Can You Crush Metformin ER Tablets?
No, do not crush, chew, or split metformin extended-release (ER) tablets. They use a matrix or osmotic system to release the drug slowly over 24 hours. Crushing destroys this, causing rapid release and higher risk of side effects like lactic acidosis, nausea, or low blood sugar.[1][2]
What Happens If You Crush Them Anyway?
The full dose dumps at once, spiking blood levels and potentially causing GI upset, diarrhea, or severe acidosis. Generic versions like metformin ER from Teva or Mylan have similar coatings—none are safe to crush.[3]
Why Is Metformin ER Different from Immediate-Release?
Immediate-release metformin can be crushed since it dissolves quickly anyway. ER versions (e.g., Glucophage XR, Fortamet) are formulated for once-daily dosing with controlled release, so altering them turns them into immediate-release equivalents, which doctors avoid prescribing together.[1][4]
Safe Alternatives If You Can't Swallow Pills
- Switch to immediate-release metformin tablets, which split easily.
- Liquid metformin suspension for those with swallowing issues.
- Ask your pharmacist for scored tablets or ask your doctor about crushing only if it's immediate-release—never ER.[2][5]
When Might Crushing Be Okay?
Only for immediate-release metformin, and even then, confirm with your pharmacist as some coatings affect absorption. ER forms like Glumetza explicitly warn against it on labels.[3]
[1]: FDA Label for Glucophage XR
[2]: Drugs.com: Metformin ER Crushing Info
[3]: GoodRx: Why You Shouldn't Crush ER Pills
[4]: Medscape: Metformin Formulations
[5]: WebMD: Metformin Dosing Options