A recall affecting extended-release (ER) metformin tablets has been expanded after additional lots tested above acceptable limits for NDMA. Metformin is one of the most commonly prescribed medications for type 2 diabetes, and many patients take it daily over long periods. Because of that long-term exposure, recalls related to impurities are treated seriously—even when the immediate risk to a single person may be low.
If you currently take metformin ER, do not stop your medication suddenly without medical guidance. Instead, check your prescription bottle for the manufacturer and lot information, and contact your pharmacy or prescriber for next steps if your product is included.
At a glance
- What: Expanded recall of certain extended-release metformin tablets
- Why: NDMA levels detected above acceptable limits in additional lots
- Main concern: NDMA is a probable human carcinogen with risk tied to long-term exposure
- What to do: Check manufacturer/lot info, contact your pharmacy, and follow provider instructions
- Do not stop abruptly: Uncontrolled blood sugar can be dangerous—seek medical guidance before changes
What is NDMA?
NDMA (N-nitrosodimethylamine) is a nitrosamine impurity that has been found in certain medications and products. NDMA is classified as a probable human carcinogen, which means exposure over time may increase cancer risk. Regulatory agencies set limits intended to keep risk very low, and recalls may be initiated when testing shows levels above those limits.
The presence of NDMA does not mean an immediate toxic effect is expected from a single dose. The concern is primarily related to long-term, cumulative exposure—especially for medications used daily for months or years.
Why extended-release metformin is often involved
NDMA can form during manufacturing, storage, or chemical reactions involving certain ingredients and processing steps. Some extended-release formulations and production processes may be more vulnerable to nitrosamine formation. Recalls often target specific manufacturers, lots, and strengths rather than all metformin products.
How to check if your metformin is affected
Recall eligibility is usually determined by the manufacturer and lot number. Here’s how to check:
- Look at your prescription bottle label: It may list the manufacturer/distributor.
- Check the lot number: Some pharmacy labels include the lot; if not, the pharmacy can look it up.
- Confirm your formulation: Recalls often involve extended-release (ER) tablets, not immediate-release.
- Call your pharmacy: Pharmacies can confirm whether your lot is included and arrange a replacement if needed.
If you use mail-order pharmacy services, check your shipment paperwork and contact the provider’s support line for recall verification.
What patients should do now
If you think your metformin might be included in the recall:
- Do not stop medication abruptly: Stopping metformin suddenly may cause blood sugar to rise.
- Contact your pharmacy first: Ask if your lot is affected and request a replacement or different manufacturer.
- Contact your prescriber if needed: Especially if you cannot get a replacement quickly or if your regimen needs adjustment.
- Continue monitoring: Follow your normal blood sugar monitoring plan and report unusual trends.
- Keep documentation: Save photos of your bottle label and any recall notices for your records.
What to expect from a replacement
If your product is included, pharmacies typically replace the medication with:
- A non-recalled lot of the same medication/strength
- A different manufacturer’s metformin ER product
- In some cases, a switch to immediate-release metformin or another medication—only if your prescriber recommends it
Replacement availability can vary by region and supply. If there is a delay, ask your prescriber what the safest temporary option is for your specific medical situation.
Possible side effects and what to watch for
NDMA contamination generally does not cause short-term symptoms in most people. However, metformin itself can cause side effects. Contact your healthcare provider if you experience:
- Severe or persistent stomach upset, vomiting, or diarrhea
- Unusual fatigue or weakness
- Symptoms of high blood sugar (increased thirst, frequent urination, blurry vision)
- Any new or concerning symptoms that you believe may be medication-related
If you have kidney disease, liver disease, or other conditions, follow your clinician’s guidance closely when making any medication changes.
Frequently asked questions
Should I stop taking metformin right now?
Do not stop taking prescription medication without medical guidance. Contact your pharmacy to confirm whether your lot is affected and ask your prescriber about safe alternatives if needed.
Is all metformin affected?
Typically no. Recalls usually apply to specific manufacturers and lot ranges, often focused on extended-release formulations.
What if I can’t find my lot number?
Your pharmacy can usually look up lot information using your prescription record and their inventory logs.