blocker of the dihydropyridine type
- Quetiapine
An atypical antipsychotic medicine
🔗 Read more from trusted sources
- “Extended-Release” on MedlinePlus ↗
US National Library of Medicine
- NCI Dictionary definition ↗
US National Cancer Institute: “er”
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General information about a medical word, not advice about your own results. Ask the clinician who ordered the test what it means for you.